The brown bullhead (Ameiurus nebulosus) is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (Ameiurus melas) and yellow bullhead (Ameiurus natalis). It was originally described as Pimelodus nebulosus by Charles Alexandre Lesueur in 1819, and is also referred to as Ictalurus nebulosus.
The brown bullhead is also widely known as the "mud pout", "horned pout", "hornpout", or simply "mud cat", a name also used with the other bullhead species.
The brown bullhead is important as a clan symbol of the Ojibwe people. In their tradition, the bullhead or wawaazisii is one of six beings that came out of the sea to form the original clans.


The brown bullhead grows to be approximately 21 inches (53 cm) in length and is a darker brown-green dorsally, growing lighter green and yellow towards the ventral surface. The belly is off-white or cream, and the fish has no scales. Additionally, there are darker, brown-black speckles along the entire surface of the fish. The brown bullhead has two dorsal fins, a single adipose fin, abdominal pelvic fins, and an anal fin with 21 to 24 rays. The tail is only slightly notched, with the dorsal and ventral lobes angling inward. The fish has barbels around the mouth and on the pelvic spine. The barbels around the mouth are black to yellowish brown on the chin and saw-like on the pelvic spines. Juvenile brown bullheads are similar in appearance, but are more likely to be of a single solid color.
The brown bullhead's mouth is slightly subterminal, with the upper jaw extending slightly past the lower jaw. This position enables bottom feeding. The brown bullhead may be distinguished from similar species by the absence of a tooth patch on its upper jaw with the lateral backwards extensions. Adult brown bullheads range in size from 200 to 500 mm (7.9 to 19.7 in) and weigh between 0.5 kg (1.1 lb) and 3.6 kg (7.9 lb) (in extreme cases). Brown bullheads are ectothermic, heterothermic, and bilaterally symmetrical. Brown bullheads can be distinguished from black and yellow bullheads by their yellow-black chin barbels, the missing bar at the base of the tail (which is present in black bullheads), and their 21–24 anal fin rays.


The native range of the brown bullhead is in the Atlantic and Gulf Slope drainages. More specifically, it is found from Nova Scotia and New Brunswick to Mobile Bay, Alabama, and in the Great Lakes, Hudson Bay, and Mississippi River basins (from Quebec to Saskatchewan, south to Louisiana, and west to Texas). However, there is evidence that the brown bullhead was historically absent from the Gulf Coast west of the Apalachicola River and east of the Mississippi River. The species is also abundant in many regions as a result of stocking for food or sport. These locations include Georgia,Alabama, Arizona, Arkansas, California, Colorado, Hawaii, Idaho, Kansas, Kentucky, Louisiana, Maine, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, Ohio, Oklahoma, Oregon, Virginia, and Washington. Brown bullheads are a social non-migratory species that lives the majority of their lives in schools.


The brown bullhead thrives in a variety of habitats, including lakes, ponds, and slow-moving streams with low oxygen or muddy conditions. In many areas of the United States, brown bullheads are opportunistic bottom feeders. The species has few natural predators and is not popular with fishermen, so it has thrived. Catfish are found in a variety of habitats, from lakes or murky ponds to drainage ditches. They are scarce during the day, but come out at night to feed, searching the bottom of a lake or river for food. They eat insects, leeches, snails, fish, clams, and many plants. They are also known to eat corn, which can be used as bait. Similarly to other catfish, they spawn only after the temperature of the water has reached 80 °F (27 °C) in June and July. However, cooler temperatures are required before brown bullheads will spawn in the northern US.
 Brown bullheads can withstand a wide range of water temperatures and low oxygen levels. Brown bullheads can survive waters with heavy pollution and dissolved oxygen values as low as 0.2 ppm. Because of bullheads' tolerance of low oxygen levels, they are less threatened by winterkill and are capable of surviving in relatively extreme environments.


The fish has been introduced into many European countries, such as Poland, Germany, Sweden, Norway, Finland, Romania, Estonia, Hungary, Serbia, and Croatia. Brown bullheads have also been introduced to western North America, Chile, Puerto Rico and New Zealand.
 Countries who have reported adverse effects from the introduction of the brown bullhead species include Iran and Turkey.


Brown bullheads are the most susceptible to predators in their developmental stages, primarily as eggs. They are prey to the following species: northern pike, muskellunge, walleye, snapping turtles, water snakes, green herons, yellow perch, and sunfish. Additionally, brown bullheads are used for small-scale commercial fishing, recreational fishing, and more specifically for consumption and research. Predation by other fish and coexisting species is only a realistic threat to bullheads under four inches, while the biggest threat to adult bullheads is humans. Brown bullheads have protective coloration to avoid predation. As a mode of physical defense against predators, bullhead species have a sharp spine on the leading edge of their dorsal and pectoral fins. To use this adaptation as a defense mechanism, bullheads will stiffen the spine while being attacked, impeding the predator's ability to swallow while simultaneously releasing a venom to sting and burn the predator.


It is widespread in Central America and South America, including: Panama, Brazil, Colombia, Surinam, French Guiana, Guyana, Venezuela, Bolivia, Ecuador, Peru, Argentina, and Paraguay. It is also found on the Caribbean islands of Trinidad and Tobago, Grenada, the Grenadines, Barbados, Margarita, Swan Island, and Isla de la Providencia.  It was also once present on Saint Vincent but has since been extirpated.


Amelanchier spicata, also referred to as the low juneberry, thicket shadbush, dwarf serviceberry, or low serviceberry (historically also called "pigeon berry"), is a species of serviceberry that has edible fruit, which are really pomes. They can be eaten raw or cooked. Amelanchier spicata has clusters of small white flowers that bloom in spring.
Amelanchier spicata is native to North America. It is a very hardy species, and is considered invasive in Scandinavia.


Ameles spallanzania can reach a length of 18–40 millimetres (0.71–1.57 in). Their colour may be brown, green, ocher or grey. The eyes are slightly pointed, antennae are threadlike, the pronotum is short and squared and the broad abdomen of the females is commonly curled upwards. This very small mantid (hence the common name) is characterized by an evident sexual dimorphism. The males are winged and have a quite slender body, while females show stubby bodies and are unable to fly, as they possess only small wing vestiges (brachypterous).


This species can be found in the Mediterranean area, from Morocco to Greece and from southern Europe to northern Africa (Albania, Algeria, Dalmatia, France, Greece, Italy, Malta, Libya, Morocco, Portugal, Spain, Tunisia).


Colonists and early Native Americans made jewelry from these shells.
The lettered olive is the state shell of South Carolina.


The bowfin (Amia calva) is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being the sole surviving species of the Halecomorphi, a group of fish that first appeared during the Early Triassic, around 250 million years ago. The bowfin is often considered a "primitive fish" because they have retained some morphological characteristics of their early ancestors. The closest living relatives of bowfins are gars, with the two groups being united in the clade Holostei.
Bowfins are demersal freshwater piscivores, commonly found throughout much of the eastern United States, and in southern Ontario and Quebec. Fossil deposits indicate Amiiformes were once widespread in both freshwater and marine environments  across North and South America, Europe, Asia, and Africa. Now, their range is limited to much of the eastern United States and adjacent southern Canada, including the drainage basins of the Mississippi River, Great Lakes, and various rivers exiting in the Eastern Seaboard or Gulf of Mexico. Their preferred habitat includes vegetated sloughs, lowland rivers and lakes, swamps, and backwater areas; they are also occasionally found in brackish water. They are stalking, ambush predators known to move into the shallows at night to prey on fish and aquatic invertebrates such as crawfish, mollusks, and aquatic insects.
Like gars, bowfin are bimodal breathers – they have the capacity to breathe both water and air. Their gills exchange gases in the water allowing them to breathe, but they also have a gas bladder that serves to maintain buoyancy, and also allows them to breathe air by means of a small pneumatic duct connected from the foregut to the gas bladder. They can break the surface to gulp air, which allows them to survive conditions of aquatic hypoxia that would be lethal to most other species.


The typical length of a bowfin is 50 cm (20 in); females typically grow to 65–70 cm (26–28 in), males to 50–65 cm (20–26 in). They can reach 109 cm (43 in) in length, and weigh 9.75 kg (21.5 lb). Young of the year typically grow to 13–23 cm (5.1–9.1 in) by October. Females tend to grow larger than males.
The body of the bowfin is elongated and cylindrical, with the sides and back olive to brown in color, often with vertical bars and dark reticulations or another camouflaged pattern. The dorsal fin has horizontal bars, and the caudal fin has irregular vertical bars. The underside is white or cream, and the paired fins and anal fin are bright green. During larval stage, hatchlings from about 7–10 mm (0.28–0.39 in) total length are black and tadpole-like in appearance. At approximately 25 mm (0.98 in) total length they have been described as looking like miniature placoderms. They grow quickly, and typically leave the nest within 4 to 6 weeks after hatching. Young males have a black eyespot on the base of the tail (caudal peduncle) that is commonly encircled by an orange-yellowish border, while the female's is black, if present at all. It is thought the purpose of the eyespot is to confuse predators, deflecting attacks away from the head of the fish to its tail, which affords the bowfin an opportunity to escape predation. The bowfin is so named for its long, undulating dorsal fin consisting of 145 to 250 rays that runs from the middle of the back to the base of the tail.
The skull of the bowfin is made of two layers of skull, the dermatocranium and the chondrocranium. The chondrocranium layer cannot be seen because it is located below the dermal bones. The bowfin skull is made up of 28 fused bones, which compose the dermatocranium. The roof of the mouth is made up of three bones, the ectopterygoid, the palantine, and the vomer. They have two sets of teeth, including one set of larger sharp teeth coming out of the mandibular and premaxillary bones to grasp and control the prey. The other set of teeth, located posteriorly and connected to the hyomandibular bone, is made up of pharyngeal tooth patches, which are used for sorting out nutrients and grinding down larger pieces of food.   Another three bones make up the lower jaw: the dentary, the angular, and the surangular. The cranial surface of the skull is made up of the nasals, the antorbital, the lacrimal, the parietal, the intertemporal, the post parietal, the supratemporal, the extra scapular, the post temporal, and the opercular. The entirety of the skull is attached to the girdle through another set of bones.
Bowfin are often referred to as "living fossils", or "primitive fish" because they retained some of the primitive characters common to their ancestors, including a modified (rounded externally) heterocercal caudal fin, a highly vascularized gas bladder lung, vestiges of a spiral valve, and a bony gular plate. The bony gular plate is located underneath the head on the exterior of the lower jaw between the two sides of the lower jaw bone. Other distinguishing characteristics include long, sharp teeth, and two protruding tube-like nostrils. Unlike all of the most primitive actinopterygians, the scales of bowfin differ in that they are not ganoid scales, rather they are large, single-layered cycloid scales closer in similarity to more derived teleosts.


