The plant prefers a well-drained soil, but supports a poor soil. Exposure to full sun is preferable, but it supports partial shade. It does not like to be moved. It can be multiplied by sowing (flowering under 3 to 4 years) or division of tufts. It tolerates drought once well installed, but watering is preferable in case of long dry periods. It overwinters as a stump and therefore completely disappears during the cold months. Contrary to popular belief, this species can withstand wind, frost and cold up to −15 °C provided that the strains are protected for the first two years with mulching.
Young shoots need to be protected from slugs and snails. A contribution of 2 or 3 handfuls of wood ash around the stump in the spring will push the gastropods a few days and make a good contribution of potash.


The species is naturalised in Australia, New Zealand and the Isles of Scilly. It is reportedly naturalized in Madeira, the Canary Islands, Eritrea, Ethiopia, St. Helena,  Norfolk Island, Mexico, Honduras, Costa Rica and Tristan da Cunha.
Agapanthus praecox  subsp. orientalis is highly regarded for being tough in sun and heat, long-flowering, and is a favourite for many councils in Australia for the landscaping of roads and other public areas which do not get watered. The plant is still widely planted but in some areas it is considered a weed, and planting has been discontinued, although it is not generally regarded as highly invasive.


Agastache foeniculum (blue giant hyssop; syn. Agastache anethiodora (Nutt.) Britton), commonly called anise hyssop, blue giant hyssop, Fragrant giant hyssop, or the lavender giant hyssop, is a species of perennial plant in the mint family, (Lamiaceae).  This plant is native to much of north-central and northern North America, notably the Great Plains and other prairies. It is tolerant of deer and drought, and also attracts hummingbirds, butterflies, bumblebees, honey bees, carpenter bees, and night flying moths.
Anise hyssop is in the same family as hyssop (the mint family Lamiaceae), but they are not closely related. Hyssop (Hyssopus) is a genus of about 10–12 species of herbaceous or semi-woody plants native from the east Mediterranean to central Asia.


This species grows from 2 ft (61 cm) to 4 ft (120 cm) tall and 1 ft (30 cm) wide, in a clump-like, upright shape, with flowers appearing in showy verticillasters, or false whorls, and occasionally branching at the apex. The leaves have an oval, toothed shape with a white tint underneath. The plant blooms in June to September with bright lavender flowers that become more colorful near the tip. One plant may produce upwards of 90,000 individual flowers. The root system produces a taproot.


Anise hyssop is considered one of the premier plants for feeding pollinators. The 1969 edition of the Rodale's Encyclopedia of Organic Gardening claims that one acre planted in anise hyssop can support 100 honeybee hives, the flowers blooming for a very long season, often from June until frost and during the time it blooms, one can see bees on the flowers from the morning until dusk. A horticultural writer has claimed that the many flowers of the plant provide forage for bees, butterflies and hummingbirds.


Anise hyssop was used medicinally by Native Americans for cough, fevers, wounds, diarrhea. The soft, anise-scented leaves are used as a seasoning, as a tea, in potpourri, and can be crumbled in salad. The purple flower spike is favored by bees who make a light fragrant honey from the nectar.


Agathis australis, commonly known by its Māori name kauri (['kɑːʉɾi]), is a coniferous tree in the family Araucariaceae, found north of 38°S in the northern regions of New Zealand's North Island.
It is the largest (by volume) but not tallest species of tree in New Zealand, standing up to 50 m tall in the emergent layer above the forest's main canopy. The tree has smooth bark and small narrow leaves. Other common names to distinguish A. australis from other members of the genus are southern kauri and New Zealand kauri.
Kauri forests are among the most ancient in the world. The antecedents of the kauri appeared during the Jurassic period (between 190 and 135 million years ago). Although the kauri is among the most ancient trees in the world, it has developed a unique niche in the forest. With its novel soil interaction and regeneration pattern it can compete with the more recently evolved and faster growing angiosperms. Because it is such a conspicuous species, forest containing kauri is generally known as kauri forest, although kauri need not be the most abundant tree. In the warmer northern climate, kauri forests have a higher species richness than those found further south.  Kauri even act as a foundation species that modify the soil under their canopy to create unique plant communities.


Scottish botanist David Don described the species as Dammara australis.
Agathis is derived from Greek and means 'ball of twine', a reference to the shape of the male cones, which are also known by the botanical term stroboli.
Australis means 'southern'.


