Amanita muscaria poisoning has occurred in young children and in people who ingested the mushrooms for a hallucinogenic experience. Occasionally it has been ingested in error, because immature button forms resemble puffballs. The white spots sometimes wash away during heavy rain and the mushrooms then may appear to be the edible A. caesarea.
Amanita muscaria contains several biologically active agents, at least one of which, muscimol, is known to be psychoactive. Ibotenic acid, a neurotoxin, serves as a prodrug to muscimol, with a small amount likely converting to muscimol after ingestion. An active dose in adults is approximately 6 mg muscimol or 30 to 60 mg ibotenic acid; this is typically about the amount found in one cap of Amanita muscaria. The amount and ratio of chemical compounds per mushroom varies widely from region to region and season to season, which can further confuse the issue. Spring and summer mushrooms have been reported to contain up to 10 times more ibotenic acid and muscimol than autumn fruitings.
Deaths from this fungus A. muscaria have been reported in historical journal articles and newspaper reports, but with modern medical treatment, fatal poisoning from ingesting this mushroom is extremely rare. Many books list Amanita muscaria as deadly, but according to David Arora, this is an error that implies the mushroom is far more toxic than it is. Furthermore, The North American Mycological Association has stated that there were "no reliably documented cases of death from toxins in these mushrooms in the past 100 years".
The active constituents of this species are water-soluble, and boiling and then discarding the cooking water at least partly detoxifies A. muscaria. Drying may increase potency, as the process facilitates the conversion of ibotenic acid to the more potent muscimol. According to some sources, once detoxified, the mushroom becomes edible. Dr Patrick Harding describes the Sami custom of processing the fly agaric through reindeer.


Muscarine, discovered in 1869, was long thought to be the active hallucinogenic agent in A. muscaria. Muscarine binds with muscarinic acetylcholine receptors leading to the excitation of neurons bearing these receptors. The levels of muscarine in Amanita muscaria are minute when compared with other poisonous fungi such as Inosperma erubescens, the small white Clitocybe species C. dealbata and C. rivulosa. The level of muscarine in A. muscaria is too low to play a role in the symptoms of poisoning.
The major toxins involved in A. muscaria poisoning are muscimol (3-hydroxy-5-aminomethyl-1-isoxazole, an unsaturated cyclic hydroxamic acid) and the related amino acid ibotenic acid. Muscimol is the product of the decarboxylation (usually by drying) of ibotenic acid. Muscimol and ibotenic acid were discovered in the mid-20th century. Researchers in England, Japan, and Switzerland showed that the effects produced were due mainly to ibotenic acid and muscimol, not muscarine. These toxins are not distributed uniformly in the mushroom. Most are detected in the cap of the fruit, a moderate amount in the base, with the smallest amount in the stalk. Quite rapidly, between 20 and 90 minutes after ingestion, a substantial fraction of ibotenic acid is excreted unmetabolised in the urine of the consumer. Almost no muscimol is excreted when pure ibotenic acid is eaten, but muscimol is detectable in the urine after eating A. muscaria, which contains both ibotenic acid and muscimol.
Ibotenic acid and muscimol are structurally related to each other and to two major neurotransmitters of the central nervous system: glutamic acid and GABA respectively. Ibotenic acid and muscimol act like these neurotransmitters, muscimol being a potent GABAA agonist, while ibotenic acid is an agonist of NMDA glutamate receptors and certain metabotropic glutamate receptors which are involved in the control of neuronal activity. It is these interactions which are thought to cause the psychoactive effects found in intoxication.
Muscazone is another compound that has more recently been isolated from European specimens of the fly agaric. It is a product of the breakdown of ibotenic acid by ultra-violet radiation. Muscazone is of minor pharmacological activity compared with the other agents. Amanita muscaria and related species are known as effective bioaccumulators of vanadium; some species concentrate vanadium to levels of up to 400 times those typically found in plants. Vanadium is present in fruit-bodies as an organometallic compound called amavadine. The biological importance of the accumulation process is unknown.


Fly agarics are known for the unpredictability of their effects. Depending on habitat and the amount ingested per body weight, effects can range from mild nausea and twitching to drowsiness, cholinergic crisis-like effects (low blood pressure, sweating and salivation), auditory and visual distortions, mood changes, euphoria, relaxation, ataxia, and loss of equilibrium (like with tetanus.)
In cases of serious poisoning the mushroom causes delirium, somewhat similar in effect to anticholinergic poisoning (such as that caused by Datura stramonium), characterised by bouts of marked agitation with confusion, hallucinations, and irritability followed by periods of central nervous system depression. Seizures and coma may also occur in severe poisonings. Symptoms typically appear after around 30 to 90 minutes and peak within three hours, but certain effects can last for several days. In the majority of cases recovery is complete within 12 to 24 hours. The effect is highly variable between individuals, with similar doses potentially causing quite different reactions. Some people suffering intoxication have exhibited headaches up to ten hours afterwards. Retrograde amnesia and somnolence can result following recovery.


Medical attention should be sought in cases of suspected poisoning. If the delay between ingestion and treatment is less than four hours, activated charcoal is given. Gastric lavage can be considered if the patient presents within one hour of ingestion. Inducing vomiting with syrup of ipecac is no longer recommended in any poisoning situation.
There is no antidote, and supportive care is the mainstay of further treatment for intoxication. Though sometimes referred to as a deliriant and while muscarine was first isolated from A. muscaria and as such is its namesake, muscimol does not have action, either as an agonist or antagonist, at the muscarinic acetylcholine receptor site, and therefore atropine or physostigmine as an antidote is not recommended. If a patient is delirious or agitated, this can usually be treated by reassurance and, if necessary, physical restraints. A benzodiazepine such as diazepam or lorazepam can be used to control combativeness, agitation, muscular overactivity, and seizures. Only small doses should be used, as they may worsen the respiratory depressant effects of muscimol. Recurrent vomiting is rare, but if present may lead to fluid and electrolyte imbalances; intravenous rehydration or electrolyte replacement may be required. Serious cases may develop loss of consciousness or coma, and may need intubation and artificial ventilation. Hemodialysis can remove the toxins, although this intervention is generally considered unnecessary. With modern medical treatment the prognosis is typically good following supportive treatment.


The wide range of psychoactive effects have been variously described as depressant, sedative-hypnotic, psychedelic, dissociative, or deliriant; paradoxical effects such as stimulation may occur however. Perceptual phenomena such as synesthesia, macropsia, and micropsia may occur; the latter two effects may occur either simultaneously or alternatingly, as part of Alice in Wonderland syndrome, collectively known as dysmetropsia, along with related distortions pelopsia and teleopsia. Some users report lucid dreaming under the influence of its hypnotic effects. Unlike Psilocybe cubensis, A. muscaria cannot be commercially cultivated, due to its mycorrhizal relationship with the roots of pine trees. However, following the outlawing of psilocybin mushrooms in the United Kingdom in 2006, the sale of the still legal A. muscaria began increasing.
Professor Marija Gimbutienė, a renowned Lithuanian historian, reported to R. Gordon Wasson on the use of this mushroom in Lithuania. In remote areas of Lithuania, Amanita muscaria has been consumed at wedding feasts, in which mushrooms were mixed with vodka. The professor also reported that the Lithuanians used to export A. muscaria to the Sami in the Far North for use in shamanic rituals. The Lithuanian festivities are the only report that Wasson received of ingestion of fly agaric for religious use in Eastern Europe.


In 1968, R. Gordon Wasson proposed that A. muscaria was the soma talked about in the Rigveda of India, a claim which received widespread publicity and popular support at the time. He noted that descriptions of Soma omitted any description of roots, stems or seeds, which suggested a mushroom, and used the adjective hári "dazzling" or "flaming" which the author interprets as meaning red. One line described men urinating Soma; this recalled the practice of recycling urine in Siberia. Soma is mentioned as coming "from the mountains", which Wasson interpreted as the mushroom having been brought in with the Aryan migrants from the north. Indian scholars Santosh Kumar Dash and Sachinanda Padhy pointed out that both eating of mushrooms and drinking of urine were proscribed, using as a source the Manusmṛti.
In 1971, Vedic scholar John Brough from Cambridge University rejected Wasson's theory and noted that the language was too vague to determine a description of Soma. In his 1976 survey, Hallucinogens and Culture, anthropologist Peter T. Furst evaluated the evidence for and against the identification of the fly agaric mushroom as the Vedic Soma, concluding cautiously in its favour. Kevin Feeney and Trent Austin compared the references in the Vedas with the filtering mechanisms in the preparation of Amanita muscaria and published findings supporting the proposal that fly-agaric mushrooms could be a likely candidate for the sacrament. Other proposed candidates include Psilocybe cubensis, Peganum harmala, and Ephedra.


The toxins in A. muscaria are water-soluble: parboiling A. muscaria fruit bodies can detoxify them and render them edible, although consumption of the mushroom as a food has never been widespread. The consumption of detoxified A. muscaria has been practiced in some parts of Europe (notably by Russian settlers in Siberia) since at least the 19th century, and likely earlier. The German physician and naturalist Georg Heinrich von Langsdorff wrote the earliest published account on how to detoxify this mushroom in 1823. In the late 19th century, the French physician Félix Archimède Pouchet was a populariser and advocate of A. muscaria consumption, comparing it to manioc, an important food source in tropical South America that must be detoxified before consumption.
Use of this mushroom as a food source also seems to have existed in North America. A classic description of this use of A. muscaria by an African-American mushroom seller in Washington, D.C., in the late 19th century is described by American botanist Frederick Vernon Coville. In this case, the mushroom, after parboiling, and soaking in vinegar, is made into a mushroom sauce for steak. It is also consumed as a food in parts of Japan. The most well-known current use as an edible mushroom is in Nagano Prefecture, Japan. There, it is primarily salted and pickled.
A 2008 paper by food historian William Rubel and mycologist David Arora gives a history of consumption of A. muscaria as a food and describes detoxification methods. They advocate that Amanita muscaria be described in field guides as an edible mushroom, though accompanied by a description on how to detoxify it. The authors state that the widespread descriptions in field guides of this mushroom as poisonous is a reflection of cultural bias, as several other popular edible species, notably morels, are toxic unless properly cooked.