Bowfin, like other physostomes such as bichirs (Polypteridae), gars (Lepisosteidae), and the lungfish (Dipnoi), are capable of bimodal respiration. They can extract oxygen from the water when breathing through their gills, and can also break the water's surface to breathe or gulp air through a small pneumatic duct connected from their foregut to the gas bladder. When performing low-level physical activity, bowfin obtain more than half of their oxygen from breathing air. Bowfin have two distinct air-breathing mechanisms used to ventilate the gas bladder. Air breathing type I is consistent with the action of exhale / inhale exchange, stimulated by either air or water hypoxia, to regulate O₂ gas exchange; type II air breaths are inhalation alone, which is believed to regulate gas bladder volume, to control buoyancy. Bimodal respiration helps bowfin survive and maintain their metabolic rate in hypoxic conditions. The rate of air breathing is higher in darkness, when the fish is more active.
Bowfin blood can adapt to warm, acidic waters. The fish becomes inactive in waters below 10 °C (50 °F); at this temperature they breathe almost no air; however, with increasing temperature their air breathing increases. Their preferred temperature range is between 12–26 °C (54–79 °F), with 18 °C (64 °F) the temperature of maximum activity. Air breathing is at a maximum in the range 18.4–29.6 °C (65.1–85.3 °F). Bowfin do not use central chemoreceptor regulation for respiration control. Experiments manipulating the oxygen content, carbon dioxide content, and pH of bowfin extradural fluid did not affect breathing rate, heart rate, or blood pressure pointing to a lack of central chemoreceptor regulation. Instead, bowfin respiratory patterns respond to water oxygen content and water temperature, as water temperatures play a role in oxygen content. In the lab, bowfin showed an increase in the breathing rate when the temperatures were raised above 10°C. Bowfin also showed an increase in breathing rate when exposed to lower oxygen levels in the water.
Herpetologist W.T. Neill reported in 1950 that he unearthed a bowfin aestivating in a chamber 4 inches (10 cm) below the ground surface, 8 inches (20 cm) in diameter, .25 miles (0.4 km) from a river. It was further noted that flood levels had previously reached the area, and receded. It is not unusual for riverine species like bowfin to move into backwaters with flood currents, and become trapped when water levels recede. While aestivation is anecdotally documented by multiple researchers, laboratory experiments have suggested instead that bowfin are physiologically incapable of surviving more than three to five days of air exposure. However, no field manipulation has been performed. Regardless of the lack of evidence confirming the bowfin's ability to aestivate, it has been noted that bowfin can survive prolonged conditions of exposure to air because they have the ability to breathe air. Their gill filaments and lamellae are rigid in structure which helps prevent the lamellae from collapsing and aids gas exchange even during air exposure.


Competing hypotheses and debates continue over the evolution of Amia and relatives, including their relationship among basal extant teleosts, and organization of clades. Bowfin are the last remaining member of Halecomorphi, a group that includes many extinct species in several families. Halecomorphs were generally accepted as the sister group to Teleostei but not without question. While a halecostome pattern of neopterygian clades was produced in morphology-based analyses of extant actinopterygians, a different result was produced with fossil taxa which showed a monophyletic Holostei. Monophyletic Holostei were also recovered by at least two nuclear gene analyses, in an independent study of fossil and extant fish, and in an analysis of ultraconserved genomic elements.
The extant ray-finned fish of the subclass Actinopterygii include 42 orders, 431 families and over 23,000 species. They are currently classified into two infraclasses, Chondrostei (holosteans) and Neopterygii (teleost fishes). Sturgeons, paddlefish, bichirs and reed fish compose the thirty-eight species of chondrosteans, and are considered relict species. Included in the over 23,000 species of neopterygians are eight relict species comprising gars and the bowfin.


Fossil deposits indicate amiiforms included freshwater and marine species that were once widely distributed in North America, South America, Eurasia and Africa. Today, bowfin (Amia calva) are the only remaining species in the order Amiiformes; they are demersal freshwater piscivores, and their range is restricted to freshwater environments in North America, including much of the eastern United States and adjacent southern Canada from the St. Lawrence River and Lake Champlain drainage of southern Ontario and Quebec westward around the Great Lakes in southern Ontario into Minnesota. Historically, their distribution in North America included the drainage basins of the Mississippi River from Quebec to northern Minnesota, the St. Lawrence-Great Lakes, including Georgian Bay, Lake Nipissing and Simcoe, Ontario, south to the Gulf of Mexico; Atlantic and Gulf Coastal Plain from the Susquehanna River drainage in southeastern Pennsylvania to the Colorado River in Texas.


Bowfin prefer vegetated sloughs, lowland rivers and lakes, swamps, backwater areas, and are occasionally found in brackish water. They are well camouflaged, and not easy to spot in slow water with abundant vegetation. They often seek shelter under roots, and submerged logs. Oxygen-poor environments can be tolerated because of their ability to breathe air.


Bowfin spawn in the spring or early summer, typically between April and June, more commonly at night in abundantly vegetated, clear shallow water in weed beds over sand bars, and also under stumps, logs, and bushes.
Optimum temperatures for nesting and spawning range between 16–19 °C (61–66 °F). The males construct circular nests in fibrous root mats, clearing away leaves and stems. Depending on the density of surrounding vegetation there may be a tunnel-like entrance at one side. The diameter of the nests commonly range between 39–91 cm (15–36 in), at a water depth of 61–92 cm (24–36 in).
During spawning season, the fins and underside of male bowfin often change in color to a bright lime green. The courtship/spawning sequence lasts one to three hours, and can repeat up to five times. Courtship begins when a female approaches the nest. The ritual consists of intermittent nose bites, nudges, and chasing behavior by the male until the female becomes receptive, at which time the pair lie side by side in the nest. She deposits her eggs while he shakes his fins in a vibratory movement, and releases his milt for fertilization to occur. A male often has eggs from more than one female in his nest, and a single female often spawns in several nests.
Females vacate the nest after spawning, leaving the male behind to protect the eggs during the eight to ten days of incubation. A nest may contain 2,000 to 5,000 eggs, possibly more. Fecundity is usually related to size of the fish, so it isn't unusual for the roe of a large gravid female to contain over 55,000 eggs. Bowfin eggs are adhesive, and will attach to aquatic vegetation, roots, gravel, and sand. After hatching, larval bowfin do not swim actively in search of food. During the seven to nine days required for yolk-sac absorption, they attach to vegetation by means of an adhesive organ on their snout, and remain protected by the parent male bowfin. Bowfin aggressively protect their spawn from the first day of incubation to a month or so after the eggs have hatched. When the fry are able to swim and forage on their own, they will form a school and leave the nest accompanied by the parent male bowfin who slowly circles them to prevent separation.
Bowfin reach sexually maturity at two to three years of age. They can live ten to twelve years in the wild, and 30 years in captivity. Females are longer-lived than males.


A common parasite of bowfin is the anchor worm (Lernaea). These small crustaceans infest the skin and bases of fins, with consequences ranging from slowed growth to death. The mollusk Megalonaias gigantea lays eggs in the bowfin gills, that are then externally fertilized by sperm passing in the water flow. The small glochidia larvae then hatch and develop in the gill tubes.
Bowfin with liver cancer and with fatal leukemia have been reported.


As a sport fish, bowfin are not considered desirable to many anglers. They were once considered a nuisance fish by anglers and early biologists who believed the bowfin's predatory nature was harmful to sport fish populations. As a result, efforts were taken to reduce their numbers. Research has since proven otherwise, and that knowledge together with a better understanding of maintaining overall balance of ecosystems, regulations were introduced to help protect and maintain viable populations of bowfin. Bowfin are strong fighters, a prized trait in game fish. However, they do have a jaw full of sharp teeth which requires careful handling. The current tackle record is 21.5 lb (9.8 kg)
Bowfin were once considered to have little commercial value because of its poor-tasting meat which has been referred to as "soft, bland-tasting and of poor texture". However, it is considered quite palatable if cleaned properly and smoked, or prepared fried, blackened, used in courtbouillion, or in fishballs or fishcakes. Over the years, global efforts have imposed strict regulations on the international trade of caviar, particularly on the harvest of sturgeons from the Caspian Sea where the highly prized caviar from the beluga sturgeon originates. The bans imposed on Caspian sturgeons have created lucrative markets for affordable substitutes in the United States including paddlefish, bowfin, and various species of sturgeon. In Louisiana, bowfin are harvested in the wild, and cultured commercially in hatcheries for their meat and roe. The roe is processed into caviar, and sold as "Cajun caviar", or marketed under the trade name "Choupiquet Royale".


The Cape river frog (Amietia fuscigula) is a species of frog in the family Pyxicephalidae named for the Cape of Good Hope.  Formerly, it was placed in the family Ranidae.  It occurs widely in the Eastern Cape and Western Cape provinces of South Africa. A newly described species, A. poyntoni, was split from this species in 2013.


The Cape river frog is a fairly large, typical frog with a snout-to-vent measurement of up to about 125 mm.  The snout is slightly rounded. It has a powerful, athletic build with long hind legs and feet, well adapted for leaping, but also well webbed; the species is a powerful swimmer. The fore feet are not webbed. When the animal sits at rest on a level surface, the tip of the longest rear toe reaches to directly below the tympanum.
The ventral skin is smooth and white, except for dark mottling on the throat. The mottling inspired the specific epithet fuscigula: Latin for "dusky throated".  In some specimens, the mottling extends to the belly. The dorsal skin bears a modest sprinkling of small, rounded protuberances and segments of longitudinal ridges. The colour scheme is variable, ranging from dark- through light-brown, also commonly green or olive, or with green streaks. The back and limbs are more or less conspicuously blotched with darker irregular spots.
Little sexual dimorphism is noted, but the male in breeding season bears a dark, swollen nuptial pad on each thumb.
The eye and tympanum are prominent; the diameter of the tympanum is barely smaller than that of the eye.