The young plant grows straight upwards and has the form of a narrow cone with branches going out along the length of the trunk. However, as it gains in height, the lowest branches are shed, preventing vines from climbing. By maturity, the top branches form an imposing crown that stands out over all other native trees, dominating the forest canopy.
The flaking bark of the kauri tree defends it from parasitic plants, and accumulates around the base of the trunk. On large trees it may pile up to a height of 2 m or more. The kauri has a habit of forming small clumps or patches scattered through mixed forests.
Kauri leaves are 3 to 7 cm long and 1 cm broad, tough and leathery in texture, with no midrib; they are arranged in opposite pairs or whorls of three on the stem. The seed cones are globose, 5 to 7 cm diameter, and mature 18 to 20 months after pollination; the seed cones disintegrate at maturity to release winged seeds, which are then dispersed by the wind. A single tree produces both male and female seed cones. Fertilisation of the seeds occurs by pollination, which may be driven by the same or another tree's pollen.


Agathis australis can attain heights of 40 to 50 metres and trunk diameters big enough to rival Californian sequoias at over 5 metres. The largest kauri trees did not attain as much height or girth at ground level but contain more timber in their cylindrical trunks than comparable Sequoias with their tapering stems.
The largest recorded specimen was known as The Great Ghost and grew in the mountains at the head of the Tararu Creek, which drains into the Hauraki Gulf just north of the mouth of the Waihou River (Thames). Thames Historian Alastair Isdale says the tree was 8.54 metres in diameter, and 26.83 metres in girth. It was consumed by fire c.1890.
A kauri tree at Mill Creek, Mercury Bay, known as Father of the Forests was measured in the early 1840s as 22 metres in circumference and 24 metres to the first branches. It was recorded as being killed by lightning in that period.
Another huge tree, Kairaru, had a girth of 20.1 metres and a columnar trunk free of branches for 30.5 metres as measured by a Crown Lands ranger, Henry Wilson, in 1860. It was on a spur of Mt Tutamoe about 30 km south of Waipoua Forest near Kaihau. It was destroyed in the 1880s or 1890s when a series of huge fires swept the area.
Other trees far larger than living kauri have been noted in other areas. Rumors of stumps up to 6 metres are sometimes suggested in areas such as the Billygoat Track above the Kauaeranga Valley near Thames. However, there is no good evidence for these (e.g., a documented measurement or a photograph with a person for scale).
Given that over 90 per cent of the area of kauri forest standing before 1000AD was destroyed by about 1900, it is not surprising that recent records are of smaller, but still very large trees. Two large kauri fell during tropical storms in the 1970s. One of these was Toronui, in Waipoua Forest. Its diameter was larger than that of Tane Mahuta and its clean bole larger than that of Te Matua Ngahere, and by forestry measurements was the largest standing. Another tree, Kopi, in Omahuta Forest near the standing Hokianga kauri, was the third largest with a height of 56.39 metres (185') and a diameter of 4.19 metres (13.75'). It fell in 1973. Like many ancient kauri both trees were partly hollow.


In general over the lifetime of the tree the growth rate tends to increase, reach a maximum, then decline. A 1987 study measured mean annual diameter increments ranging from 1.5 to 4.6 mm per year with an overall average of 2.3 mm per year. This is equivalent to 8.7 annual rings per centimetre of core, said to be half the commonly quoted figure for growth rate. The same study found only a weak relationship between age and diameter. The growth of kauri in planted and second-growth natural forests has been reviewed and compared during the development of growth and yield models for the species. Kauri in planted forests were found to have up to 12 times the volume productivity than those in natural stands at the same age.
Individuals in the same 10 cm diameter class may vary in age by 300 years, and the largest individual on any particular site is often not the oldest. Trees can normally live longer than 600 years. Many individuals probably exceed 1000 years, but there is no conclusive evidence that trees can exceed 2000 years in age. By combining tree ring samples from living kauri, wooden buildings, and preserved swamp wood, a dendrochronology has been created which reaches back 4,500 years, the longest tree ring record of past climate change in the southern hemisphere.  One 1700 year old swamp wood kauri that dates to approximately 42,000 years ago contains fine-scale carbon-14 fluctuations in its rings that may be reflective of the most recent magnetic field flip of the earth.