The red-and-white spotted toadstool is a common image in many aspects of popular culture. Garden ornaments and children's picture books depicting gnomes and fairies, such as the Smurfs, often show fly agarics used as seats, or homes. Fly agarics have been featured in paintings since the Renaissance, albeit in a subtle manner. For instance, in Hieronymus Bosch's painting, The Garden of Earthly Delights, the mushroom can be seen on the left-hand panel of the work. In the Victorian era they became more visible, becoming the main topic of some fairy paintings. Two of the most famous uses of the mushroom are in the Mario franchise (specifically two of the Super Mushroom power-up items and the platforms in several stages which are based on a fly agaric), and the dancing mushroom sequence in the 1940 Disney film Fantasia.
An account of the journeys of Philip von Strahlenberg to Siberia and his descriptions of the use of the mukhomor there was published in English in 1736. The drinking of urine of those who had consumed the mushroom was commented on by Anglo-Irish writer Oliver Goldsmith in his widely read 1762 novel, Citizen of the World. The mushroom had been identified as the fly agaric by this time. Other authors recorded the distortions of the size of perceived objects while intoxicated by the fungus, including naturalist Mordecai Cubitt Cooke in his books The Seven Sisters of Sleep and A Plain and Easy Account of British Fungi. This observation is thought to have formed the basis of the effects of eating the mushroom in the 1865 popular story Alice's Adventures in Wonderland. A hallucinogenic "scarlet toadstool" from Lappland is featured as a plot element in Charles Kingsley's 1866 novel Hereward the Wake based on the medieval figure of the same name. Thomas Pynchon's 1973 novel Gravity's Rainbow describes the fungus as a "relative of the poisonous Destroying angel" and presents a detailed description of a character preparing a cookie bake mixture from harvested Amanita muscaria. Fly agaric shamanism is also explored in the 2003 novel Thursbitch by Alan Garner.


A. muscaria and A. pantherina are illegal to buy, sell, or possess in the Netherlands since December 2008. Possession of amounts larger than 0.5 g dried or 5 g fresh lead to a criminal charge.


The death cap is native to Europe, where it is widespread. It is found from the southern coastal regions of Scandinavia in the north, to Ireland in the west, east to Poland and western Russia, and south throughout the Balkans, in Greece, Italy, Spain, and Portugal in the Mediterranean basin, and in Morocco and Algeria in north Africa. In west Asia, it has been reported from forests of northern Iran. There are records from further east in Asia but these have yet to be confirmed as A. phalloides.
By the end of the 19th century, Charles Horton Peck had reported A. phalloides in North America. In 1918, samples from the eastern United States were identified as being a distinct though similar species, A. brunnescens, by George Francis Atkinson of Cornell University. By the 1970s, it had become clear that A. phalloides does occur in the United States, apparently having been introduced from Europe alongside chestnuts, with populations on the West and East Coasts. Although a 2006 historical review concluded the East Coast populations were inadvertently introduced, likely on the roots of other purposely imported plants such as chestnuts. The origins of the West Coast populations remained unclear, due to scant historical records. A 2009 genetic study provided strong evidence for the introduced status of the fungus on the west coast of North America. Observations of various collections of A. phalloides, from conifers rather than native forests, have led to the hypothesis that the species was introduced to North America multiple times. It is hypothesized that the various introduction involved led to multiple genotypes which are adapted to either oaks or conifers.
A. phalloides has been conveyed to new countries across the Southern Hemisphere with the importation of hardwoods and conifers. Introduced oaks appear to have been the vector to Australia and South America; populations under oaks have been recorded from Melbourne and Canberra (where two people died in January 2012, of four who were poisoned) and Adelaide, as well as Uruguay. It has been recorded under other introduced trees in Argentina and Chile.Pine plantations are associated with the fungus in Tanzania and South Africa, where it is also found under oaks and poplars. A number of deaths in India have been attributed to it.


It is ectomycorrhizally associated with several tree species and is symbiotic with them. In Europe, these include hardwood and, less frequently, conifer species. It appears most commonly under oaks, but also under beeches, chestnuts, horse-chestnuts, birches, filberts, hornbeams, pines, and spruces. In other areas, A. phalloides may also be associated with these trees or with only some species and not others. In coastal California, for example, A. phalloides is associated with coast live oak, but not with the various coastal pine species, such as Monterey pine. In countries where it has been introduced, it has been restricted to those exotic trees with which it would associate in its natural range. There is, however, evidence of A. phalloides associating with hemlock and with genera of the Myrtaceae: Eucalyptus in Tanzania and Algeria, and Leptospermum and Kunzea in New Zealand, suggesting that the species may have invasive potential. It may have also been anthropogenically introduced to the island of Cyprus, where it has been documented to fruit within Corylus avellana plantations.


Death caps have been reported to taste pleasant. This, coupled with the delay in the appearance of symptoms—during which time internal organs are being severely, sometimes irreparably, damaged—makes it particularly dangerous. Initially, symptoms are gastrointestinal in nature and include colicky abdominal pain, with watery diarrhea, nausea, and vomiting, which may lead to dehydration if left untreated, and, in severe cases, hypotension, tachycardia, hypoglycemia, and acid–base disturbances. These first symptoms resolve two to three days after the ingestion. A more serious deterioration signifying liver involvement may then occur—jaundice, diarrhea, delirium, seizures, and coma due to fulminant liver failure and attendant hepatic encephalopathy caused by the accumulation of normally liver-removed substance in the blood. Kidney failure (either secondary to severe hepatitis or caused by direct toxic kidney damage) and coagulopathy may appear during this stage. Life-threatening complications include increased intracranial pressure, intracranial bleeding, pancreatic inflammation, acute kidney failure, and cardiac arrest. Death generally occurs six to sixteen days after the poisoning.
Mushroom poisoning is more common in Europe than in North America. Up to the mid-20th century, the mortality rate was around 60–70%, but this has been greatly reduced with advances in medical care. A review of death cap poisoning throughout Europe from 1971 to 1980 found the overall mortality rate to be 22.4% (51.3% in children under ten and 16.5% in those older than ten). This has fallen further in more recent surveys to around 10–15%.


Consumption of the death cap is a medical emergency requiring hospitalization. The four main categories of therapy for poisoning are preliminary medical care, supportive measures, specific treatments, and liver transplantation.
Preliminary care consists of gastric decontamination with either activated carbon or gastric lavage; due to the delay between ingestion and the first symptoms of poisoning, it is common for patients to arrive for treatment many hours after ingestion, potentially reducing the efficacy of these interventions. Supportive measures are directed towards treating the dehydration which results from fluid loss during the gastrointestinal phase of intoxication and correction of metabolic acidosis, hypoglycemia, electrolyte imbalances, and impaired coagulation.
No definitive antidote is available, but some specific treatments have been shown to improve survivability. High-dose continuous intravenous penicillin G has been reported to be of benefit, though the exact mechanism is unknown, and trials with cephalosporins show promise. Some evidence indicates intravenous silibinin, an extract from the blessed milk thistle (Silybum marianum), may be beneficial in reducing the effects of death cap poisoning. A long-term clinical trial of intravenous silibinin began in the US in 2010. Silibinin prevents the uptake of amatoxins by liver cells, thereby protecting undamaged liver tissue; it also stimulates DNA-dependent RNA polymerases, leading to an increase in RNA synthesis. According to one report based on a treatment of 60 patients with silibinin, patients who started the drug within 96 hours of ingesting the mushroom and who still had intact kidney function all survived. As of February 2014 supporting research has not yet been published.
SLCO1B3 has been identified as the human hepatic uptake transporter for amatoxins; moreover, substrates and inhibitors of that protein—among others rifampicin, penicillin, silibinin, antamanide, paclitaxel, ciclosporin and prednisolone—may be useful for the treatment of human amatoxin poisoning.
N-Acetylcysteine has shown promise in combination with other therapies. Animal studies indicate the amatoxins deplete hepatic glutathione; N-acetylcysteine serves as a glutathione precursor and may therefore prevent reduced glutathione levels and subsequent liver damage. None of the antidotes used have undergone prospective, randomized clinical trials, and only anecdotal support is available. Silibinin and N-acetylcysteine appear to be the therapies with the most potential benefit. Repeated doses of activated carbon may be helpful by absorbing any toxins returned to the gastrointestinal tract following enterohepatic circulation. Other methods of enhancing the elimination of the toxins have been trialed; techniques such as hemodialysis, hemoperfusion, plasmapheresis, and peritoneal dialysis have occasionally yielded success, but overall do not appear to improve outcome.
In patients developing liver failure, a liver transplant is often the only option to prevent death. Liver transplants have become a well-established option in amatoxin poisoning. This is a complicated issue, however, as transplants themselves may have significant complications and mortality; patients require long-term immunosuppression to maintain the transplant. That being the case, the criteria have been reassessed, such as onset of symptoms, prothrombin time (PT), serum bilirubin, and presence of encephalopathy, for determining at what point a transplant becomes necessary for survival. Evidence suggests, although survival rates have improved with modern medical treatment, in patients with moderate to severe poisoning, up to half of those who did recover suffered permanent liver damage. A follow-up study has shown most survivors recover completely without any sequelae if treated within 36 hours of mushroom ingestion.


The spores are roughly spherical, 8–12 μm in diameter, thin-walled, and nonamyloid (that is, not absorbing iodine stain in Melzer's reagent). The pileipellis (cap cuticle) is composed of filamentous interwoven hyphae, 2–7 μm diameter, gelatinized. The spore-bearing cells, the basidia, are 36–52 by 4–13 μm, 4–sterigmate, without clamps. The volva is largely made of filamentous hyphae, 2–8 μm diameter, inflated cells broadly elliptic, elliptical, fusiform, to clavate, 40–85 by 10–35 μm, mostly terminal. The stem tissue is made up of filamentous hyphae with diameters of 2–6 μm; the inflated cells are terminal, club-shaped, longitudinally oriented, with dimensions of up to 289 by 31 μm.


Amaranthus palmeri is a species of edible flowering plant in the amaranth genus. It has several common names, including carelessweed, dioecious amaranth, Palmer's amaranth, Palmer amaranth, and Palmer's pigweed.
It is native to most of the southern half of North America. Populations in the eastern United States are probably naturalized. It has also been introduced to Europe, Australia, and other areas. The plant is fast-growing and highly competitive.