The Cape river frog occurs in a wide range of temperate to tropical habitats wherever fresh water is at least sufficient seasonally for breeding, including arable land, pastureland, savanna, shrubland, fynbos, grassland, rivers, swamps, freshwater lakes, marshes and springs, water storage areas, ponds, dams, and sewage treatment areas. Sometimes they even will occupy and breed in domestic water containers such as water butts or horse troughs.


Amietia fuscigula is largely diurnal, though its call and breeding activity are mainly nocturnal or crepuscular. It prefers permanent water and commonly colonises dams and other artificial water bodies, but in some regions it is limited to seasonal transient water bodies. Where it occupies farm dams, it commonly emerges during the morning and takes up an inconspicuous position on the bank where it basks until the sun becomes too intense near noon. While basking, it is much sought by predators such as herons and is accordingly shy; one of its most familiar manifestations is a series of plops as frogs successively leap into the water while any threat walks by. On entering the water, the alarmed frog dives strongly and either hides under the shelter of logs or stones, or scuttles briefly about the mud, obscuring itself under the opaque cloud it has made in the water. However, in situations such as garden ponds, it readily becomes habituated to inoffensive human presence.
The voice is confusingly variable, particularly where it occurs together with several other noisy species. Males may call at any time of the year in various regions, but calling peaks in the breeding season. Typically, a call begins with a rattle of clicks about 0.1 seconds apart, like a slowly played güiro or a thumbnail run over the teeth of a comb, followed by a short series of brief croaks. Where a number of calling males compete, the calls rise in pitch, volume, and speed.
It is an active opportunistic predator, readily feeding on moderately sized invertebrates such as crickets, but also attacks small reptiles, mammals, and amphibians, including smaller members of its own species.
When it occupies streams and ditches, the Cape river frog prefers deep ponds such as occur below inlets and races where the turbulent flow hollows out convenient shelters. It also prefers deep, still water for its breeding, where its tadpoles grow fairly slowly, but achieve a large size; in shallow streams, they mature more rapidly into smaller juvenile frogs. A typical size for a mature tadpole is about 80 mm, but in deep, cool, permanent water, they might grow to twice that length. In warm shallow water with plenty of food, the period of development may take about 9 months to a year, but in cold, deep water with little food, it might take two years.
In size, shape, and their brown coloration, the tadpoles are typical of large, vigorous species of frogs; they are strong swimmers with large tails about two to three times as long as the body, and with the tip tapering to a point.  The body is oval.


The Cape river frog, though locally threatened by habitat loss, for example because of dam building, is currently regarded as "least concern" because it occurs plentifully over wide areas, including in local isolated populations, and is not a specialist feeder. It also survives in altered habitats such as suitable pastureland and agricultural land


Ammophila arenaria is a European and North African native plant. It occurs in Australia, Canada, Chile, Falkland Islands (Malvinas) (sub-Antarctic), New Zealand, South Africa and United States (USA).


Usually occurs on sand dunes, sometimes in inland sites with low fertility. It occurs in the Wellington region and extends from to 55 to 32 degrees south latitude. In the Northern Hemisphere, it grows between 30 and 63 degrees north latitude. Occurs in Chatham Islands, Otago Region, Doughboy Bay and Mason Bay.


A. arenaria is one of the most problematic noxious weeds of coastal California. This sand-adapted grass was introduced to the beaches of western North America during the mid-19th century to provide stabilization to shifting sand dunes. It grew readily and it can now be found from California to British Columbia. The grass is invasive in the local ecosystems, forming dense monotypic stands that crowd out native vegetation, reduce species diversity of native arthropods, and cover vital open stretches of sand used for nesting by the threatened western snowy plover (Charadrius nivosus). The plant's spread has changed the topography of some California beach ecosystems, especially in sand dunes. The presence of this grass was a major cause of the destruction of native dune habitat in Oregon and Washington during the 20th century, where it was planted precisely for its dune-stabilizing effect.
Several methods have been employed in attempts to eradicate the grass in California, including manual pulling, burning, mechanical removal followed by salt water irrigation, and glyphosate application. Studies to find the best methods are ongoing.


Not only is it invasive in California, it is also a highly invasive weed in coastal areas of New Zealand and Western Australia, where it was introduced for the same purpose in California, to stabilise dunes; outcompeting native spinifex species. However in New Zealand the larvae of the endemic moth species Agrotis innominata has adapted to using A. arenaria as one of its main host species. It has been suggested that prior to the removal of this invasive grass from the coasts of New Zealand that surveys be undertaken to establish whether this endemic moth is present in order to assist with the conservation of that species.


The white-tailed antelope squirrel is commonly spotted in arid habitats throughout the southwestern United States. Throughout this range, Ammospermophilus leucurus is omnivorous, feeding primarily on foliage (10%-60% of its diet), seeds (20%-50%), arthropods, and to a lesser extent, vertebrates (mainly lizards and rodents; predatory behavior by ground squirrels has been noted).  In conjunction with being a predator, the white-tailed antelope squirrel is also prey to many larger animals, including raptors, various canids, and snakes. These squirrels are not only preyed upon by large predators, but they also fall victim to many diverse ectoparasites. These include various ticks, fleas, mites, lice, and a couple species of parasitic larvae.


Amorpha fruticosa is a species of flowering plant in the legume family Fabaceae, known by several common names, including desert false indigo, false indigo-bush, and bastard indigobush. It is native to North America.


Amorpha fruticosa is a perennial shrub. It grows as a glandular, thornless shrub which can reach 5 or 6 m (16 or 20 ft) in height and spread to twice that in width. It is somewhat variable in morphology. The leaves are made up of many hairy, oval-shaped, spine-tipped leaflets. The inflorescence is a spike-shaped raceme of many flowers, each with a single purple petal and ten protruding stamens with yellow anthers. The fruit is a legume pod containing one or two seeds. Its native habitats include stream and pond edges, open woods, roadsides and canyons.


It is a larval host to the clouded sulphur, gray hairstreak, hoary edge, Io moth, marine blue, silver-spotted skipper, and southern dogface.


Chorus cicada have a nymph stage before their last molt and become an adult. During this nymph stage they are a soft and creamy white, and very similar looking to the adult form (but without wings). Adults are usually larger than 2 cm in length  while the largest species are up to 4 cm; this includes the wings. Chorus cicadas’ wings only appear after molting to become adults, they are membranous with veins and they filter out ultraviolet light and the wing span is about 6 cm.
The colour of the chorus cicada can be black/green/brown and many have stripes along their body. The antenna of the chorus cicada has seven segments with the seventh being constricted medially, which means the last segment is tightened towards the middle. The adult male cicadas differ from the females by the presence of a clasper sheath, and females do not have the finger-like extensions that the males have.
The song made by cicadas is the loudest noise made by any insect. Male chorus cicadas produce a communication song that is specific to their species, and so species can be identified by their song. A pulse group of their song is made up of five clicks where the central click (third click) is stronger than the two on either side of it. The central click can become two clicks if the cicada is tired and has no energy. These clicks are made by the cicada hitting its wings against the surface it is sitting on. These pulse groups can be produced quickly and continuously in a prolonged note during chorus singing. Chorus cicadas are New Zealand's largest cicadas, with size averaging 40 mm.


Measurements:
Length: 4.7–5.5 in (12–14 cm)
Weight: 0.4–0.5 oz (11–14 g)
Wingspan: 7.7 inches (20 cm)
The black-throated sparrow is pale gray above, with a distinctive black and white head pattern. Immature birds are similar but lack a black throat. Its call is high and bell-like, and its song is a fairly simple, mechanical tinkling. It feeds primarily on insects and seeds, and travels in small groups, though larger groups may accumulate around sources of water in the desert.
It has a loose nest of grass twigs and plant fibers carefully hidden in brush 6–18 inches (15–46 cm) above the ground. Three or four white or pale blue eggs are laid.


The Mormon cricket (Anabrus simplex) is a large insect that can grow to almost 8 cm (3 inches) in length. It lives throughout western North America in rangelands dominated by sagebrush and forbs. Despite its name, the Mormon cricket is actually a shieldbacked katydid. It takes its name from Mormon settlers in Utah, who encountered them while pushing westward, and for the prominent role they play in the miracle of the gulls.
Although flightless, the Mormon cricket is capable of traveling up to two kilometers a day in its swarming phase, during which it is a serious agricultural pest and traffic hazard.


Mormon crickets have variable coloration. The overall color may be black, brown, red, purple or green. The "shield" (pronotum or modified prothorax that covers vestigial wings) behind the head may have colored markings. The abdomen may appear to be striped. Females have a long ovipositor, which should not be mistaken for a stinger. Both sexes have long antennae.
Mormon crickets may undergo morphological changes triggered by high population densities, similar to those seen in locusts. The most noticeable change is in coloration: solitary individuals typically have green or purple coloration, while swarming individuals are often black, brown or red.


The Mormon cricket exists in populations of relatively low density throughout most of its range. At certain times and places, however, population explosions or infestations occur in which large numbers of the crickets form roving bands. These bands may include millions of individuals and be found with densities of up to 100 individuals per square meter. These infestations may last years or even decades, and are characterized by a gradual increase and then decrease in population. The factors that trigger these infestations are poorly understood, but are thought to be weather-related.
Research published in 2006 shows that Mormon crickets move in these migratory bands, firstly to find new sources of the critical nutrients of protein and salt, and secondly to avoid being eaten by hungry crickets approaching from the rear. The Mormon cricket's cannibalistic behavior may lead to swarm behavior because crickets may need to move constantly forward to avoid attacks from behind.
When a large band crosses a road, it can create a safety hazard by causing distracted revulsion on the part of the driver, and by causing the road surface to become slick with crushed crickets. The crickets also can cause devastation to agriculture.