One of the defining aspects of the kauri tree's unique ecological niche is its relationship with the soil below. Much like podocarps, it feeds in the organic litter near the surface of the soil through fine root hairs. This layer of the soil is composed of organic matter derived from falling leaves and branches as well as dead trees, and is constantly undergoing decomposition. On the other hand, broadleaf trees such as māhoe derive a good fraction of their nutrition in the deeper mineral layer of the soil. Although its feeding root system is very shallow, it also has several downwardly directed peg roots which anchor it firmly in the soil. Such a solid foundation is necessary to prevent a tree the size of a kauri from blowing over in storms and cyclones.
The litter left by kauri is much more acidic than most trees, and as it decays similarly acidic compounds are liberated. In a process known as leaching, these acidic molecules pass through the soil layers with the help of rainfall, and release other nutrients trapped in clay such as nitrogen and phosphorus. This leaves these important nutrients unavailable to other trees, as they are washed down into deeper layers. This process is known as podsolization, and changes the soil colour to a dull grey. For a single tree, this leaves an area of leached soil beneath known as a cup podsol. This leaching process is important for kauri's survival as it competes with other species for space.
Leaf litter and other decaying parts of a kauri decompose much more slowly than those of most other species. Besides its acidity, the plant also bears substances such as waxes and phenols, most notably tannins, that are harmful to microorganisms. This results in a large buildup of litter around the base of a mature tree in which its own roots feed. As with most perennials, these feeding roots also house a symbiotic fungi known as mycorrhiza which increase the plant's efficiency in taking up nutrients. In this mutualistic relationship, the fungus derives its own nutrition from the roots. In its interactions with the soil, kauri is thus able to starve its competitors of much needed nutrients and compete with much younger lineages.


In terms of local topography, kauri is far from randomly dispersed. As mentioned above, kauri relies on depriving its competitors of nutrition in order to survive. However, one important consideration not discussed thus far is the slope of the land. Water on hills flows downward by the action of gravity, taking with it the nutrients in the soil. This results in a gradient from nutrient poor soil at the top of slopes to nutrient rich soils below. As nutrients leached are replaced by aqueous nitrates and phosphates from above, the kauri tree is less able to inhibit the growth of strong competitors such as angiosperms. In contrast, the leaching process is only enhanced on higher elevation. In Waipoua Forest this is reflected in higher abundances of kauri on ridge crests, and greater concentrations of its main competitors, such as taraire, at low elevations. This pattern is known as niche partitioning, and allows more than one species to occupy the same area. Those species which live alongside kauri include tawari, a montane broadleaf tree which is normally found in higher altitudes, where nutrient cycling is naturally slow.


Kauri is found growing in its natural ecosystem north of 38°S latitude. Its southern limit stretches from the Kawhia Harbour in the west to the eastern Kaimai Range.
However, its distribution has changed greatly over geological time because of climate change. This is shown in the recent Holocene epoch by its migration southwards after the peak of the last ice age. During this time when frozen ice sheets covered much of the world's continents, kauri was able to survive only in isolated pockets, its main refuge being in the very far north. Radiocarbon dating is one technique used by scientists to uncover the history of the tree's distribution, with stump kauri from peat swamps used for measurement. The coldest period in recent times occurred about 15,000 to 20,000 years ago, during which time kauri was apparently confined north of Kaitaia, near the northernmost point of the North Island, North Cape. Kauri requires a mean temperature of 17 °C or more for most of the year. The tree's retreat can be used as a proxy for temperature changes during this period. While not present in modern days, the Aupouri Peninsula in the far north was a refuge for kauri, as large quantities of kauri gum were present in the soils.
It remains unclear whether kauri recolonised the North Island from a single refuge in the far north or from scattered pockets of isolated stands that managed to survive despite climatic conditions. It spread south through Whangārei, past Dargaville and as far south as Waikato, attaining its peak distribution during the years 3000 BP to 2000 BP. There is some suggestion that it has receded somewhat since then, which may indicate temperatures have declined slightly. During the peak of its movement southwards, it was traveling as fast as 200 metres per year. Its southward spread seems relatively rapid for a tree that can take a millennium to reach complete maturity. This can be explained by its life history pattern.
Kauri relies on wind for pollination and seed dispersal, while many other native trees have their seeds carried large distances by frugivores (animals which eat fruit) such as the kererū (native pigeon). However, kauri trees can produce seeds while relatively young, taking only 50 years or so before giving rise to their own offspring. This trait makes them somewhat like a pioneer species, despite the fact that their long lifespan is characteristic of K-selected species. In good conditions, where access to water and sunlight are above average, diameters in excess of 15 centimetres and seed production can occur inside 15 years.