Pollen is most commonly spread by wind. The male produces the pollen and the female plant produces the seed. The wind carries the pollen from resistant male plants to female plants. In addition, the seed is spread by traditional means, such as harvesting, inadequate cleaning of equipment, and the spreading of contaminated materials, such as manure.
In 2014, North Dakota State University's "ND Weed Control Guide" selected Amaranthus palmeri, as "weed-of-the-year" to raise awareness about its "potentially devastating impact." In 2015, Palmer amaranth was chosen as "weed-of-the-year" for the second year in a row as a "proactive approach to prevent Palmer amaranth establishment in North Dakota." As alien, this species was first found in South Africa in March 2018 with further records in different regions of the country as well as in northern Botswana in March 2020. It is considered as naturalized weed which invades both ruderal and segetal (growing in cornfields) plant communities.


Amata phegea reaches a wingspan of 35–40 millimetres (1.4–1.6 in). Males are smaller than females and have thicker antennae. Wings are blueish black or greenish black with white spots and metallic sheen. The number and the size of spots are quite variable. Usually there are six white spots on the forewings and two or three spots on the hindwings. The body is quite long, with a yellow spot on the second segment of the abdomen. A further feature is the prominent yellow ring at the sixth segment of the abdomen. The black thread-like antennae have white tips. The caterpillars can reach a length of about 5 centimetres (2.0 in). They are gray black with thick dark brown, fluffy hairs that grow from small growths. The head is reddish brown.
Similar-looking moths include Amata ragazzii (Turati, 1917) and Zygaena ephialtes (Linnaeus, 1758). Z. ephialtes is in the family Zygaenidae and is unpalatable to birds. The nine-spotted moth imitates its appearance (Müllerian mimicry). Both moths are an example of aposematism.


The white-breasted waterhen (Amaurornis phoenicurus) is a waterbird of the rail and crake family, Rallidae, that is widely distributed across South and Southeast Asia. They are dark slaty birds with a clean white face, breast and belly. They are somewhat bolder than most other rails and are often seen stepping slowly with their tail cocked upright in open marshes or even drains near busy roads. They are largely crepuscular in activity and during the breeding season, just after the first rains, make loud and repetitive croaking calls.


Adult white-breasted waterhens have mainly dark grey upperparts and flanks, and a white face, neck and breast. The lower belly and undertail are cinnamon or white coloured. The body is flattened laterally to allow easier passage through the reeds or undergrowth. They have long toes, a short tail and a yellow bill and legs. Sexes are similar but females measure slightly smaller. Immature birds are much duller versions of the adults. The downy chicks are black, as with all rails.
Several subspecies are named for the populations that are widely distributed. The nominate subspecies is described from Sri Lanka but is often widened to include chinensis of mainland India and adjoining regions in Asia, west to Arabia and east nearly to Japan. The remaining subspecies are those from islands and include insularis of the Andaman and Nicobar Islands, midnicobaricus of the central Nicobars, leucocephala of Car Nicobar, maldivus of the Maldives, javanicus of Java and leucomelanus of Sulawesi and the Lesser Sundas.


These birds are usually seen singly or in pairs as they forage slowly along the edge of a waterbody mainly on the ground but sometimes clambering up low vegetation. The tail is held up and jerked as they walk. They probe with their bill in mud or shallow water, also picking up food by sight. They mainly eat insects (large numbers of beetles have been recorded), small fish (which are often carefully washed in water), aquatic invertebrates and grains or seeds such as those of Pithecolobium dulce. They may sometimes feed in deeper water in the manner of a moorhen.
The nesting season is mainly June to October but varies locally. They nest in a dry location on the ground in marsh vegetation, laying 6-7 eggs. Courtship involves bowing, billing and nibbling. The eggs hatch in about 19 days. Both sexes incubate the eggs and take care of the chicks. Chicks often dive underwater to escape predation. Adults are said to build a roost or brood nest where young chicks and the adults roost.
Many rails are very secretive, but white-breasted waterhens are often seen out in the open. They can be noisy especially at dawn and dusk, with loud croaky calls. The Andamans population insularis is said to make duck like quack calls.


The berylline hummingbird (Saucerottia beryllina) is a medium-sized hummingbird. It is 8–10 cm long, and weighs 4-5 g.
Adults are colored predominantly metallic olive green with a rusty gray lower belly.  The tail and primary wings are rufous in color and slightly forked.  The underwing is also rufous.  The bill of the male is straight and very slender.  It is very dark red in coloration, almost black.  The female is less colorful than the male.
The breeding habitat is in forests and thickets of western  Mexico to central Honduras in Central America.  It regularly strays to southeasternmost Arizona in the United States where it occasionally breeds–(the Madrean sky islands).  The female builds a nest in a protected location in a shrub or tree.  Females lay two white eggs.  This hummingbird is essentially non-migratory.
These birds feed on nectar from flowers and flowering trees using a long extendable tongue or catch insects on the wing.
This species was formerly placed in the genus Amazilia. A molecular phylogenetic study published in 2014 found that the genus Amazilia was polyphyletic. In the revised classification to create monophyletic genera, the berylline hummingbird was moved to the resurrected genus Saucerottia.


The azure-crowned hummingbird (Saucerottia cyanocephala) is a species of hummingbird in the family Trochilidae.
It is found in Belize, El Salvador, Guatemala, Honduras, Mexico, and Nicaragua.
Its natural habitat is subtropical or tropical moist montane forest. The males have a metallic blue crown, while the females are identifiable by a more dull blue or greenish crown. It forages on arthropods (often searching bark and clusters of pine needle) as well as nectar from flowers. The species seems to be territorial based on how available resources are, and like most hummingbirds is likely polygamous. Its nests are generally cup shaped used from local resources, but in an urban setting the species has been known to even use objects such as telephone wires in its construction.
This species was formerly placed in the genus Amazilia. A molecular phylogenetic study published in 2014 found that the genus Amazilia was polyphyletic. In the revised classification to create monophyletic genera, the azure-crowned hummingbird was moved to the resurrected genus Saucerottia.


The cinnamon hummingbird is 9.5 to 11.5 cm (3.7 to 4.5 in) long and on average weighs about 5 to 5.5 g (0.18 to 0.19 oz). Adults of the nominate subspecies A. r. rutila have metallic bronze green upperparts and cinnamon to cinnamon rufous underparts that are paler on the chin and upper throat. The tail is deep cinnamon rufous to rufous chestnut; the feathers have dark metallic bronze tips and the outermost have dark metallic bronze outer edges. The wings are a dark brownish slate. Males' bills are red with a black tip and females' mostly black with red at the base. Juveniles are similar to adults but have rufous edges to the face, crown, and rump feathers and an all black bill.
A. r. diluta is similar to the nominate, with slightly less intense green upperparts and paler and pinker underparts. A. r. corallirostris is also similar to the nominate but overall its colors are richer and deeper. A. r. graysoni is significantly larger and darker than the nominate but otherwise similar.


The subspecies of cinnamon hummingbird are found thus:
A. r. diluta, the northwestern Mexican states of Sinaloa and Nayarit
A. r. graysoni, Isla María Madre in Islas Marías off the coast of western Mexico
A. r. rutila, from Jalisco in western Mexico south through El Salvador and western Honduras and Nicaragua into northwestern Costa Rica.
A. r. corallirostris, from Chiapas in Mexico south to El Salvador
The populations in Mexico's Yucatán state, northeastern Honduras, Nicaragua, and Costa Rica are usually attributed to A. r. rutila but have sometimes been considered to be part of A. r. corallirostris.
The cinnamon hummingbird inhabits primary and secondary deciduous and semi-deciduous forests and thorn forest. It ranges from sea level to about 1,600 m (5,200 ft) of elevation.


The cinnamon hummingbird usually forages from the understory to the mid-story, but also will visit taller flowering trees. It feeds on nectar from a very wide variety of flowering plants and also eats insects. It is territorial and defends feeding sites from intrusion by other hummingbirds, bees, and butterflies.


The cinnamon hummingbird's breeding season varies throughout its range; every month is represented somewhere. Its nest is a cup made of plant material and spider web placed on a horizontal branch. Three nests in western Mexico had a small platform of wood pieces under the cup. The cup was made of kapok seed fibers with grass, bits of wood, and lichens on the outside. All three were in semi-deciduous forest. The clutch size is two eggs, but little more is known about the species' breeding phenology.


The cinnamon hummingbird's song is "varied, high, thin, slightly squeaky chips, si ch chi-chit or tsi si si-si-sit, or chi chi-chi chi chi, etc." Its call has been described as "a buzzy, scratchy tzip" and "a hard to sharp chik".


The rufous-tailed hummingbird (Amazilia tzacatl) is a medium-sized hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is found from east-central Mexico through Central America and Colombia into Ecuador and Venezuela.


The rufous-tailed hummingbird is 9 to 11 cm (3.5 to 4.3 in) long and weighs approximately 5 g (0.18 oz). The adult male of the nominate subspecies has a green head and upperparts except for chestnut-brown lores and uppertail coverts. The tail is also mostly chestnut-brown, giving the species its English name; the feathers' outer webs and tips are bronze green. The throat, upper breast, and sides are green; the throat feathers sometimes have thin white edges giving a scalloped effect. The lower breast is gray, the belly white, and the undertail coverts chestnut-brown. The adult female's lower breast is a paler gray than the male's and the scalloping on the throat is more pronounced. Juveniles have a cinnamon wash to the lower breast and sides and the feathers of the lower back and rump have narrow cinnamon tips. The outer half of the bill's maxilla is black and the inner half red; the mandible is red with a black tip.
A. t. handleyi has the same color pattern as the nominate but is significantly larger and darker. A. t. fuscicaudata is smaller than the nominate and has a shorter and stouter bill. A. t. jucunda's maxilla is pinkish brown rather than black; its belly is a darker gray than the nominate's and the bronze green on the tail is narrower. A. t. brehmi is similar to jucunda and fuscicaudata but has longer wings and tail. It has a longer bill than fuscicaudata and reduced green on the tail like jucunda.