The Mormon cricket shows a marked preference for forbs, but grasses and shrubs such as sagebrush are also consumed. Mormon crickets also eat insects, including other Mormon crickets (especially individuals that have been killed or injured by automobiles or insecticides). Cannibalistic behavior may be a result of protein and salt deficiency; swarming behavior may in turn be a strategy to avoid predation by other Mormon crickets.
During an infestation Mormon crickets can cause significant damage to crops and gardens.


Mormon crickets appear in some traditional Native American diets. A journal documenting an 1846 journey along the Oregon Trail describes an encounter with the crickets and notes their cannibalistic behavior:
The ground, for a strip of about four miles, was covered with black crickets of a large size. I saw some that were about three inches in length, and measuring about three-fourths of an inch in diameter; but the common size were two inches in length and one-half or five-eighths of an inch in diameter; their legs were large in proportion to the size of their bodies. Some were singing on stalks of wild sage; others crawling in every direction. Our teams made great havoc among them; so numerous were they that we crushed them at every step. As soon as one was killed, others of them would alight upon it and devour it.
In 2003, officials in Utah, Idaho and Nevada said that year's infestation might be the worst in recent history.


This species' conservation status is vulnerable and near threatened.
It is a protected species in Northern Ireland under the Wildlife (NI) Order of 1985.
In 2001 Anacamptis morio was adopted as the logo for Priory Vale, the third and final instalment in Swindon's 'Northern Expansion' project. Due to a rapid decline in the species they are protected in certain cases, although still regarded as being quite common in the Swindon area, especially Clifford Meadow, a Site of Special Scientific Interest (SSSI) off Thamesdown Drive, Swindon.


The cashew tree (Anacardium occidentale) is a tropical evergreen tree that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as 14 metres (46 feet), but the dwarf cultivars, growing up to 6 m (20 ft), prove more profitable, with earlier maturity and greater yields. The cashew seed is commonly considered a snack nut (cashew nut) eaten on its own, used in recipes, or processed into cashew cheese or cashew butter.  Like the tree, the nut is often simply called a cashew. Cashew allergies are triggered by the proteins found in tree nuts, and cooking often does not remove or change these proteins.
In 2019, four million tonnes of cashew nuts were produced globally, with Ivory Coast and India as the leading producers. As well as the nut and fruit, the plant has several other uses. The shell of the cashew seed yields derivatives that can be used in many applications including lubricants, waterproofing, paints, and, starting in World War II, arms production. The cashew apple is a light reddish to yellow fruit, whose pulp and juice can be processed into a sweet, astringent fruit drink or fermented and distilled into liquor.


The cashew tree is large and evergreen, growing to 14 metres (46 feet) tall, with a short, often irregularly shaped trunk. The leaves are spirally arranged, leathery textured, elliptic to obovate, 4–22 centimetres (1+1⁄2–8+3⁄4 inches) long and 2–15 cm (3⁄4–6 in)  broad, with smooth margins. The flowers are produced in a panicle or corymb up to 26 cm (10 in) long; each flower is small, pale green at first, then turning reddish, with five slender, acute petals 7–15 millimetres (1⁄4–5⁄8 in) long. The largest cashew tree in the world covers an area around 7,500 square metres (81,000 square feet) and is located in Natal, Brazil.
The fruit of the cashew tree is an accessory fruit (sometimes called a pseudocarp or false fruit). What appears to be the fruit is an oval or pear-shaped structure, a hypocarpium, that develops from the pedicel and the receptacle of the cashew flower. Called the cashew apple, better known in Central America as marañón, it ripens into a yellow or red structure about 5–11 cm (2–4+1⁄4 in) long.
The true fruit of the cashew tree is a kidney– or boxing-glove–shaped drupe that grows at the end of the cashew apple. The drupe first develops on the tree and then the pedicel expands to become the cashew apple. The drupe becomes the true fruit, a single shell-encased seed, which is often considered a nut in the culinary sense. The seed is surrounded by a double shell that contains an allergenic phenolic resin, anacardic acid—which is a potent skin irritant chemically related to the better-known and also toxic allergenic oil urushiol, which is found in the related poison ivy and lacquer tree.


In 2014, rapid growth of cashew cultivation in Ivory Coast made this country the top African exporter. Fluctuations in world market prices, poor working conditions, and low pay for local harvesting have caused discontent in the cashew nut industry.
The cashew tree is cultivated in the tropics between 25°N and 25°S, and is well-adapted to hot lowland areas with a pronounced dry season, where the mango and tamarind trees also thrive. The traditional cashew tree is tall (up to 14 m) and takes three years from planting before it starts production, and eight years before economic harvests can begin. More recent breeds, such as the dwarf cashew trees, are up to 6 m tall, and start producing after the first year, with economic yields after three years. The cashew nut yields for the traditional tree are about 0.25 metric tons per hectare, in contrast to over a ton per hectare for the dwarf variety. Grafting and other modern tree management technologies are used to further improve and sustain cashew nut yields in commercial orchards.
In 2020, global production of cashew nuts (as the kernel) was 4,180,990 tonnes, led by Ivory Coast and India with a combined 39% of the world total (table). Vietnam, Burundi, and the Philippines also had significant production. Vietnam was the largest processor of cashew globally in 2020.


Raw cashews are 5% water, 30% carbohydrates, 44% fat, and 18% protein (table). In a 100 gram reference amount, raw cashews provide 553 Calories, 67% of the Daily Value (DV) in total fats, 36% DV of protein, 13% DV of dietary fiber and 11% DV of carbohydrates. Cashews are rich sources (20% or more of the DV) of dietary minerals, including particularly copper, manganese, phosphorus, and magnesium (79-110% DV), and of thiamin, vitamin B₆ and vitamin K (32-37% DV) (table). Iron, potassium, zinc, and selenium are present in significant content (14-61% DV) (table). Cashews (100 grams, raw) contain 113 milligrams (1.74 gr) of beta-sitosterol.


Some people are allergic to cashews, but they are a less frequent allergen than tree nuts or peanuts. For up to 6% of children and 3% of adults, consuming cashews may cause allergic reactions, ranging from mild discomfort to life-threatening anaphylaxis. These allergies are triggered by the proteins found in tree nuts, and cooking often does not remove or change these proteins. Reactions to cashew and tree nuts can also occur as a consequence of hidden nut ingredients or traces of nuts that may inadvertently be introduced during food processing, handling, or manufacturing, particularly in people of European descent. The shell of the cashew nut contains oil compounds that can cause contact dermatitis similar to poison ivy, primarily resulting from the phenolic lipids, anacardic acid, and cardanol. Due to the possible dermatitis, cashews are typically not sold in the shell to consumers. Readily and inexpensively extracted from the waste shells, cardanol is under research for its potential applications in nanomaterials and biotechnology.


Culinary uses for cashew seeds in snacking and cooking are similar to those for all tree seeds called nuts.
Cashews are commonly used in South Asian cuisine, whole for garnishing sweets or curries, or ground into a paste that forms a base of sauces for curries (e.g., korma), or some sweets (e.g., kaju barfi). It is also used in powdered form in the preparation of several Indian sweets and desserts. In Goan cuisine, both roasted and raw kernels are used whole for making curries and sweets. Cashews are also used in Thai and Chinese cuisines, generally in whole form. In the Philippines, cashew is a known product of Antipolo, and is eaten with suman. The province of Pampanga also has a sweet dessert called turrones de casuy, which is cashew marzipan wrapped in white wafers. In Indonesia, roasted and salted cashews are called kacang mete or kacang mede, while the cashew apple is called jambu monyet (lit. ‘monkey rose apple’).
In the 21st century, cashew cultivation increased in several African countries to meet the demands for manufacturing cashew milk, a plant milk alternative to dairy milk. In Mozambique, bolo polana is a cake prepared using powdered cashews and mashed potatoes as the main ingredients. This dessert is popular in South Africa.


The mature cashew apple can be eaten fresh, cooked in curries, or fermented into vinegar, citric acid or an alcoholic drink. It is also used to make preserves, chutneys and jams in some countries such as India and Brazil. In many countries, particularly within South America, the cashew apple is used to flavor drinks, both alcoholic and nonalcoholic.
In Brazil, cashew fruit juice and the fruit pulp are used in the production of sweets, juice, mixed with alcoholic beverages such as cachaça, and as a flour, milk, or cheese. In Panama, the cashew fruit is cooked with water and sugar for a prolonged time to make a sweet, brown, paste-like dessert called dulce de marañón (marañón being a Spanish name for cashew).
Cashew nuts are more widely traded than cashew apples, because the fruit, unlike the nut, is easily bruised and has a very limited shelf life. Cashew apple juice, however, may be used for manufacturing blended juices.
When consumed, the apple's astringency is sometimes removed by steaming the fruit for five minutes before washing it in cold water. Steeping the fruit in boiling salt water for five minutes also reduces the astringency.
In Cambodia, where the plant is usually grown as an ornamental rather than an economic tree, the fruit is a delicacy and is eaten with salt.


Cashew nutshell liquid (CNSL) or cashew shell oil (CAS registry number 8007-24-7) is a natural resin with a yellowish sheen found in the honeycomb structure of the cashew nutshell, and is a byproduct of processing cashew nuts.  It should not be confused with the edible cashew nut oil, as it is a strong irritant. It is therefore a danger in small-scale processing of the shells, but is a raw material having multiple possible uses. It is used in tropical folk medicine and for anti-termite treatment of timber.  Its composition varies depending on how it is processed.
Cold, solvent-extracted CNSL is mostly composed of anacardic acids (70%), cardol (18%) and cardanol (5%).
Heating CNSL decarboxylates the anacardic acids, producing a technical grade of CNSL that is rich in cardanol. Distillation of this material gives distilled, technical CNSL containing 78% cardanol and 8% cardol (cardol has one more hydroxyl group than cardanol). This process also reduces the degree of thermal polymerization of the unsaturated alkyl-phenols present in CNSL.
Anacardic acid is also used in the chemical industry for the production of cardanol, which is used for resins, coatings, and frictional materials.
These substances are skin allergens, like lacquer and the oils of poison ivy, and they present a danger during manual cashew processing.
This natural oil phenol has interesting chemical structural features that can be modified to create a wide spectrum of biobased monomers. These capitalize on the chemically versatile construct, which contains three functional groups: the aromatic ring, the hydroxyl group, and the double bonds in the flanking alkyl chain. These include polyols, which have recently seen increased demand for their biobased origin and key chemical attributes such as high reactivity, range of functionalities, reduction in blowing agents, and naturally occurring fire retardant properties in the field of rigid polyurethanes, aided by their inherent phenolic structure and larger number of reactive units per unit mass.
CNSL may be used as a resin for carbon composite products.  CNSL-based Novolac is another versatile industrial monomer deriving from cardanol typically used as a reticulating agent for epoxy matrices in composite applications providing good thermal and mechanical properties to the final composite material.