Just as the niche of kauri is differentiated through its interactions with the soil, it also has a separate regeneration 'strategy' compared to its broadleaf neighbours. The relationship is very similar to the podocarp-broadleaf forests further south. Kauri demand much more light and require larger gaps to regenerate than such broadleaf trees as puriri and kohekohe that show far more shade tolerance. Unlike kauri, these broadleaf species can regenerate in areas where lower levels of light reach ground level, for example from a single branch falling off. Kauri trees must therefore remain alive long enough for a large disturbance to occur, allowing them sufficient light to regenerate. In areas where large amounts of forest are destroyed, such as by logging, kauri seedlings are able to regenerate much more easily due not only to increased sunlight, but their relatively strong resistance to wind and frosts. Kauri occupy the emergent layer of the forest, where they are exposed to the effects of the weather; however, the smaller trees that dominate the main canopy are sheltered both by the emergent trees above and by each other. Left in open areas without protection, these smaller trees are far less capable of regenerating.
When there is a disturbance severe enough to favour their regeneration, kauri trees regenerate en masse, producing a generation of trees of similar age after each disturbance. The distribution of kauri allows researchers to deduce when and where disturbances have occurred, and how large they may have been; the presence of abundant kauri may indicate that an area is prone to disturbance. Kauri seedlings can still occur in areas with low light but mortality rates increase for such seedlings, and those that survive self-thinning and grow to sapling stage tend to be found in higher light environments.
During periods with less disturbance kauri tends to lose ground to broadleaf competitors which can better tolerate shaded environments. In the complete absence of disturbance, kauri tends to become rare as it is excluded by its competitors. Kauri biomass tends to decrease during such times, as more biomass becomes concentrated in angiosperm species like towai. Kauri trees also tend to become more randomly distributed in age, with each tree dying at a different point in time, and regeneration gaps becoming rare and sporadic. Over thousands of years these varying regeneration strategies produce a tug of war effect where kauri retreats uphill during periods of calm, then takes over lower areas briefly during mass disturbances. Although such trends cannot be observed in a human lifetime, research into current patterns of distribution, behavior of species in experimental conditions, and study of pollen sediments (see palynology) have helped shed light on the life history of kauri.
Kauri seeds may generally be taken from mature cones in late March. Each scale on a cone contains a single winged seed approximately 5 mm by 8 mm and attached to a thin wing perhaps half as large again. The cone is fully open and dispersed within only two to three days of starting.
Studies show that kauri develop root grafts through which they share water and nutrients with neighbours of the same species.


Heavy logging, which began around 1820 and continued for a century, has considerably decreased the number of kauri trees. It has been estimated that before 1840, the kauri forests of northern New Zealand occupied at least 12,000 square kilometres. The British Royal Navy sent four vessels, HMS Coromandel (1821), HMS Dromedery (1821), HMS Buffalo (1840), and HMS Tortoise (1841) to gather kauri-wood spars.
By 1900, less than 10 per cent of the original kauri survived. By the 1950s this area had decreased to about 1,400 square kilometres in 47 forests depleted of their best kauri. It is estimated that today, there is 4 per cent of uncut forest left in small pockets.
Estimates are that around half of the timber was accidentally or deliberately burnt. More than half of the remainder had been exported to Australia, Britain, and other countries, while the balance was used locally to build houses and ships. Much of the timber was sold for a return sufficient only to cover wages and expenses. From 1871 to 1895 the receipts indicate a rate of about 8 shillings (around NZ$20 in 2003) per 100 superficial feet (34 shillings/m³).
The Government continued to sell large areas of kauri forests to sawmillers who, under no restrictions, took the most effective and economical steps to secure the timber, resulting in much waste and destruction. At a sale in 1908 more than 5,000 standing kauri trees, totalling about 20,000,000 superficial feet (47,000 m³), were sold for less than £2 per tree (£2 in 1908 equates to around NZ$100 in 2003). It is said that in 1890 the royalty on standing timber fell in some cases to as low as twopence (NZ$0.45 in 2003) per 100 superficial feet (8 pence/m³), though the expense of cutting and removing it to the mills was typically great due to the difficult terrain where they were located.
Probably the most controversial kauri logging decision in the last century was that of the National Government to initiate clear fell logging of the Warawara state forest (North of the Hokianga) in the late 1960s. This created a national outcry as this forest contains the second largest volume of kauri after the Waipoua forest and was until that time, essentially unlogged (Adams, 1980). The plan also involved considerable cost, requiring a long road to be driven up a steep high plateau into the heart of the protected area. Because the stands of kauri were dense, the ecological destruction in the affected plateau area (approximately a fifth of the forest by area, and a quarter by volume of timber) was essentially complete (as of the early 1990s most of the affected area contained a thick covering of native grasses with little or no kauri regeneration). Logging was stopped in fulfillment of an election pledge by the Labour Government of 1972. When the National Party was reelected in 1975, the ban on kauri logging in the Warawara remained in place, but was soon replaced by policies encouraging the logging of giant tōtara and other podocarps in the central North Island. The outcry over the Warawara was an important stepping stone towards the legal protection of the small percentage of remaining virgin kauri-podocarp forest in New Zealand's Government-owned forests.