The subspecies of the rufous-tailed hummingbird are found thus:
A. t. tzacatl, from the eastern Mexican states of Veracruz and Oaxaca south through Belize, Guatemala, Honduras, Nicaragua, and Costa Rica into most of Panama (It apparently skips El Salvador.)
A. t. handleyi, Isla Escudo de Veraguas off the Caribbean coast of northwestern Panama
A. t. fuscicaudata, the Cauca River and Magdalena River valleys of northern and western Colombia east into western Venezuela's Lara and Táchira states
A. t. brehmi, the upper Güiza River in Colombia's Nariño Department
A. t. jucunda, from Chocó Department in western Colombia south through western Ecuador to Loja Province
The South American Classification Committee (SACC) of the American Ornithological Society extends the range of A. t. jucunda into Peru.
The rufous-tailed hummingbird inhabits open, non-forested, landscapes such as clearings, gardens, and the edges of forest. It is also found in low, young, brushy, secondary forest. It frequently comes to feeders. In elevation the rufous-tailed hummingbird ranges from sea level to 1,200 m (3,900 ft) in Mexico, to 1,850 m (6,100 ft) in Costa Rica, 1,800 m (5,900 ft) in Colombia, and 1,700 m (5,600 ft) in Venezuela. It is found as high as 2,500 m (8,200 ft) in Ecuador but that elevation is thought be local or seasonal.


Like most hummingbirds, the rufous-tailed feeds on nectar and small insects. It is common at sugar water feeders and often seen in coffee and banana plantations. It is extremely territorial and aggressive at feeding sites such as flower patches and feeders, from which it chases other hummingbirds and large insects.


The rufous-tailed hummingbird is polygynous. Though it is aggressive while feeding, the species sometimes nests in loose colonies. Its breeding season varies widely across its range, but is within the February to November span. The female is entirely responsible for nest building, incubation of eggs, and care of nestlings. She lays two white eggs in a compact cup nest constructed from plant fibers, leaves, and spiderwebs covered with lichens and mosses. It is typically placed up to 6 m (20 ft) high on a thin horizontal twig. Incubation takes 15 to 19 days, and fledging another 18 to 22 days.


The IUCN has assessed the rufous-tailed hummingbird as being of Least Concern. It has a very large range and a population estimated at more than five million mature individuals, though that number is thought to be decreasing. The species might actually benefit from human activity, as deforestation provides open spaces. The species frequents coffee and banana plantations and readily comes to feeders.


The buff-bellied hummingbird (Amazilia yucatanensis) is a medium-sized hummingbird. It is 10–11 cm (3.9–4.3 in) long and has a mass of 4–5 g (0.14–0.18 oz).
Adults are a metallic olive green above and buffy in the lower breast. The tail and primary wings are rufous in colour and slightly forked. The underwing is white. The bill of the male is straight and very slender. It is red in colouration with a darker tip. The throat is a metallic golden green. The female has a dark upper bill, and is less colourful than the male.
Their breeding habitat is forests and thickets that extend from the lower Rio Grande Valley of southernmost Texas in the United States through the Yucatán Peninsula of eastern Mexico, ending in northern Belize and northwestern Guatemala in Central America. It prefers pine-oak forests, semi-arid scrub and thickets along watercourses. The female builds a nest in a protected location such as a shrub or tree. Both males and females of any age aggressively defend feeding locations within his or her territory. Females lay two white eggs.
This hummingbird is partially migratory. The buff-bellied hummingbird winters in small numbers along the Gulf Coast of the United States from Texas to the Florida panhandle.
These birds feed on nectar from flowers and flowering trees using a long extendable tongue and catch insects on the wing.


The plumage of an adult lilac-crowned amazon is primarily green with yellowish underparts and black edging. The forehead is a maroon color with a light blue-lilac neck, nape, and crown. The cheeks and ear coverts are a greenish yellow that lacks the edging that is present in most of the plumage. The primary feathers are dark blue with the secondary feathers being green while being tipped with the same dark blue coloring. Furthermore, the initial five secondary feathers have a bright red speculum on the edge of the feathers. The wing coverts, underside of the flight feathers, and the tail are green while the tail is tipped with a yellowish coloring similar to that of the cheeks and ear coverts. Their beak, orbital rings, and legs are a palebrown-grey coloring. The irides of adult lilac-crowned parrots are amber colored.
Juvenile lilac-crowned amazons are visually similar to their adult forms except for minor differences. One difference is that the iris of juveniles are a dark brown as opposed to the amber coloring that is found in adults. The other major difference is that there less maroon colored feathers on the forehead of juveniles. After about one year juveniles begin to acquire these adult features.


The lilac-crowned amazon's endemic range spans along the pacific coast of Mexico, beginning in southeastern Sonora and southwestern Chihuahua down to southern Oaxaca. In Sinaloa and northern Nayarit the geographic range of the lilac-crowned parrot is above 375 meters of elevation and does not reach sea level until southern Nayarit, where it remains so through Jalisco and Oaxaca.
The lilac-crowned amazon's natural habitat in Mexico is often threatened. Decline in population size has been recorded in almost all of its natural habitat locations. Based on collection of data and resident accounts, Amazona finschi population range has decreased by 20% due to habitat loss.
An increasingly growing population of approximately 100 individuals is found in Southern California especially in the San Gabriel Valley and Orange Country. This increase could also be attributed to a more reliable source of measurement of population than in past years. These populations often are found in residential areas and occasionally in nesting groups with red-crowned parrots in native conifer forests or non-native captive plants.


The Brazilian teal was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with all the other ducks, swans and geese in the genus Anas and coined the binomial name Anas brasiliensis.  Gmelin based his description on the Mareca alia species (the second Mareca) that was described in 1648 by the German naturalist Georg Marcgrave in his Historia Naturalis Brasiliae. The Brazilian teal is now the only species placed in the genus Amazonetta that was introduced by the German zoologist Hans von Boetticher in 1929.
It was formerly considered a perching duck, but more recent analyses indicate that it belongs to a clade of South American dabbling ducks which also includes the crested duck, the bronze-winged duck, and possibly the steamer ducks.
Two subspecies are recognised:
A. b. brasiliensis (Gmelin, 1789) – the nominate race, found in Brazil, Suriname, Guyana, French Guiana, central Venezuela, eastern Colombia, and northeastern Peru
A. b. ipecutiri (Vieillot, 1816) – found in Brazil, northern Argentina, eastern Bolivia, Uruguay, and Paraguay


They can be found throughout eastern South America, from central Brazil, to Uruguay, to northern and eastern Argentina, Paraguay, central Venezuela, northeastern Peru, Suriname, Guyana, French Guiana, eastern Bolivia, and eastern Colombia. Their preferred habitat is a body of freshwater away from the coast with dense vegetation nearby.


Brazilian teal live in pairs or in small groups of up to twenty birds. Both parents look after their hatchlings. They eat seeds, fruits, roots and insect, while ducklings eat only insects.


The marine iguana (Amblyrhynchus cristatus), also known as the sea iguana, saltwater iguana, or Galápagos marine iguana, is a species of iguana found only on the Galápagos Islands (Ecuador). Unique among modern lizards, it is a marine reptile that has the ability to forage in the sea for algae, which makes up almost all of its diet. Marine iguanas are the only extant lizard that spends time in a marine environment. Large males are able to dive to find this food source, while females and smaller males feed during low tide in the intertidal zone. They mainly live in colonies on rocky shores where they bask after visiting the relatively cold water or intertidal zone, but can also be seen in marshes, mangrove swamps and beaches. Large males defend territories for a short period, but smaller males have other breeding strategies. After mating, the female digs a nest hole in the soil where she lays her eggs, leaving them to hatch on their own a few months later.
Marine iguanas vary in appearance between the different islands and several subspecies are recognized. Although relatively large numbers remain and it is locally abundant, this protected species is considered threatened, primarily from El Niño cycles, introduced predators and chance events like oil spills.


Researchers theorize that land iguanas (genus Conolophus) and marine iguanas evolved from a common ancestor since arriving on the islands from Central or South America, presumably by rafting. The land and marine iguanas of the Galápagos form a clade, the nearest relatives of which are the Ctenosaura iguanas of Mexico and Central America. Based on a study that relied on mtDNA, the marine iguana diverged from land iguanas some 8–10 million years ago, which is older than any of the extant Galápagos islands. It has therefore traditionally been thought that the ancestral species inhabited parts of the volcanic archipelago that are now submerged. A more recent study that included both mtDNA and nDNA indicates that the two split about 4.5 million years ago, which is near the age of the oldest extant Galápagos islands (Española and San Cristóbal).
The marine iguana and Galápagos land iguana remain mutually fertile in spite of being separated by millions of years and assigned to distinct genera. They have been known to hybridize where their ranges overlap, resulting in the so-called hybrid iguana. This is very rare and has only been documented a few times on South Plaza, a tiny island where the usually separated breeding territories and seasons of the two species overlap. The hybrids have intermediate features, stay on land and are infertile.
The different marine iguana populations fall into three main clades: western islands, northeastern islands and southeastern islands. These can be further divided, each subclade generally matching marine iguanas from one or two primary island, except on San Cristóbal where there are two subclades (a northeastern and a southwestern). However, even the oldest divergence between marine iguana populations is quite recent; no more than 230,000 years and likely less than 50,000 years. On occasion one makes it to another island than its home island, resulting in hybridization between different marine iguana populations. There is one confirmed record of a marine iguana outside the Galápagos Islands; in 2014 an individual appeared on Isla de la Plata near the Ecuadorian mainland.