This species is native to the Caribbean: it is found in Brazil, Venezuela, Suriname, Guyana, and on Barbados, Trinidad and Tobago, St. Maarten, Martinique, Dominica, Guadeloupe, Jamaica, Puerto Rico and Haiti.
This species has been introduced to southern Florida, where it can occur in large numbers but is not considered a pest.


Anageshna is a monotypic moth genus of the family Crambidae described by Eugene G. Munroe in 1956. Its only species, Anageshna primordialis, the yellow-spotted webworm, was described by Harrison Gray Dyar Jr. in 1907. It is found in the US states of Alabama, Arkansas, Arizona, Florida, Georgia, Iowa, Illinois, Kansas, Louisiana, Massachusetts, Maryland, Maine, Minnesota, Missouri, Mississippi, North Carolina, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, South Carolina, Texas, Virginia and West Virginia.
The wingspan is about 11 mm. Adults are on wing from August to November.
Hosts plants are unknown.


Europe East to Siberia, Central Asia, Mongolia, China, Tibet, Korea and Japan. Also in Armenia and the Caucasus. In North America South Canada, Washington, Oregon, North Utah, New Mexico, New Jersey, Ohio, North Carolina.


One or two broods are produced each year, and adults can be seen at any time from May to September. This species flies at night and is attracted to light as well as to sugar and nectar-rich flowers.
Flight from June to first half of July. Second generation from latter half of July to September.
The larvae feed on a wide range of plants (see list below). The species overwinters as pupae.


The pintail or northern pintail (Anas acuta) is a duck species with wide geographic distribution that breeds in the northern areas of Europe and across the Palearctic and North America. It is migratory and winters south of its breeding range to the equator. Unusually for a bird with such a large range, it has no geographical subspecies if the possibly conspecific duck Eaton's pintail is considered to be a separate species.
This is a large duck, and the male's long central tail feathers give rise to the species' English and scientific names. Both sexes have blue-grey bills and grey legs and feet. The drake is more striking, having a thin white stripe running from the back of its chocolate-coloured head down its neck to its mostly white undercarriage. The drake also has attractive grey, brown, and black patterning on its back and sides. The hen's plumage is more subtle and subdued, with drab brown feathers similar to those of other female dabbling ducks. Hens make a coarse quack and the drakes a flute-like whistle.
The northern pintail is a bird of open wetlands which nests on the ground, often some distance from water. It feeds by dabbling for plant food and adds small invertebrates to its diet during the nesting season. It is highly gregarious when not breeding, forming large mixed flocks with other species of duck. This duck's population is affected by predators, parasites and avian diseases. Human activities, such as agriculture, hunting and fishing, have also had a significant impact on numbers. Nevertheless, owing to the huge range and large population of this species, it is not threatened globally.


This dabbling duck breeds across northern areas of the Palearctic south to about Poland and Mongolia, and in Canada, Alaska and the Midwestern United States. Mainly in winters south of its breeding range, reaches almost to the equator in Panama, northern sub-Saharan Africa and tropical South Asia. Small numbers migrate to Pacific islands, particularly Hawaii, where a few hundred birds winter on the main islands in shallow wetlands and flooded agricultural habitats. Transoceanic journeys also occur: a bird that was caught and ringed in Labrador, Canada, was shot by a hunter in England nine days later, and Japanese-ringed birds have been recovered from six US states east to Utah and Mississippi. In parts of the range, such as Great Britain and the northwestern United States, the pintail may be present all year.
The northern pintail's breeding habitat is open unwooded wetlands, such as wet grassland, lakesides or tundra. In winter, it will utilise a wider range of open habitats, such as sheltered estuaries, brackish marshes and coastal lagoons. It is highly gregarious outside the breeding season and forms very large mixed flocks with other ducks.


The chestnut teal is commonly distributed in south-eastern and south-western Australia, while vagrants may occur elsewhere. Tasmania and southern Victoria are the species’ stronghold, while vagrants have been found as far north as New Guinea and Lord Howe Island, and as far south as New Zealand.
The chestnut teal prefers coastal estuaries and wetlands, and is indifferent to salinity. This bird is an omnivore.


There are two distinct subspecies of the mottled duck. One subspecies, the Gulf Coast mottled duck (A. f. maculosa), lives on the Gulf of Mexico coast between Alabama and Tamaulipas (Mexico); outside the breeding season, individual birds may venture as far south as Veracruz. The other, the Florida mottled duck (A. f. fulvigula), is resident in central and southern Florida and occasionally strays north to Georgia. The same disjunct distribution pattern was also historically found in the local sandhill cranes. Individuals of both subspecies were introduced into South Carolina in the 1970s and 1980s, where the birds of mixed ancestry have greatly expanded in range, extending through the Atlantic coastal plain of Georgia into northeastern Florida.


The adult mottled duck is 44 to 61 cm (17–24 in) long from head to tail. It has a dark body, lighter head and neck, orange legs and dark eyes. Both sexes have a shiny green-blue speculum (wing patch), which is not bordered with white as with the mallard. Males and females are similar, but the male's bill is bright yellow, whereas the female's is deep to pale orange, occasionally lined with black splotches around the edges and near the base.
The plumage is darker than in female mallards, especially at the tail, and the bill is yellower. In flight, the lack of a white border to the speculum is a key difference. The American black duck is darker than most mottled ducks, and its wing-patch is more purple than blue. The behaviour and voice are the same as the mallard.
Mottled ducks feed by dabbling in shallow water, and grazing on land. They mainly eat plants, but also some mollusks and aquatic insects. The ducks are fairly common within their restricted range; they are resident all-year round and do not migrate. The breeding habitat is coastal marshes. The nest is built on the ground amongst vegetation, such as bull-rush and marsh grass.
Measurements:
Male:
Length: 19.7–22.5 in (50–57 cm)
Weight: 30.9–43.8 oz (880–1,240 g)
Wingspan: 32.7–34.3 in (83–87 cm)
Female:
Length: 18.5–21.0 in (47–53 cm)
Weight: 24.7–40.6 oz (700–1,150 g)
Wingspan: 31.5–327.2 in (80–831 cm)


The Floridian population, which occurs approximately south of Tampa, is separated as the nominate subspecies Anas fulvigula fulvigula and is occasionally called the Florida mottled duck or Florida mallard. It differs from the other subspecies, the Gulf Coast mottled duck (A. f. maculosa) (etymology: maculosa, Latin for "the mottled one"), by being somewhat lighter in color and less heavily marked; while both subspecies are intermediate between female mallards and American black ducks, the Florida mottled duck is closer to the former and the Gulf Coast mottled duck closer to the latter in appearance; this is mainly recognizable in the lighter head being quite clearly separated from the darker breast in Gulf Coast mottled ducks, but much less so in Florida mottled ducks. As the subspecies' ranges do not overlap, these birds can only be confused with female mallards and American black ducks however; particularly female American black ducks are often only reliably separable by their dark purple speculum from mottled ducks in the field.
mtDNA control region sequence data indicates that these birds are derived from ancestral American black ducks, being far more distantly related to the mallard, and that the two subspecies, as a consequence of their rather limited range and sedentary habits, are genetically well distinct already.
As in all members of the "mallardine" clade of ducks, they are able to produce fertile hybrids with their close relatives, the American black duck and the mallard. This has always been so to a limited extent; individuals of the migratory American black ducks which winter in the mottled duck's range may occasionally stay there and mate with the resident species, and for the mallard, which colonized North America later, the same holds true. Genetic tools have been developed in order to robustly classify hybrids and to assess and monitor the genetic dynamics of introgression between the Florida mottled duck and the mallard.
While the resultant gene flow is no cause for immediate concern, habitat destruction and excessive hunting could eventually reduce this species to the point where the hybridization with mallards would threaten to make it disappear as a distinct taxon. This especially applies to the Florida mottled duck, in the fairly small range of which rampant habitat destruction due to urbanization and draining of wetlands has taken place in the last decades; this, in combination with climate change affecting the Everglades, could be sufficient to cause the Florida mottled duck to decline to a point where hunting would have to be restricted or prohibited. At present, these birds too appear to be holding their own, with a population of 50,000-70,000 individuals. While hybridization is common, double white bars above and below the speculum are not a sufficient indicator of hybridization and therefore should not be used to determine genetics.


It can be identified due to the presence of a crimson coloured iris in its eyes. This crimson colour is relatively more prominent in adult males. It is a mottled brown duck with white and green flashes on its wings. Males and females share the same colouration, in contrast to the related chestnut teal, whose male and female are strikingly different. The grey teal has almost identical colouration to the female chestnut teal and the grey can only be distinguished by its lighter coloured neck and paler face. Juveniles are paler than adults, especially on the head. However, they can be identified by a dull brown eye until matured. The bill of the grey teal is a blue-grey colour with dark lining around the edges. Feet are a similar colour to that of the bill being grey. The head of the grey teal can be described as plain/slightly streaked, with a dark crown and cream coloured chin/throat and cheeks.
The eggs of the grey teal are a creamy white colour and are not distinctly speckled. An average egg is 49.3 mm (1.94 in) in length and 35.6 mm (1.40 in) in width.
The grey teal nests near its favoured freshwater lakes and marshes, usually on the ground, but also in tree holes or rabbit burrows.
It is a vocal duck, especially at night. The male gives a soft preep, and the female has a loud quack.
The grey teal is a gregarious species. In Australia it is nomadic, rapidly colonising suitable habitat following rain. In 1957, large numbers fled Australia, moving to New Zealand to escape drought.
Adult grey teal, Anas gracilis, undergo a flightless moult that is not fixed in the year. Before breeding season mature birds, both male and female, will undergo a body moult that excludes the wings. Then after breeding season, both partners will undergo a complete body moult (including wings). According to Janet Kear (2005), in Australia the moult of this species is correlated with climate conditions. Indeed during prolonged wet season birds postpone wing moult in order to extend the breeding one – probably in order to better exploit wetlands resources. This postponement could be explained by the fact that ducks try not to moult and breed at the same time. For some species of birds it is even impossible to do both simultaneously. If we have to draw a tendency we could say that body moult (including wings) generally occurs between the months of January to March when it is late summer or early winter. Juveniles will undergo a complete moult of the entire body other than the wings, occurring in the first autumn or early winter.
It was formerly considered a subspecies of the Sunda teal, as Anas gibberifrons gracilis.
Widespread throughout its large range, the grey teal is evaluated as Least Concern on the IUCN Red List of Threatened Species.