Although today its use is far more restricted, in the past the size and strength of kauri timber made it a popular wood for construction and ship building, particularly for masts of sailing ships because of its parallel grain and the absence of branches for much of its height. Kauri crown and stump wood was much appreciated for its beauty, and was sought after for ornamental wood panelling as well as high-end furniture. Although not as highly prized, the light colour of kauri trunk wood made it also well-suited for more utilitarian furniture construction, as well as for use in the fabrication of cisterns, barrels, bridge construction material, fences, moulds for metal forges, large rollers for the textile industry, railway sleepers and cross bracing for mines and tunnels.
In the late 19th and early 20th centuries Kauri gum (semi-fossilised kauri resin) was a valuable commodity, particularly for varnish, spurring the development of a gum-digger industry.
Today, the kauri is being considered as a long-term carbon sink. This is because estimates of the total carbon content in living above ground biomass and dead biomass of mature kauri forest are the second highest of any forest type recorded anywhere in the world. The estimated total carbon capture is up to nearly 1000 tones per hectare. In this capacity, kauri are bettered only by mature  Eucalyptus regnans forest, and are far higher than any tropical or boreal forest type yet recorded. It is also conjectured that the process of carbon capture does not reach equilibrium, which along with no need of direct maintenance, makes kauri forests a potentially attractive alternative to short rotation forestry options such as Pinus radiata.


Technical specifications
Moisture content of dried wood: 12 per cent
Density of wood: 560 kg/m³
Tensile strength: 88 MPa
Modulus of elasticity: 9.1 GPa
After felled kauri wood dries to a 12 per cent moisture content, the tangential contraction is 4.1 per cent and the radial contraction is 2.3 per cent.
Kauri is considered a first rate timber. The whiter sapwood is generally slightly lighter in weight. Kauri is not highly resistant to rot and when used in boatbuilding must be protected from the elements with paint, varnish or epoxy to avoid rot. Its popularity with boatbuilders is due to its very long, clear lengths, its relatively light weight and its beautiful sheen when oiled or varnished. Kauri wood planes and saws easily. Its wood holds screws and nails very well and does not readily split, crack, or warp.   Kauri wood darkens with age to a richer golden brown colour. Very little New Zealand kauri is now sold, and the most commonly available kauri in New Zealand is Fiji kauri, which is very similar in appearance but lighter in weight.


Prehistoric kauri forests have been preserved in waterlogged soils as swamp kauri. A considerable number of kauri have been found buried in salt marshes, resulting from ancient natural changes such as volcanic eruptions, sea-level changes and floods. Such trees have been radiocarbon dated to 50,000 years ago or older. The bark and the seed cones of the trees often survive together with the trunk, although when excavated and exposed to the air, these parts undergo rapid deterioration. The quality of the disinterred wood varies. Some is in good shape, comparable to that of newly felled kauri, although often lighter in colour. The colour can be improved by the use of natural wood stains to heighten the details of the grain. After a drying process, such ancient kauri can be used for furniture, but not for construction.