Seven or eight subspecies of the marine iguana, listed alphabetically, have traditionally been recognized:
A. c. albemarlensis Eibl-Eibesfeldt, 1962 – Isabela Island
A. c. ater Gray, 1831 (not always recognized) – Pinzón Island
A. c. cristatus Bell, 1825 – Fernandina Island
A. c. hassi Eibl-Eibesfeldt, 1962 – Santa Cruz Island
A. c. mertensi Eibl-Eibesfeldt, 1962 – San Cristóbal and Santiago Islands
A. c. nanus Garman, 1892 – Genovesa Island
A. c. sielmanni Eibl-Eibesfeldt, 1962 – Pinta Island
A. c. venustissimus Eibl-Eibesfeldt, 1956 – Española Island and adjacent tiny Gardener Island
In 2017, the first comprehensive taxonomic review of the species in more than 50 years came to another result based on morphological and genetic evidence, including recognizing five new subspecies (three of these are small-island populations that were not previously assigned to any subspecies):
A. c. cristatus Bell, 1825 (albermarlensis and ater are junior synonyms) – Isabela Island and Fernandina Island
A. c. godzilla Miralles et al., 2017 – northeastern part of San Cristóbal Island
A. c. hassi Eibl-Eibesfeldt, 1962 – Santa Cruz Island and smaller adjacent islands, such as Baltra Island
A. c. hayampi Miralles et al., 2017 – Marchena Island
A. c. jeffreysi Miralles et al., 2017 – Wolf Island, Darwin Island and Roca Redonda
A. c. mertensi Eibl-Eibesfeldt, 1962 – southwestern part of San Cristóbal Island
A. c. nanus Garman, 1892 – Genovesa Island
A. c. sielmanni Eibl-Eibesfeldt, 1962 – Pinta Island
A. c. trillmichi Miralles et al., 2017 – Santa Fé Island
A. c. venustissimus Eibl-Eibesfeldt, 1956 – Española Island (including adjacent tiny Gardener Island) and Floreana Island
A. c. wikelskii Miralles et al., 2017 – Santiago Island and smaller adjacent islands, such as Rábida Island


Early visitors to the Galápagos Islands considered the marine iguanas ugly and disgusting. In 1798, captain James Colnett of the British Royal Navy wrote:
 The [i]guanas are small, and of a sooty black, which, if possible, heightens their native ugliness. Indeed, so disgusting is their appearance, that no one on board could be prevailed on, to take them as food.
On his visit to the islands in 1835, despite making extensive observations on the creatures, Charles Darwin was revolted by the animals' appearance, writing:
The black Lava rocks on the beach are frequented by large (2–3 ft [0.6–0.9 m]),  most disgusting, clumsy Lizards. They are as black as the porous rocks over which they crawl & seek their prey from the Sea. Somebody calls them 'imps of darkness'. They assuredly well-become the land they inhabit.
Marine iguanas have a thickset body and relatively short, robust limbs. Adults have a row of spines extending from the nape, along the back to the tail. Males have longer spines, and larger bony plates on the top of their head than females. There are some differences in the spines depending on the island and they are most elaborate on Fernandina (subspecies cristatus). The scales on the top of the head of the marine iguana are quite conical and pointed. Although less extreme, the same can be seen in the Galápagos land iguanas (genus Conolophus), while these scales at most are slightly domed in other iguanas. Overall the skeleton of the marine iguana shows many similarities with the chuckwallas (genus Sauromalus), but this is an example of homoplasy, as the two are not closely related.
Marine iguanas are not always black; the young have a lighter coloured dorsal stripe, and some adult specimens are grey. Dark tones allow the lizards to rapidly absorb heat to minimize the period of lethargy after emerging from the water. The marine iguana lacks agility on land but is a graceful swimmer. Its laterally flattened tail provides propulsion and the row of spines along the back provide stability, while its long, sharp claws allow it to hold onto rocks in strong currents. Adult males vary in colour with the season, becoming brighter when breeding. There are also major differences in the colour of the adult males depending on the subspecies. Males of the relatively small southern islands of Española, Floreana and Santa Fé (subspecies venustissimus and trillmichi) are the most colourful, with bright pinkish-red and turquoise markings. In comparison, those of the relatively small northern islands of Genovesa, Marchena, Pinta, Wolf and Darwin (jeffreysi, hayampi, sielmanni and nanus) are almost all blackish without contrasting markings. Other subspecies tend to resemble duller versions of venustissimus and trillmichi, or are blackish with markings in pale yellowish, ochre, greenish or grey (sooty to near white). It is suspected that the exact algal diet of each population plays a role in their colour. Females show much less variation between the islands and are typically dark with less contrasting colours than the males. In most places, females do not change colour conspicuously between the breeding and non-breeding season, but at least on Española (subspecies venustissimus) they do assume relatively bright male-like colours when nesting, which is possibly related to their need of defending the nest from other females on an island with few suitable sites.


Female marine iguanas reach sexual maturity at the age of 3–5 years, while males reach sexual maturity at the age of 6–8 years. Sexual maturity is marked by the first steep and abrupt decline in bone growth cycle thickness. Marine iguanas can reach an age of up to 60 years, but average is 12 years or less.
Reproduction in the marine iguana begins during the last part of the cold and dry season, with breeding from December to March and nesting from January to April. The exact timing varies with location, depending on algal growth and the nutrient-rich Cromwell Current. It occurs earliest on islands like Fernandina, Isabela, Santa Fé and Genovesa, and latest on islands like Española. An adult marine iguana, whether male or female, will typically breed every other year, but if there is plenty of food a female may breed each year.
Marine iguanas live in coastal colonies that typically range from 20 to 500 animals, but sometimes more than 1,000. Their bodies often touch each other, but there are no social interactions like grooming, as commonly seen in social mammals and birds. Females are always highly gregarious and males are gregarious outside the breeding season. However, large males defend territories for up to three months during the breeding season, and in this period they sometimes fight other males. A territory can be up to almost 40 m² (430 sq ft), but is usually less than half that size, and can be as small as 1 m² (11 sq ft). A territory is often delimited by geographic features, like boulders or crevices. The territories tend to occur in clusters with several located adjacent to each other, forming a lek, but they can occur singly. Medium-sized males roam areas near the territories of large males or walk along beaches looking for females, while small "sneaky" males may enter the territories of large males. To threaten another male, a male will bob his head, walk on stiff legs, raise the spiny crest along the back and open the mouth to reveal the reddish interior. In most cases the suitor will turn away, but if he responds with the same behavior a fight ensues. During fights they typically do not bite each other, instead thrusting their heads together in an attempt to push the other away. The bony plates on the top of their heads are especially suited for interlocking. Fights between males may last for hours, and are often interrupted by periodic breaks. Once a winner has been established through the headbutting, the loser assumes a submissive position and retreats. In general fights between males are harmless and highly ritualized, but on occasion they will bite and injure each other.
Males are primarily selected by females on the basis of their body size. Females display a stronger preference for mating with bigger males. It is precisely because of body size that reproductive performance increases and "is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males." Other factors involved in the female's choice of partner are the display frequency by a male (especially head-bobbing) and the quality of a male's territory. Females prefer male territories that include or are near their own resting places, which they choose based on proximity to the sea, access to shade, low midday temperature and the possibility of sunbathing in the afternoon. Males with territories that are near the center of the lek tend to have a greater mating success than males with peripheral territories, but the size of a territory does not affect mating success. Large territorial males that frequently display also emit higher levels of certain acidic compounds (including 11-Eicosenoic acid) from their femoral pores, which may function as pheromones that enhance their chance of attracting females. Females can move freely between different territories, but receive less harassment from opportunistic non-territorial males when inside another male's territory. Medium-sized males attempt to mate by force and small males by stealth and force, but they have a low mating success rate compared to the large males that maintain a territory. During courtship display, a territorial male nods at the female, may open his mouth, and performs a slow sideways walk towards her. If she accepts, the male will mount her while holding her by the neck. A mating lasts no more than 20 minutes, typically 3 to 4 minutes, but it is comparatively rapid in the small "sneaky" males, which easily are overlooked because their size, general morphology and colours are similar to those of a female. This rapid mating is necessary because large males will chase them out of their territory as soon as they are discovered. During each breeding season, a male will mate with many females if given the chance, but the female only mates once. Once a female has mated, she rejects other suitors by nodding her head at them.
Roughly one month after copulation, the female lays between one and six eggs, typically two or three. The leathery white eggs measure about 9 cm × 4.5 cm (3.5 in × 1.8 in) and weigh 80–120 g (2.8–4.2 oz). This is large for an iguana, and altogether the eggs may weigh up to one-quarter the weight of the female. The nest sites can be as much as 2 km (1.2 mi) inland, but typically are much closer to the coast. They are occasionally as little as 20 m (66 ft) inland, although they have to be above the high tide water mark. The nest is 30–80 cm (12–31 in) deep and dug in sand or volcanic ash by the female. On islands where there are few suitable sites and digging is difficult due to a relatively hard soil and many rocks, the female guards the nest for several days after the eggs have been buried, ensuring that they are not dug up by other nesting females. As in males defending their territory from other males, females defending their nest site from other females begin with a threat display. If this fails to scare the opponent away, the fights between females involve much biting and are less ritualized than the territorial fights between males. Where there are more suitable sites and the soil is loose, females are less likely to fight for a location and do not guard their nest after the eggs have been buried. The eggs hatch after about three to four months. The hatchlings are 9.5–13 cm (3.7–5.1 in) in snout-to-vent length, and weigh 40–70 g (1.4–2.5 oz). As soon as they emerge from the nest they run for cover, and begin their trip to locations that provides optimum conditions for feeding, temperature regulation and shelter. Some hatchlings have been recorded moving as far as 3 km (1.9 mi) in two days.