The grey teal can be found as a breeding species in the following places across the globe; Australia, New Zealand, New Guinea and Indonesia. However, it can also be seen in the Solomons and New Caledonia where it is vagrant.


The grey teal is a self-introduced species to New Zealand from Australia, where it is much more abundant. It was rare in New Zealand until the 1950s when several natural events in Australia led to a huge increase in numbers. Now it is a very common waterbird that can be found throughout New Zealand. However, there are areas where the species are more concentrated (larger populations) such as the districts of Hawke's Bay, Waikato, South Auckland and Otago. Grey teal are also more likely to be found in the Canterbury region and more specifically around Lake Ellesmere. Anas gracilis has also been seen wandering in the small New Zealand islands such as Chatham Islands (July 1951, December 1998) or Snares Islands (November 1987). In general the New Zealand grey teal population is smaller than the Australian population.


When establishing a pair-bond, male grey teal will perform a series of displays; some of these include headshakes and head rolls. These displays tend to occur in adolescent birds before breeding season, whereas for mature birds in established pair-bonds courtship rituals are used. This is because grey teal pair-bonds are long term and monogamous, which means they keep the same mate through multiple seasons. Couples stay together all year; however, when late summer moult comes they often join large flocks and stay with them until July. Moreover, “after breeding, [they] often gather at estuaries to feed on exposed mudflats”.
On average, the grey teal starts breeding at one year old. In Australia there is no reproductive season as breeding is linked to rainfall and food abundance. The species had to adapt and breed in shallow temporary water. However, in New Zealand where the climate is more humid, breeding is more seasonal even if it is still related to water level. In terms of seasonality, grey teal will tend to breed in the summer-rainfall period. However, they will also breed at any time after a significant amount of rainfall.  Thus, in New Zealand laying occurs between June and September “but replacement clutches can be laid through to January”. Therefore, their breeding time seldom shows a seasonal pattern.
Nesting is usually solitary for the grey teal; however, sometimes nesting sites will be close together, meaning breeding pairs may be close to one and other. Nests are often found in tree hollows or hidden amongst vegetation on the ground. The grey teal is not known to construct nests other than using material found from its nesting site: grass and down. Females will create a bowl in the ground that they proceed to fill with litter found around the site as well as surrounding the nest/bowl with down. Between 1-7 eggs will be laid in a nest at a time. Nesting time occurs between the months of June-February in South Australia and slightly later in the area of North Australia  due to a slight difference in temperature; whereas in New Zealand grey teal tend to nest between the months of September–November.
During the incubation period, the male will stand guard and protect the female and eggs while she incubates them for 25–31 days.  The clutch (group of eggs) size fluctuates, with an average clutch size being between 6-14 eggs. The laying of each egg is done in approximately 24-hour intervals with laying occurring early in the morning. If a pair loses a brood (amount of chicks hatched at the same time) they will then begin to lay again only after a few weeks. Therefore, some pairs may lay several clutches per season. However, on average the grey teal will lay approximately two broods per season.
Female grey teal will brood young by themselves, however, when necessary (e.g. death of the female) the male will take over the brooding role and raise the ducklings. Male will also often be present at the later stages of brooding as the female will return to incubate/lay her next clutch. After hatching, parents and broods may remain close to each other for a number of weeks; once the young gains flight it then becomes independent. However, siblings will often stick together for a short amount of time once they have left home.
Fledging usually occurs between 35 and 40 days. Before that ducklings are grey-brown with off-white cheeks and underpart. For juveniles, both female and male grey teal become reproductively mature at one-year-old. Therefore the forming of a pair-bonding will commonly occur in the first winter.


The grey teal has a diet mostly consisting of invertebrates from their habitat; these include larva of midges, water beetles, mosquitoes and caddisflies, as well as seeds from aquatic plants present in their habitat. Diet changes according to the locality and time of the year. Thus, in Australia grey teal feed mostly on plant material and especially seeds. It constitutes 87-97% of their diet.
Although insects are eaten throughout the year, their part in the diet increases in spring. Similarly, molluscs and crustaceans are important in the diet only during spring and autumn.
In Australia, the youngest ducklings feed only on insects but the relative amount decreases to only 30% when they are four weeks old.
Grey teal will regularly retrieve their food through the process of either dredging out estuary mudflats or exposed margins of lakeside to filter out food. Dabbling and upending in shallow water areas is another technique used for food retrieval, to collect invertebrates from just below the water surface. To obtain seeds, grey teal will strip them from the aquatic vegetation. During breeding season grey teal will feed strictly in breeding pairs or family parties; however, once the breeding season is over they tend to feed as a flock. In terms of ducklings, they must forage for their own food as there is no feeding from parents that occurs. Grey teal will feed at both morning and night time.


Predators, parasites and disease is an area that has not been particularly well studied in grey teal. However, in Australia, they are considered a game bird due to large population numbers. Therefore hunters and duck shooters are a significant predator of these birds; whereas in New Zealand the grey teal is a protected species. This means that it cannot be hunted for due to low population numbers.
Grey teal ducklings tend to be at higher risk of predation than adults. Other aviator predators pose a threat as they are known to take ducklings out of nests from approaching above. When in the water ducklings are at risk from eels, rats and swamp harriers as they have been known to predate when the ducklings are swimming. Additionally, when adult grey teal are with broods they are at risk to predators such as ferrets and stoats.
A known parasite affecting waterfowl is Sarcocystis, also known as rice breast disease that is caused by a parasitic protozoan. Although this disease usually is asymptomatic (infected but shows no symptoms) if severe the infection can result in weakness, lameness and loss of muscle tissue. With these severe effects, this can increase the likelihood of predation on the infected species, thus increasing its chance of death. No specific cases of Sarcocystis have been found in grey teal; however, it is known that this parasite targets birds and more specifically waterfowl.
The grey teal is one of three ducks known to host the virus Dalvirus anatis.


The mallard is a medium-sized waterfowl species that is often slightly heavier than most other dabbling ducks. It is 50–65 cm (20–26 in) long – of which the body makes up around two-thirds – has a wingspan of 81–98 cm (32–39 in), and weighs 0.7–1.6 kg (1.5–3.5 lb). Among standard measurements, the wing chord is 25.7 to 30.6 cm (10.1 to 12.0 in), the bill is 4.4 to 6.1 cm (1.7 to 2.4 in), and the tarsus is 4.1 to 4.8 cm (1.6 to 1.9 in).
The breeding male mallard is unmistakable, with a glossy bottle-green head and a white collar that demarcates the head from the purple-tinged brown breast, grey-brown wings, and a pale grey belly. The rear of the male is black, with white-bordered dark tail feathers. The bill of the male is a yellowish-orange tipped with black, with that of the female generally darker and ranging from black to mottled orange and brown. The female mallard is predominantly mottled, with each individual feather showing sharp contrast from buff to very dark brown, a coloration shared by most female dabbling ducks, and has buff cheeks, eyebrow, throat, and neck, with a darker crown and eye-stripe.
Both male and female mallards have distinct iridescent purple-blue speculum feathers edged with white, which are prominent in flight or at rest but temporarily shed during the annual summer moult. Upon hatching, the plumage of the duckling is yellow on the underside and face (with streaks by the eyes) and black on the back (with some yellow spots) all the way to the top and back of the head. Its legs and bill are also black. As it nears a month in age, the duckling's plumage starts becoming drab, looking more like the female, though more streaked, and its legs lose their dark grey colouring. Two months after hatching, the fledgling period has ended, and the duckling is now a juvenile. The duckling is able to fly 50–60 days after hatching. Its bill soon loses its dark grey colouring, and its sex can finally be distinguished visually by three factors: 1) the bill is yellow in males, but black and orange in females; 2) the breast feathers are reddish-brown in males, but brown in females; and 3) in males, the centre tail feather (drake feather) is curled, but in females, the centre tail feather is straight. During the final period of maturity leading up to adulthood (6–10 months of age), the plumage of female juveniles remains the same while the plumage of male juveniles gradually changes to its characteristic colours. This change in plumage also applies to adult mallard males when they transition in and out of their non-breeding eclipse plumage at the beginning and the end of the summer moulting period. The adulthood age for mallards is fourteen months, and the average life expectancy is three years, but they can live to twenty.
Several species of duck have brown-plumaged females that can be confused with the female mallard. The female gadwall (Mareca strepera) has an orange-lined bill, white belly, black and white speculum that is seen as a white square on the wings in flight, and is a smaller bird. More similar to the female mallard in North America are the American black duck (A. rubripes), which is notably darker-hued in both sexes than the mallard, and the mottled duck (A. fulvigula), which is somewhat darker than the female mallard, and with slightly different bare-part colouration and no white edge on the speculum.
In captivity, domestic ducks come in wild-type plumages, white, and other colours. Most of these colour variants are also known in domestic mallards not bred as livestock, but kept as pets, aviary birds, etc., where they are rare but increasing in availability.
A noisy species, the female has the deep quack stereotypically associated with ducks. Male mallards make a sound phonetically similar to that of the female, a typical quack, but it is deeper and quieter compared to that of the female. When incubating a nest, or when offspring are present, females vocalise differently, making a call that sounds like a truncated version of the usual quack. This maternal vocalisation is highly attractive to their young. The repetition and frequency modulation of these quacks form the auditory basis for species identification in offspring, a process known as acoustic conspecific identification. In addition, females hiss if the nest or offspring are threatened or interfered with. When taking off, the wings of a mallard produce a characteristic faint whistling noise.
The mallard is a rare example of both Allen's Rule and Bergmann's Rule in birds. Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds, as in case of the Greenland mallard which is larger than the mallards further south. Allen's Rule says that appendages like ears tend to be smaller in polar forms to minimise heat loss, and larger in tropical and desert equivalents to facilitate heat diffusion, and that the polar taxa are stockier overall. Examples of this rule in birds are rare as they lack external ears, but the bill of ducks is supplied with a few blood vessels to prevent heat loss, and, as in the Greenland mallard, the bill is smaller than that of birds farther south, illustrating the rule.
Due to the variability of the mallard's genetic code, which gives it its vast interbreeding capability, mutations in the genes that decide plumage colour are very common and have resulted in a wide variety of hybrids, such as Brewer's duck (mallard × gadwall, Mareca strepera).


The mallard is widely distributed across the Northern and Southern Hemispheres; in North America its range extends from southern and central Alaska to Mexico, the Hawaiian Islands, across the Palearctic, from Iceland and southern Greenland and parts of Morocco (North Africa) in the west, Scandinavia and Britain to the north, and to Siberia, Japan, and South Korea. Also in the east, it ranges to south-eastern and south-western Australia and New Zealand in the Southern hemisphere. It is strongly migratory in the northern parts of its breeding range, and winters farther south. For example, in North America, it winters south to the southern United States and northern Mexico, but also regularly strays into Central America and the Caribbean between September and May. A drake later named "Trevor" attracted media attention in 2018 when it turned up on the island of Niue, an atypical location for mallards.
The mallard inhabits a wide range of habitats and climates, from the Arctic tundra to subtropical regions. It is found in both fresh- and salt-water wetlands, including parks, small ponds, rivers, lakes and estuaries, as well as shallow inlets and open sea within sight of the coastline. Water depths of less than 0.9 metres (3.0 ft) are preferred, with birds avoiding areas more than a few metres deep. They are attracted to bodies of water with aquatic vegetation.


The mallard is omnivorous and very flexible in its choice of food. Its diet may vary based on several factors, including the stage of the breeding cycle, short-term variations in available food, nutrient availability, and interspecific and intraspecific competition. The majority of the mallard's diet seems to be made up of gastropods, insects (including beetles, flies, lepidopterans, dragonflies, and caddisflies), crustaceans, worms, many varieties of seeds and plant matter, and roots and tubers. During the breeding season, male birds were recorded to have eaten 37.6% animal matter and 62.4% plant matter, most notably the grass Echinochloa crus-galli, and nonlaying females ate 37.0% animal matter and 63.0% plant matter, while laying females ate 71.9% animal matter and only 28.1% plant matter. Plants generally make up the larger part of a bird's diet, especially during autumn migration and in the winter.
The mallard usually feeds by dabbling for plant food or grazing; there are reports of it eating frogs. However, in 2017 a flock of mallards in Romania were observed hunting small migratory birds, including grey wagtails and black redstarts, the first documented occasion they had been seen attacking and consuming large vertebrates. It usually nests on a river bank, but not always near water. It is highly gregarious outside of the breeding season and forms large flocks, which are known as "sordes".


Mallards usually form pairs (in October and November in the Northern Hemisphere) until the female lays eggs at the start of the nesting season, which is around the beginning of spring. At this time she is left by the male who joins up with other males to await the moulting period, which begins in June (in the Northern Hemisphere). During the brief time before this, however, the males are still sexually potent and some of them either remain on standby to sire replacement clutches (for female mallards that have lost or abandoned their previous clutch) or forcibly mate with females that appear to be isolated or unattached regardless of their species and whether or not they have a brood of ducklings.

Nesting sites are typically on the ground, hidden in vegetation where the female's speckled plumage serves as effective camouflage, but female mallards have also been known to nest in hollows in trees, boathouses, roof gardens and on balconies, sometimes resulting in hatched offspring having difficulty following their parent to water.
Egg clutches number 8–13 creamy white to greenish-buff eggs free of speckles. They measure about 58 mm (2.3 in) in length and 32 mm (1.3 in) in width. The eggs are laid on alternate days, and incubation begins when the clutch is almost complete. Incubation takes 27–28 days and fledging takes 50–60 days. The ducklings are precocial and fully capable of swimming as soon as they hatch. However, filial imprinting compels them to instinctively stay near the mother, not only for warmth and protection but also to learn about and remember their habitat as well as how and where to forage for food. Though adoptions are known to occur, female mallards typically do not tolerate stray ducklings near their broods, and will violently attack and drive away any unfamiliar young, sometimes going as far as to kill them.
When ducklings mature into flight-capable juveniles, they learn about and remember their traditional migratory routes (unless they are born and raised in captivity). In New Zealand, where mallards are naturalised, the nesting season has been found to be longer, eggs and clutches are larger and nest survival is generally greater compared with mallards in their native range.
In cases where a nest or brood fails, some mallards may mate for a second time in an attempt to raise a second clutch, typically around early-to-mid summer. In addition, mallards may occasionally breed during the autumn in cases of unseasonably warm weather; one such instance of a ‘late’ clutch occurred in November 2011, in which a female successfully hatched and raised a clutch of eleven ducklings at the London Wetland Centre.
During the breeding season, both male and female mallards can become aggressive, driving off competitors to themselves or their mate by charging at them. Males tend to fight more than females, and attack each other by repeatedly pecking at their rival's chest, ripping out feathers and even skin on rare occasions. Female mallards are also known to carry out 'inciting displays', which encourage other ducks in the flock to begin fighting. It is possible that this behaviour allows the female to evaluate the strength of potential partners.
The drakes that end up being left out after the others have paired off with mating partners sometimes target an isolated female duck, even one of a different species, and proceed to chase and peck at her until she weakens, at which point the males take turns copulating with the female. Lebret (1961) calls this behaviour "Attempted Rape Flight", and Stanley Cramp and K.E.L. Simmons (1977) speak of "rape-intent flights". Male mallards also occasionally chase other male ducks of a different species, and even each other, in the same way. In one documented case of "homosexual necrophilia", a male mallard copulated with another male he was chasing after the chased male died upon flying into a glass window. This paper was awarded an Ig Nobel Prize in 2003.
Mallards are opportunistically targeted by brood parasites, occasionally having eggs laid in their nests by redheads, ruddy ducks, lesser scaup, gadwalls, northern shovelers, northern pintails, cinnamon teal, common goldeneyes, and other mallards. These eggs are generally accepted when they resemble the eggs of the host mallard, but the hen may attempt to eject them or even abandon the nest if parasitism occurs during egg laying.


In addition to human hunting, mallards of all ages (but especially young ones) and in all locations must contend with a wide diversity of predators including raptors and owls, mustelids, corvids, snakes, raccoons, opossums, skunks, turtles, large fish, felids, and canids, the last two including domestic ones. The most prolific natural predators of adult mallards are red foxes (which most often pick off brooding females) and the faster or larger birds of prey, e.g. peregrine falcons, Aquila or Haliaeetus eagles. In North America, adult mallards face no fewer than 15 species of birds of prey, from northern harriers (Circus hudsonius) and short-eared owls (Asio flammeus) (both smaller than a mallard) to huge bald (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos), and about a dozen species of mammalian predators, not counting several more avian and mammalian predators who threaten eggs and nestlings.
Mallards are also preyed upon by other waterside apex predators, such as grey herons (Ardea cinerea), great blue herons (Ardea herodias) and black-crowned night herons (Nycticorax nycticorax), the European herring gull (Larus argentatus), the wels catfish (Silurus glanis), and the northern pike (Esox lucius). Crows (Corvus spp.) are also known to kill ducklings and adults on occasion. Also, mallards may be attacked by larger anseriformes such as swans (Cygnus spp.) and geese during the breeding season, and are frequently driven off by these birds over territorial disputes. Mute swans (Cygnus olor) have been known to attack or even kill mallards if they feel that the ducks pose a threat to their offspring. Common loons (Gavia inmer) are similarly territorial and aggressive towards other birds in such disputes, and will frequently drive mallards away from their territory. However, in 2019, a pair of common loons in Wisconsin were observed raising a mallard duckling for several weeks, having seemingly adopted the bird after it had been abandoned by its parents.
The predation-avoidance behaviour of sleeping with one eye open, allowing one brain hemisphere to remain aware while the other half sleeps, was first demonstrated in mallards, although it is believed to be widespread among birds in general.


Since 1998, the mallard has been rated as a species of least concern on the IUCN Red List of Endangered Species. This is because it has a large range–more than 20,000,000 km² (7,700,000 mi²) and because its population is increasing, rather than declining by 30% over ten years or three generations and thus is not warranted a vulnerable rating. Also, the population size of the mallard is very large.
Unlike many waterfowl, mallards have benefited from human alterations to the world – so much so that they are now considered an invasive species in some regions. They are a common sight in urban parks, lakes, ponds, and other human-made water features in the regions they inhabit, and are often tolerated or encouraged in human habitat due to their placid nature towards humans and their beautiful and iridescent colours. While most are not domesticated, mallards are so successful at coexisting in human regions that the main conservation risk they pose comes from the loss of genetic diversity among a region's traditional ducks once humans and mallards colonise an area. Mallards are very adaptable, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development. The release of feral mallards in areas where they are not native sometimes creates problems through interbreeding with indigenous waterfowl. These non-migratory mallards interbreed with indigenous wild ducks from local populations of closely related species through genetic pollution by producing fertile offspring. Complete hybridisation of various species of wild duck gene pools could result in the extinction of many indigenous waterfowl. The mallard itself is the ancestor of most domestic ducks, and its naturally evolved wild gene pool gets genetically polluted in turn by the domestic and feral populations.
Over time, a continuum of hybrids ranging between almost typical examples of either species develop; the speciation process is beginning to reverse itself. This has created conservation concerns for relatives of the mallard, such as the Hawaiian duck, the New Zealand grey duck (A. s. superciliosa) subspecies of the Pacific black duck, the American black duck, the mottled duck, Meller's duck, the yellow-billed duck, and the Mexican duck, in the latter case even leading to a dispute as to whether these birds should be considered a species (and thus entitled to more conservation research and funding) or included in the mallard species. Ecological changes and hunting have also led to a decline of local species; for example, the New Zealand grey duck population declined drastically due to overhunting in the mid-20th century. Hybrid offspring of Hawaiian ducks seem to be less well adapted to native habitat, and using them in re-introduction projects apparently reduces success. In summary, the problems of mallards "hybridising away" relatives is more a consequence of local ducks declining than of mallards spreading; allopatric speciation and isolating behaviour have produced today's diversity of mallard-like ducks despite the fact that, in most, if not all, of these populations, hybridisation must have occurred to some extent.