The marine iguana forages almost exclusively on red and green algae in the inter- and subtidal zones. At least 10 genera of algae are regularly consumed, including the red algae Centroceras, Gelidium, Grateloupia, Hypnea, Polysiphonia and Pterocladiella. In some populations the green algae Ulva dominates the diet. The algal diet varies depending on algal abundance, individual preferences, foraging behaviour, season and exact island of feeding. Some species with chemical deterrents, such as Bifurcaria, Laurencia and Ochtodes, are actively avoided, but otherwise algal food choice mainly depends on energy content and digestibility. On Santa Cruz Island, 4–5 red algal species are the food of choice. During neap low tides, however, the usually avoided green algae Ulva lobata is eaten more often since the preferred red algae is not easily available. Brown algae have occasionally also been recorded in their diet, but marine iguanas are unable to easily digest these and will starve if it is the only type present. A 1 kg (2.2 lb) marine iguana typically eats about 8.6 g (0.30 oz) dry weight or 37.4 g (1.32 oz) fresh weight of algae per day. At Punta Espinoza on northeastern Fernandina Island it has been estimated that the almost 1,900 marine iguanas eat about 27–29 tonnes (fresh weight) of algae per year, a rate of consumption that is counterbalanced by the very high growth rate of the algae. They may feed on crustaceans, insects, and sea lion feces and afterbirth on rare occasions. The population on North Seymour Island will supplement their diet with land plants, primarily Batis maritima, or other coastal succulents like Sesuvium portulacastrum. These North Seymour iguanas have a higher survival rate during periods where their normal algal food is reduced. However, the hindgut of marine iguanas is specially adapted to algae feeding, likely restricting the possibility of efficiently switching to other plant types. The algae are digested with the help of endosymbiotic bacteria in their gut.
In the first months after hatching, the juveniles mainly feed on feces from larger marine iguanas, gaining the bacteria needed for digesting algae. It has been suggested that young iguanas up to about two years old are unable to swim, but studies have shown that even newly hatched marine iguanas are good swimmers; they just strongly try to avoid entering the water. At about 1–2 years old the young may voluntarily swim in shallow water and tide pools, but they do not dive.
Marine iguanas can dive as deep as 30 m (98 ft), and can spend up to one hour underwater. When diving to 7 m (23 ft) or deeper, they regularly remain submerged from 15 to more than 30 minutes. Most dives are much shorter in duration and shallower than 5 m (16 ft). Individuals foraging near-shore, often less than 1 m (3.3 ft) deep, typically only spend about 3 minutes underwater. Only 5% of marine iguanas dive for algae offshore and these individuals are the large males. The minimum size of these divers vary with island and subspecies, ranging from 0.6 kg (1.3 lb) on Genovesa Island (A. c. nanus) to 3 kg (6.6 lb) on Fernandina Island (A. c. cristatus). They are slow swimmers, averaging just 0.45 metres per second (1.5 ft/s). The highest recorded speed is only about twice that figure and this can typically only be sustained in bursts that last less than a minute. Most females and smaller males feed on exposed algae in the intertidal zone during low tide, retreating once the water returns and starts washing over them. They often scurry back-and-forth repeatedly, running to a patch of algae to take a few bites and then return fast to higher ground to avoid incoming waves. The separation in feeding behavior is advantageous because the large offshore feeding males experience less competition for food from smaller males and females. A few individuals of intermediate size may use both feeding strategies. In general, each marine iguana has a specific feeding site it returns to day after day. Most feed daily, but large offshore feeding males often only every second or third day. During bad weather with high waves marine iguanas do not feed, sometimes for more than a week. Large males often do not feed for several weeks when maintaining a breeding territory, resulting in them losing up to about one-quarter of their weight. It takes many months for them to return to their original weight. In captivity, individuals have remained strong and active even after fasting for as much as 100 days.
Foraging behavior changes in accordance to the seasons and foraging efficiency increases with temperature.  These environmental changes and the ensuing occasional food unavailability have caused marine iguanas to evolve by acquiring efficient methods of foraging in order to maximize their energy intake and body size. During an El Niño cycle in which food diminished for two years, some were found to decrease their length by as much as 20%.  When food supply returned to normal, iguana size followed suit.  It is speculated that the bones of the iguana actually shorten as shrinkage of connective tissue could only account for a 10% change in length.
Marine iguanas have several adaptions that aid their feeding. Their flattened tail is the primary means of propulsion in the water. When on the surface, they may use their legs for maintaining balance. Although their partially webbed feet often are mentioned, this webbing is very marginal and no greater in extent than in the green iguana, a species that also shares the flattened tail. Marine iguanas have powerful limbs with long, sharp claws for climbing, holding onto rocks and pulling themselves forward when at the sea bottom (adding to the propulsion provided by the tail). They are buoyant and float to the ocean surface if they are not actively swimming or holding on to rocks underwater. However, they have unusually compact (osteosclerose) limb bones compared to the land iguana, especially those from the front limbs, providing ballast to help with diving.
Other adaptions in marine iguanas are blunt heads ("flat noses") and sharp teeth allowing them to easier graze algae off rocks. Together with a few Ctenosaurus species, it is the only iguana that never has more than three tips (tricuspid) on each tooth. Uniquely, the side-tips on the marine iguana's teeth are quite large, only somewhat smaller than the central tip. It also appears to replace its teeth at a higher rate than other iguanas. As a sea reptile, much salt is ingested. The salt is filtered from their blood and then excreted by specialised cranial exocrine glands at the nostrils, expelled from the body in a process much like sneezing. The marine iguana's cranium has an unusually large nasal cavity compared to other iguanas, which is necessary to accommodate the large salt glands. The head may appear white from encrusted salt.


Marine iguanas have mutualistic and commensal relationships with several other animals. Lava lizards may scurry over marine iguanas when hunting flies, and Darwin's finches, mockingbirds and Sally lightfoot crabs sometimes feed on mites and ticks that they pick off their skin. Marine iguanas typically ignore these visits. When underwater, they are often cleaned by fish, like Pacific sergeant majors that pick off moulting skin. Although there are no apparent benefits to either species, marine iguanas commonly live close together with the much larger Galápagos sea lions. The two species generally ignore each other and an iguana may even crawl over the body of a sea lion.


Marine iguanas are unique as they are marine reptiles that forage on inter- and subtidal algae almost exclusively. They forage in the relatively cold waters around the Galápagos Islands, which typically are between 11 and 23 °C (52–73 °F) at the sea surface. As their preferred body temperature is from 35 to 39 °C (95–102 °F) and the temperature declines throughout a foraging trip to the sea, sometimes by as much as 10 °C (18 °F), the marine iguana has several behavioral adaptations for thermoregulation. At cold temperatures their muscles are less efficient, but their relatively high temperature preference is also related to the optimal temperature for digesting the algal food in their gut.
As an ectothermic animal, the marine iguana can spend only a limited time in cold water diving for algae. Afterwards it basks in the sun to warm up. Until it can do so it is unable to move effectively, making it vulnerable to predation. However, this is counteracted by their highly aggressive nature consisting of biting and expansive bluffs when in this disadvantageous state. Their dark shade aids in heat reabsorption. In colder periods with cloudy weather and much wind, juveniles will stay in the lee of rocks, still gaining the heat from the sun. Adults may move inland to low-lying sites with less wind because of bushes and lava ridges but still exposed to direct sun. When in the water and their temperature is falling, their blood circulation is reduced because of a low heart rate of about 30 beats per minute, allowing them to better conserve their warmth. When on land and heating up, the higher heart rate of about 100 beats per minute aids in spreading the heat throughout the body. To conserve heat during the night, they often sleep closely together in groups that may number up to 50 individuals, while others sleep alone below plants or in crevices.
In general, the time of each foraging trip is directly related to the water temperature; the colder the water the shorter the foraging trip. Additionally, marine iguanas that forage in or near the intertidal zone prefer to do so during low tides, allowing them to remain on land (on rocks exposed by the tide) or return to land faster. Individuals that forage further from the shore by diving are large males, which mainly feed during the hot midday (although it may occur from late morning to early evening), are less affected by the cool water because of their body size and are more efficient swimmers.
Under the tropical sun, overheating can also be a problem. To avoid this, they pant, and adopt a posture where they face the sun and lift their body up, thereby exposing as little as possible of their body to direct sun and allowing cooling air to pass underneath.


The marine iguana has a relatively small range and is currently considered vulnerable by the IUCN. Most subpopulations have the same IUCN rating, but those of San Cristóbal, Santiago and Genovesa Islands are considered endangered.
On some shorelines they can be very numerous, with densities as high as 8,000 per kilometer (almost 13,000 per mile), and their biomass compared to the area they occupy may surpass that of any known reptile. However, their distribution is patchy, and colonies are generally found within 100 m (330 ft) of the ocean, naturally limiting their range. The total population for the entire archipelago is estimated to be 200,000–300,000 individuals, although this number is labelled with considerable uncertainty. Most subpopulations have not been surveyed in detail because their lifestyle and habitat make it difficult to survey with a high level of accuracy. By far the largest subpopulation—likely including around 2⁄5 of all marine iguanas—lives on Fernandina Island, but estimates vary greatly from 15,000 to 120,000 individuals. In contrast, the maximum size of the subpopulations on the islands of San Cristóbal, Darwin and Pinzon is estimated to be 400, 800 and 900, respectively. It is estimated that Marchena Island has 4,000–10,000 marine iguanas, Rabida Island has 1,000–2,000 and Santa Fé Island has 15,000–30,000. Although individuals may on occasion be transferred between islands by ocean currents, marine iguanas are unable to swim between all but the nearest islands in the archipelago because of their slow speed and limited stamina in the relatively cold water.
The periodic El Niño events reduce the cold water needed for algae to grow and this can drastically reduce the marine iguana population, on some islands with as much as 90%. Population recoveries after El Niños are fast; even when reduced by 30–50%, the population is generally able to recover within four years. However, recoveries can be partially impeded by the invasive brown algae Giffordia mitchelliae. When their food algae (red and green algae) disappears during El Niños, the areas may be taken over by this brown algae, causing starvation among the marine iguanas. With global warming, it is expected that El Niño events will be stronger and occur more frequently.
Introduced predators, to which they have little or no protection, include animals such as pigs, dogs, cats and rats. Dogs may take adult marine iguanas, while the others may feed on their young or eggs. This inhibits reproduction and the long-term survival of the species. Introduced predators represent a major problem on the islands of Santa Cruz, Santiago, Isabela, Floreana and San Cristóbal where very few marine iguana hatchlings survive. Marine iguanas are ecologically naïve and have not developed efficient anti-predator strategies against the introduced species. For example, the first dogs were introduced to the Galápagos Islands more than 100 years ago, but marine iguanas have not developed an anti-predator strategy against them. In general, native predators represent a less serious threat to the marine iguana. Natural land predators include the Galápagos hawk, short-eared owl, lava gull, herons and Galápagos racer snakes that may take small marine iguanas. When swimming, marine iguanas are occasionally attacked and eaten by sharks, although the two often behave indifferently to each other, even when close together. Of the native predators, the Galápagos hawk is likely the most important, and it may also take weakened adults (not just young), but this hawk is quite rare with a total population numbering only a few hundred individuals. Marine iguanas have anti-predator strategies that reduce the impact of the Galápagos hawk, including an increased vigilance when hearing the alarm call of the Galápagos mockingbird, another species that is sometimes preyed upon by the hawk.
Marine iguanas can easily be approached by humans as they are very tame and generally make little or no attempt to escape. Individuals that have been caught before are only slightly more wary when again encountering humans. Even when repeatedly caught and deliberately mishandled each time, they do not attempt to bite or lash with their tail in self-defense (although the sharp claws can cause painful scratches when the iguana attempts to gain a grip) and only move a few feet once released, allowing themselves to be caught again with ease. Pathogens introduced to the archipelago by humans pose a serious threat to this species. The marine iguana has evolved over time in an isolated environment and lacks immunity to many pathogens. As a result, the iguanas are at higher risk of contracting infections, contributing to their threatened status.
Occasional oil spills in the region also present a threat. For example, the Santa Fé population was reduced by almost 2⁄3 as a result of the MV Jessica oil spill in 2001, and even low-level oiling may kill marine iguanas. It is suspected that the primary cause of death during these events is starvation due to the loss of their sensitive gut bacteria, which they rely on to digest algae.