Mallards are causing severe "genetic pollution" to South Africa's biodiversity by breeding with endemic ducks even though the Agreement on the Conservation of African-Eurasian Migratory Waterbirds – an agreement to protect the local waterfowl populations – applies to the mallard as well as other ducks. The hybrids of mallards and the yellow-billed duck are fertile, capable of producing hybrid offspring. If this continues, only hybrids occur and in the long term result in the extinction of various indigenous waterfowl. The mallard can crossbreed with 63 other species, posing a severe threat to indigenous waterfowl's genetic integrity. Mallards and their hybrids compete with indigenous birds for resources, including nest sites, roosting sites, and food.
Availability of mallards, mallard ducklings, and fertilised mallard eggs for public sale and private ownership, either as poultry or as pets, is currently legal in the United States, except for the state of Florida, which has currently banned domestic ownership of mallards. This is to prevent hybridisation with the native mottled duck.
The mallard is considered an invasive species in Australia and New Zealand, where it competes with the Pacific black duck (known as the grey duck locally in New Zealand) which was over-hunted in the past. There, and elsewhere, mallards are spreading with increasing urbanisation and hybridising with local relatives.
The eastern or Chinese spot-billed duck is currently introgressing into the mallard populations of the Primorsky Krai, possibly due to habitat changes from global warming. The Mariana mallard was a resident allopatric population – in most respects a good species – apparently initially derived from mallard-Pacific black duck hybrids; unfortunately, it became extinct in the late 20th century.
The Laysan duck is an insular relative of the mallard, with a very small and fluctuating population. Mallards sometimes arrive on its island home during migration, and can be expected to occasionally have remained and hybridised with Laysan ducks as long as these species have existed. However, these hybrids are less well adapted to the peculiar ecological conditions of Laysan Island than the local ducks, and thus have lower fitness. Laysan ducks were found throughout the Hawaiian archipelago before 400 AD, after which they suffered a rapid decline during the Polynesian colonisation. Now, their range includes only Laysan Island. It is one of the successfully translocated birds, after having become nearly extinct in the early 20th century.


This duck is a resident throughout Pakistan and India in freshwater wetlands. They tend to avoid very large patches of open water and prefer medium-sized wetlands with vegetation cover. Some individuals may however migrate as a bird ringed at Bharatpur in Rajasthan on 5 December 1969 was recovered near Novosibirsk in August 1970. It is quite gregarious outside the breeding season and forms small flocks. The northernmost populations have expanded their range northwards by more than 500 km since the early 20th century, possibly in reaction to global warming.


It is a bird of freshwater lakes and marshes in fairly open country and feeds by dabbling for plant food mainly in the evening or at night. The breeding season varies with rainfall and water condition but is July to September in northern India and November to December in southern India. Multiple broods may be raised. It nests on the ground hidden within in vegetation near water, and lays 8-14 eggs. Nests have sometimes been seen on tree branches covered by creepers. Incubation begins after the last egg is laid (allowing the chicks to hatch simultaneously) and the young hatch after about 24 days. The chicks are black with a yellow back and resemble those of mallards but with a wider eyestripe.
Both the male and female have calls similar to that of the mallard.  Mallards and eastern spot-billed ducks have been known to hybridize in the wild in eastern Russia and their genetic closeness has been examined in many studies. Indian spot-billed ducks feed on plants, including crops such as rice, as well as invertebrates including snails. Through snails such as Lymnaea luteola, they also get infected by cercarian trematodes such as Echinoparyphium bagulai. Adult trematodes emerge from the duck after about 21 days. Other trematodes recorded in the species include Psilochasmus oxyurus while helminths include Opisthorchis obsequens, Notocotylus babai, N. linearis, Echinoparyphium clerci, Amidostomum skrjabini, and Hymenolepis wardlei.
They are seen isolated from other species and usually in pairs or small groups and when disturbed they can take off easily and nearly vertically from the water. They were hunted extensively in British India, noted for their excellent taste. When shot at, especially when in moult, they are known to dive and remain underwater to evade capture. A local name for it was "gheret-pai" or "garam-pai". In southern India, a method of hunting involved using floating bundles of rushes on which the hunters lay in wait. Natural predators of the ducks include birds of prey and terrestrial predators including pythons and otters.


The American black duck (Anas rubripes) is a large dabbling duck in the family Anatidae. It was described by William Brewster in 1902. It is the heaviest species in the genus Anas, weighing 720–1,640 g (1.59–3.62 lb) on average and measuring 54–59 cm (21–23 in) in length with an 88–95 cm (35–37 in) wingspan. It somewhat resembles the female and eclipse male mallard in coloration, but has a darker plumage. The male and female are generally similar in appearance, but the male's bill is yellow while the female's is dull green with dark marks on the upper mandible. It is native to eastern North America. During the breeding season, it is usually found in coastal and freshwater wetlands from Saskatchewan to the Atlantic in Canada and the Great Lakes and the Adirondacks in the United States. It is a partially migratory species, mostly wintering in the east-central United States, especially in coastal areas.
It interbreeds regularly and extensively with the mallard, to which it is closely related. The female lays six to fourteen oval eggs, which have smooth shells and come in varied shades of white and buff green. Hatching takes 30 days on average. Incubation usually takes 25 to 26 days, with both sexes sharing duties, although the male usually defends the territory until the female reaches the middle of her incubation period. It takes about six weeks to fledge. Once the eggs hatch, the hen leads the brood to rearing areas with abundant invertebrates and vegetation.
The American black duck is considered to be a species of least concern by the International Union for Conservation of Nature (IUCN). It has long been valued as a game bird. Habitat loss due to drainage, global warming, filling of wetlands due to urbanization and rising sea levels are major reasons for the declining population of the American black duck. The United States Fish and Wildlife Service has been purchasing and managing the habitat of this species in many areas to support the migratory stopover, wintering and breeding populations. The Atlantic Coast Joint Venture also protects habitat through restoration and land acquisition projects, mostly within their wintering and breeding areas.


American ornithologist William Brewster described the American black duck as Anas obscura rubripes, for "red-legged black duck", in his landmark article "An undescribed form of the black duck (Anas obscura)," in The Auk in 1902, to distinguish between the two kinds of black ducks found in New England. One of them was described as being comparatively small, with brownish legs and an olivaceous or dusky bill, and the other as being comparatively larger, with a lighter skin tone, bright red legs and a clear yellow bill. The larger of the two was described as Anas obscura by the German naturalist Johann Friedrich Gmelin in 1789 in the 13th edition of the Systema Naturae, Part 2, and he based it on the "Dusky Duck" of Welsh naturalist Thomas Pennant. The current scientific name, Anas rubripes, is derived from Latin, with Anas meaning "duck" and rubripes coming from ruber, "red", and pes, "foot".
Pennant, in Arctic Zoology, Volume 2, described this duck as coming "from the province of New York" and having "a long and narrow dusky bill, tinged with blue: chin white: neck pale brown, streaked downwards with dusky lines." In a typical obscura, characteristics such as greenish black, olive green or dusky olive bill; olivaceous brown legs with at most one reddish tinge; the nape and pileum nearly uniformly dark; spotless chin and throat; fine linear and dusky markings on the neck and sides of the head, rather than blackish, do not vary with age or season.


The American black duck is an omnivorous species with a diverse diet. It feeds by dabbling in shallow water and grazing on land. Its plant diet primarily includes a wide variety of wetland grasses and sedges, and the seeds, stems, leaves and root stalks of aquatic plants, such as eelgrass, pondweed and smartweed. Its animal diet includes mollusks, snails, amphipods, insects, mussels and small fishes.
During the breeding season, the diet of the American black duck consists of approximately 80% plant food and 20% animal food. The animal food diet increases to 85% during winter. During nesting, the proportion of invertebrates increases. Ducklings mostly eat water invertebrates for the first 12 days after hatching, including aquatic snowbugs, snails, mayflies, dragonflies, beetles, flies, caddisflies and larvae. After this, they shift to seeds and other plant food.


The apex nest predators of the American black duck include American crows, gulls and raccoons, especially in tree nests. Hawks and owls are also major predators of adults. Bullfrogs and snapping turtles eat many ducklings. Ducklings often catch diseases caused by protozoan blood parasites transmitted by bites of insects such as blackflies. They are also vulnerable to lead shot poisoning, known as plumbism, due to their bottom-foraging food habits.


The Pacific black duck is mainly vegetarian, feeding on seeds of aquatic plants. This diet is supplemented with small crustaceans, molluscs and aquatic insects. Food is obtained by 'dabbling', where the bird plunges its head and neck underwater and upends, raising its rear end vertically out of the water. Occasionally, food is sought on land in damp grassy areas.


The Pacific black duck has declined sharply in numbers in New Zealand and several Australian islands due to competition from and hybridisation with the introduced mallard. Rhymer et al. (1994) say their data "points to the eventual loss of identity of the grey duck as a separate species in New Zealand, and the subsequent dominance of a hybrid swarm akin to the Mariana Mallard." Studies of their three species of parasitic feather lice support this prediction. This same impact is occurring in many areas of Australia, Tasmania and Adelaide in particular.
It was assumed that far more mallard drakes mate with grey duck females than vice versa based on the fact that most hybrids show a mallard-type plumage, but this is not correct; it appears that the mallard phenotype is dominant, and that the degree to which species contributed to a hybrid's ancestry cannot be determined from the plumage. The main reasons for displacement of the grey duck seem to be physical dominance of the larger mallards, combined with a marked population decline of the grey duck due to overhunting in the mid-20th century.