Ambrosia artemisiifolia, with the common names common ragweed, annual ragweed, and low ragweed, is a species of the genus Ambrosia native to regions of the Americas.


Ambrosia artemisiifolia is an annual plant that emerges in late spring. It propagates mainly by rhizomes, but also by seed.
It is much-branched, and grows up to 70 centimetres (2.3 ft) in height. The pinnately divided soft and hairy leaves are 3–12 centimetres (1.2–4.7 in) long.
Its bloom period is July to October in North America. Its pollen is wind-dispersed, and can be a strong allergen to people with hay fever.
It produces 2–4 mm obconic green to brown fruit. It sets seed in later summer or autumn. Since the seeds persist into winter and are numerous and rich in oil, they are relished by songbirds and upland game birds.


Common ragweed, Ambrosia artemisiifolia, is a widespread invasive species, and can become a noxious weed, that has naturalized in: Europe; temperate Asia and the Indian subcontinent; temperate northern and southern Africa and Macaronesia; Oceania in Australia, New Zealand, and Hawaii; and Southwestern North America in California and the Southwestern United States.
Common ragweed is a very competitive weed and can produce yield losses in soybeans as high as 30 percent. Control with night tillage reduces emergence by around 45 percent. Small grains in rotation will also suppress common ragweed if they are overseeded with clover. Otherwise, the ragweed will grow and mature and produce seeds in the small grain stubble.
Its wind-blown pollen is highly allergenic.


Three sesquiterpene lactones isolated from the aerial parts of Ambrosia artemisiifolia were identified as psilostachyin A, psilostachyin B and psilostachyin C. All of them have some molluscicidal activity against the small tropical freshwater snail Oncomelania hupensis.


The northwestern salamander (Ambystoma gracile) is a species of mole salamander that inhabits the northwest Pacific coast of North America.  These fairly large salamanders grow to 8.7 in (220 mm) in length. It is found from southeastern Alaska on May Island, through Washington and Oregon south to the mouth of the Gualala River, Sonoma County, California. It occurs from sea level to the timberline, but not east of the Cascade Divide. Its range includes Vancouver Island in British Columbia and The San Juan Islands, Cypress, Whidbey, Bainbridge, and Vashon Islands in Washington.


The spotted forms occur in the northern portion of its range. A dividing line of 51°N latitude has been recognized between the two subspecies, with A. g. decorticatum occurring north of the line and A. g. gracile living to the south.
Populations with neotenic adults are widespread; the frequency of gilled adults increases with altitude such that adults at low and intermediate altitudes are almost all terrestrial, while adults at very high elevations are mostly neotenic.
An example of a paedomorphic population of the northwestern salamander occurs at Crater Lake, Oregon; the population is syntopic with Taricha granulosa.
Terrestrial adults live in mesic habitats ranging from grasslands to mesophytic forests. Terrestrial adults are mostly fossorial, and are usually active on the surface only during fall rains and spring migrations to their aquatic breeding sites. However, they can sometimes be found under logs and other surface debris outside of the breeding season.
Adult salamanders eat small terrestrial invertebrates such as insects, worms, and arachnids.  Larvae and juveniles consume aquatic invertebrates including snails, worms, and tadpoles.


The Jefferson salamander (Ambystoma jeffersonianum) is a mole salamander native to the northeastern United States, southern and central Ontario, and southwestern Quebec. It was named after Jefferson College in Pennsylvania.
It is typically dark gray, brown, or black on its dorsal surface, but a lighter shade on its anterior. Some individuals may also have silver or blue specks on their sides; the area around the vent is usually gray. These salamanders are slender, with a wide nose and distinctive long toes, and range in size from 11 to 18 cm (4.3 to 7.1 in).
Like other mole salamanders, the Jefferson salamander burrows; they have well-developed lungs suited for this purpose. Nocturnal by nature, they can be spotted by day during the mating season. Breeding occurs in early spring, after the snow in the area has melted.


The secretive adults tend to hide under stones or logs, or in leaf litter and other underbrush in deciduous forests during damp conditions. They are usually not found in conifer forests, likely due to the dryness and prickliness of some pine and spruce needles, which may injure amphibians with their thin skins. They are found burrowed underground for most of the year during dry or freezing conditions. They must get below the frost line (about 18 inches) in order to survive winter conditions in northern latitudes. They often burrow in rich sandy soils found in upland deciduous forests or sometimes in older-growth damp hemlock forests.
Because breeding sites are usually close to the over-wintering burrows, migration to their breeding area is quick, and usually occurs during or immediately after a heavy rainfall. The breeding sites they choose are fishless ponds and vernal pools, filled with spring snow meltwater in northern latitudes. Some breeding ponds may be hundreds of yards (meters) away from their forest home in fragmented landscapes.
Jefferson salamanders are one of the first amphibians to emerge in springtime at the northern edge of their range in southern Ontario where they are seen "snowshoeing" across the still frozen understory of the forest to reach partially melted breeding ponds. Males migrate first with females following shortly thereafter. These salamanders have small pores on their heads which exude a whitish liquid when they are handled, suggesting that they may leave a scent trail during migration, Ambystoma jeffersonianum is often found in the same habitat as the spotted salamander.


Blue-spotted salamanders are primarily found in moist, deciduous hardwood forests and swampy woodlands, though they can be found in coniferous forests and fields too. They prefer vernal pools that retain water into mid-summer, to ensure access to a suitable breeding habitat. Underbrush, leaf litter, rocks and logs are commonly used for shelter. Studies are beginning to show that habitat selection may also be affected by factors such as light pollution and chemical hues.


The spotted salamander or yellow-spotted salamander (Ambystoma maculatum) is a mole salamander common in eastern United States and Canada. The spotted salamander is the state amphibian of Ohio and South Carolina. This salamander ranges from Nova Scotia, to Lake Superior, to southern Georgia and Texas. Its embryos have been found to have symbiotic algae living in and around them, the only known example of vertebrate cells hosting an endosymbiont microbe (unless mitochondria are considered).


The spotted salamander is about 15–25 cm (5.9–9.8 in) long. They are stout, like most mole salamanders, and have wide snouts. The spotted salamander's main color is black, but can sometimes be a blueish-black, dark gray, dark green, or even dark brown. Two uneven rows of yellowish-orange spots run from the top of the head (near the eyes) to the tip of the tail. The spotted salamander's spots near the top of its head are more orange, while the spots on the rest of its body are more yellow. The underside of the spotted salamander is slate gray and pink. Sexual dimorphism, physical differences between males and females, is displayed in the form of larger-bodied females having brighter-coloured spots.
The scientific name Ambystoma maculatum comes from Ambystoma– amblys (Greek) for blunt; -stoma (Greek) meaning mouth; or anabystoma (New Latin) meaning ‘to cram into the mouth’ maculatum – macula (Latin) for spot; maculosus (Latin) for spotted.


Spotted salamanders feed on earthworms, slugs, snails, spiders, millipedes, centipedes, insects, and other invertebrates. They sometimes also feed on smaller salamanders, such as the red-backed salamander. The adult spotted salamander uses its sticky tongue to catch food.


During the majority of the year, spotted salamanders live in the shelter of leaves or burrows in deciduous forests. However, when the temperature rises and the moisture level is high, the salamanders make their abrupt migration towards their annual breeding ponds. In just one night, hundreds to thousands of salamanders may make the trip to their ponds for mating. Males migrate at higher rates than females early in the migration season. This could be due to different responses to temperature between males and females. Mates usually breed in ponds when it is raining in the spring. Females usually lay about 100 eggs in one clutch that cling to the underwater plants and form egg masses.
The egg masses are round, jelly-like clumps that are usually 6.4–10.2 cm (2.5–4 in) long. The spotted salamander produces a unique polymorphism in the outer jelly layers of its egg masses: one morph has a clear appearance and contains a water-soluble protein, whereas the other morph is white and contains a crystalline hydrophobic protein. This polymorphism is thought to confer advantages in vernal pools with varying dissolved nutrient levels, while also reducing mortality from feeding by wood frog larvae.

Adults only stay in the water for a few days, then the eggs hatch in one to two months.When the eggs hatch depends on the water temperatures. Eggs of A. maculatum can have a symbiotic relationship with the green alga Oophila amblystomatis. A dense gelatinous matrix surrounds the eggs and prevents the eggs from drying out, but it inhibits oxygen diffusion (required for embryo development). The Oophila alga provides increased oxygen and supplemental nutrition from fixed carbon products via photosynthesis and removes the embryo’s nitrogenous waste (ammonia) in the egg capsule, aiding in the salamander's embryonic development and growth. The developing salamander thus metabolizes the oxygen, producing carbon dioxide (which then the alga consumes). Photosynthetic algae are present within the egg capsule of the developing salamander embryo, enhancing growth. However, the widely used herbicide, atrazine, has been found to significantly lower hatching success rate by eliminating the symbiotic algae associated with the egg masses.
 As larvae, they are usually light brown or greenish-yellow. They have small dark spots and are born with external gills. In two to four months, the larvae lose their gills, and become juvenile salamanders that leave the water. Spotted salamanders have been known to live up to 32 years, and normally return to the same vernal pool every year. These pools are seasonal and will usually dry up during the late spring and stay dry until winter.
Spotted salamanders are often preyed on by raccoons, skunks, turtles, and snakes. However, one of their top predators is humans since they are popularly sought out through the pet trade.


Marbled salamanders are found in the eastern United States, from southern New England to northern Florida, and west to Illinois and Texas. They have been found as far north as New Hampshire, though only two sightings have been reported there. Their habitats are damp woodlands, forests, and places with soft and wet soil. Seasonally flooded areas are essential for breeding, but the salamanders do not normally enter the water. Like many salamanders, marbled salamanders have poison glands to deter predators.
The marbled salamander is the state salamander of North Carolina.


The first months that Marbled Salamanders spend living out of the water are the most important in determining how many will survive until the next breeding season. Marbled Salamanders are not strong burrowers, therefore they rely on existing holes in the ground for shelter. Desiccation, heat stress, soil moisture, temperature, and pH are all important factors in determining if a Marbled Salamander will survive. Chances of survival are low for Marbled Salamanders who travel through fields, however, they have been observed to traverse fields in order to find other pond areas. Marbled Salamanders survive best in a forest habitat, compared to an open field. Protecting wetlands is key to the survival of this species. Conservationists recommend leaving a buffer zone of forest around wetlands to increase survivorship of Marbled Salamanders. Marbled Salamanders in the northern portions of their range can also go into a state of torpor to survive the cold months.
Adults spend most of their time in their burrows or under logs, as is the case with most mole salamanders. Juvenile marbled salamanders hatch early compared to most salamanders and gain a size advantage by feeding and growing for several months before the Jefferson salamanders and spotted salamanders hatch later in the spring. Larvae typically mature as quickly as two months in the southern part of their range, but take up to six months to mature in the northern part.
Marbled salamanders, like other members of this genus, are reported to have relatively long life spans, 8–10 years or more.


Adults take terrestrial invertebrates, such as worms, insects, centipedes, and mollusks (snails, slugs). Larvae take small aquatic animals (zooplankton), but larger individuals will take eggs and larvae of other amphibians, as well.
Marbled Salamanders are considered a keystone predator because they alter the competitive ability of their prey, allowing other species of prey to thrive.


When A. opacum is under attack by a predator, they often exhibit tail lashing, head-butting, body coiling, or potentially becoming immobile. These defensive moves are thought to draw attention to the tail, which has granular glands that produce noxious secretions to protect themselves. While some predators have learned to eat the body of Marbled Salamanders and leave the tail, this is still a deterrent for many predators. A problem with the granular glands Marbled Salamanders possess is that secretions are reduced after multiple attacks, making them more vulnerable


These salamanders usually grow to a length of 6–8 in (15–20 cm) with a lifespan of around 12–15 years. They are characterized by having markings varying in color on the back of their head, body, and tail. The coloring of these spots range from brownish yellow to greenish yellow, while the rest of their back is black or dark brown. They have short snouts, thick necks, strong legs, and lengthy tails. Their diet consists largely of small insects, snails, slugs, frogs, and worms, although it is not rare for an adult to turn cannibalistic and consume its own kind. Cannibalism in these salamanders can almost always be traced back to a large volume of competing predators and lack of prey in the area. If the opportunity presents itself, tiger salamanders will even feed on other smaller salamander species, snakelets (baby snakes), and newborn mice.
Illinois citizens voted for the eastern tiger salamander as state amphibian in 2004, and the legislature enacted it in 2005.


Tiger salamanders habitats range from woodlands crowded with conifer and deciduous trees to grassy open fields. These amphibians are secretive creatures who spend most of their lives underground in burrows, making them difficult to spot. One significant requirement these salamanders need to thrive is loose soil for burrowing. Tiger salamanders are almost entirely terrestrial as adults, and usually only return to the water to breed. The ideal breeding condition for tiger salamanders ranges from wetlands, such as cattle ponds and vernal pools, to flooded swamps. This species is most commonly found on the Atlantic coast from New York down to Florida. They are known, however, to be the widest ranging species of salamander in North America and have been found in smaller populations from coast to coast. Ambystoma tigrinum populations  occurring in northern and eastern regions of the United States are thought to be native populations as evidence from a study uncovered the species in these regions seem to be from relict populations. The species which occur on the west coast of the United States are not necessarily native occurring to the region and occur as a result of introduction for sport fishing bait, which has resulted in hybridization.
Though tiger salamanders aren't indicators of an ecosystem, they are good indicators of a healthy environment because they need good moist soil to burrow in. But pond disturbance, invasive fish, and road construction threaten the annual population.


Like all ambystomatids, they are extremely loyal to their birthplaces, and will travel long distances to reach them. However, a single tiger salamander has only a 50% chance of breeding more than once in its lifetime. In a study conducted in South Carolina, breeding migrations of adult tiger salamanders began in late October or November for males and November through February for females.The tiger salamander's ideal breeding period is somewhere between the late winter and early spring, once the ground is warm enough and the water is thawed. Males nudge a willing female to initiate mating, and then deposit a spermatophore on the lake bottom. About 48 hours after insemination, the female is ready to deposit her eggs in the breeding pool. One female can lay up to 25-30 eggs per egg mass. She carefully attaches the eggs to secure twigs, grass, and leaves at the bottom of the pool to ensure her eggs safety. In about 12–15 days time, the eggs will be fully hatched and ready to mature in the pool. It takes a tiger salamander approximately 3 months to reach full maturity and leave the breeding pool. Large-scale captive breeding of tiger salamanders has not been accomplished, for unknown reasons.
The larva is entirely aquatic, and is characterized by large external gills and a prominent caudal fin that originates just behind the head, similar to the Mexican axolotl. Limbs are fully developed within a short time of hatching. Some larvae, especially in seasonal pools and in the north, may metamorphose as soon as feasible. These are known as small morph adults. Other larvae, especially in ancestral pools and warmer climates, may not metamorphose until fully adult size. These large larvae are usually known as 'waterdogs', and are used extensively in the fishing bait and pet trades. Some populations may not metamorphose at all, and become sexually mature while in their larval form. These are the neotenes, and are particularly common where terrestrial conditions are poor.


The black bullhead or black bullhead catfish (Ameiurus melas) is a species of bullhead catfish. Like other bullhead catfish, it has the ability to thrive in waters that are low in oxygen, brackish, turbid and/or very warm. It also has barbels located near its mouth, a broad head, spiny fins, and no scales. It can be identified from other bullheads as the barbels are black, and it has a tan crescent around the tail. Its caudal fin is truncated (squared off at the corners). Like virtually all catfish, it is nocturnal, preferring to feed at night, although young feed during the day.  It generally does not get as large as the channel or blue catfish, with average adult weights are in the 1- to 2-lb range, and almost never as large as 4 lb. It has a typical length of 8-14 in, with the largest specimen being 24 in, making it the largest of the bullheads. It is typically black or dark brown on the dorsal side of its body and yellow or white on the ventral side.
Like most of the bullheads (and even flathead catfish), it has a squared tail fin, which is strikingly different from the forked tail of channel and blue catfish. It is a bottom-rover fish, meaning it is well-adapted for bottom living. It is typically dorsoventrally flattened, and has a slightly humped back.  Its color depends on the area where it is taken, but it generally is darker than brown or yellow bullheads. It can be distinguished from a flathead in that the black bullhead's lower lip does not protrude past the upper lip.  Distinguishing it from the brown bullhead is a bit more difficult, depending on the area where it is caught, but a distinguishing detail between the two includes a nearly smooth pectoral spine on the black bullhead with the brown being strongly barbed. The anal fin also has a gray base, and the tail also has a pale bar. Also, the brown bullhead generally has 21 to 24 soft rays through its anal fin as opposed to the black bullhead's 17 to 21. The brown bullhead is also typically mottled brown and green on top instead of the darker black. Both the black and brown bullheads can easily be distinguished from the yellow bullhead as the yellow bullhead has white barbels under its mouth.


Considered rough fish, black bullheads are not as popular for sport fishing as their larger relatives, channel catfish, blue catfish, and flat head catfish. However, they have pale flesh and make excellent table fare when water quality is good despite their small size. As with channel catfish, the flesh around the bellies and gills of larger individuals can be strong tasting due to yellow fat, but these flavors can be avoided by removing the fatty portions of a large specimen when cleaning.  They are the largest of the bullheads and are one of several catfish informally referred to as mud catfish.
They have been introduced in many areas of the US because of their ability to survive (and even thrive) in less than ideal conditions, but they are seldom used in active stocking programs due to their relatively low desirability. Fisheries experts tend to not recommend them because they compete with bluegill and channel catfish for food and do not grow as fast or get as big as channel catfish.  For that reason, finding them commercially for pond stocking is difficult.  That said, in clean water, meat quality is very good, and unlike channel catfish, black bullheads reproduce and indefinitely maintain healthy populations without restocking in ponds populated with bass and crappie.  In fact, as with bluegill, a pond with black bullhead in it needs a predator species such as bass to keep the bullhead population under control.  Due to their ability to reproduce in a pond with bass, bullheads are the best catfish for mixed-species ponds that are not fished out and restocked regularly.
Black bullheads can be caught using similar techniques as for channel or blue catfish, although their small size may require smaller bait and hooks. They respond well to earthworms and tend to feed higher up in the water column than channel catfish.  Like most catfish, they are most active at night, and tend to be less active during the day, bedding under piers or in shady shore areas.
In some areas of little to no fishing pressure, black bullheads have been found to be more aggressive and have been caught while casting and retrieving metal spoon lures.


The yellow bullhead is a medium-sized member of the catfish family. It is typically yellow-olive to slate black on the back and may appear mottled depending on its habitat. The sides are lighter and more yellowish, while the underside of the head and body are bright yellow, yellow white, or bright white. The rear edge of its caudal fin is rounded. The anal fin is much longer than those of other bullheads, having anywhere between 24 and 27 rays. The yellow bullhead, though less common, can be easily distinguished from the brown bullhead and black bullhead by the group of white barbels or "whiskers" under its chin. Yellow bullheads are medium-sized bullheads that rarely grow larger than 2 lb (0.91 kg), but can reach up to 6.375 lb (2.892 kg). Yellow bullheads range in size from 6 to 14 inches, and can live up to 12 years.


The yellow bullhead is a voracious scavenger that will almost eat anything. It locates prey by brushing the stream bottom with its barbels. Taste buds on the barbels tell the yellow bullhead whether or not contact is made with edible prey. They typically feed at night on a variety of plant and animal material, both live and dead, most commonly consisting of worms, insects, snails, minnows, clams, crayfish, other small aquatic organisms, plant matter, and decaying animal matter. Compared to black and brown bullheads, yellow bullheads consume more aquatic vegetation.


Yellow bullheads are considered a minor game fish, and their meat is considered sweet and has a good flavor, but the meat can become soft in summer. They are not as sought after as other catfish. They can be caught on natural baits such as worms, crickets or chicken liver fished on the bottom at night.