The small remaining pockets of kauri forest in New Zealand have survived in areas that were not subjected to burning by Māori and were too inaccessible for European loggers. The largest area of mature kauri forest is Waipoua Forest in Northland. Mature and regenerating kauri can also be found in other National and Regional Parks such as Puketi and Omahuta Forests in Northland, the Waitākere Ranges near Auckland, and Coromandel Forest Park on the Coromandel Peninsula.
The importance of Waipoua Forest in relation to the kauri was that it remained the only kauri forest retaining its former virgin condition, and that it was extensive enough to give reasonable promise of permanent survival. On 2 July 1952 an area of over 80 km² of Waipoua was proclaimed a forest sanctuary after a petition to the Government.
The zoologist William Roy McGregor was one of the driving forces in this movement, writing an 80-page illustrated pamphlet on the subject, which proved an effective manifesto for conservation.
Along with the Warawara to the North, Waipoua Forest contains three quarters of New Zealand's remaining kauri. Kauri Grove on the Coromandel Peninsula is another area with a remaining cluster of kauri, and includes the Siamese Kauri, two trees with a conjoined lower trunk.
In 1921 a philanthropic Cornishman named James Trounson sold to the Government for £40,000, a large area adjacent to a few acres of Crown land and said to contain at least 4,000 kauri trees. From time to time Trounson gifted additional land, until what is known as Trounson Park comprised a total of 4 km².
The most famous specimens are Tāne Mahuta and Te Matua Ngahere in Waipoua Forest. These two trees have become tourist attractions because of their size and accessibility. Tane Mahuta, named after the Māori forest god, is the biggest existing kauri with a girth of 13.77 metres (45.2 feet), a trunk height of 17.68 metres (58.0 feet), a total height of 51.2 metres (168 feet) and a total volume including the crown of 516.7 cubic metres (18,247 cubic feet). Te Matua Ngahere, which means 'Father of the Forest', is smaller but stouter than Tane Mahuta, with a girth (circumference) of 16.41 m (53.8 ft). Important note: all the measurements above were taken in 1971.
Kauri is common as a specimen tree in parks and gardens throughout New Zealand, prized for the distinctive look of young trees, its low maintenance once established (although seedlings are frost tender).


Kauri dieback was observed in the Waitākere Ranges caused by Phytophthora cinnamomi in the 1950s,  again on  Great Barrier Island in 1972 linked to a different pathogen, Phytophthora agathidicida and subsequently spread to kauri forest on the mainland. The disease, known as kauri dieback or kauri collar rot, is believed to be over 300 years old and causes yellowing leaves, thinning canopy, dead branches, lesions that bleed resin, and tree death.
Phytophthora agathidicida was identified as a new species in April 2008. Its closest known relative is Phytophthora katsurae. The pathogen is believed to be spread on people's shoes or by mammals, particularly feral pigs. A collaborative response team has been formed to work on the disease. The team includes MAF Biosecurity, the Conservation Department, Auckland and Northland regional councils, Waikato Regional Council, and Bay of Plenty Regional Council. The team is charged with assessing the risk, determining methods and their feasibility to limit the spread, collecting more information (e.g. how widespread), and ensuring a coordinated response. The Department of Conservation has issued guidelines to prevent the spread of the disease, including keeping to defined tracks, cleaning footwear before and after entering kauri forest areas, and staying away from kauri roots.


Agave americana, common names century plant, maguey, or American aloe, is a species of flowering plant in the family Asparagaceae, native to Mexico and the United States in Texas. It is cultivated worldwide as an ornamental plant, and has been naturalized in many regions, including parts of the West Indies, South America, Mediterranean Basin, Africa, Canary Islands,  India, China, Thailand, and Australia.
Despite the common name "American aloe", it is not in the same family as aloe, though it is in the same order, Asparagales.


Although it is called the century plant, it typically lives only 10 to 30 years. It has a spread around 1.8–3.0 m (6–10 ft) with gray-green leaves of 0.9–1.5 m (3–5 ft) long, each with a prickly margin and a heavy spike at the tip that can pierce deeply. Near the end of its life, the plant sends up a tall, branched stalk, laden with yellow blossoms, that may reach a total height up to 8–9 m (25–30 ft).
Its common name derives from its semelparous nature of flowering only once at the end of its long life. The plant dies after flowering, but produces adventitious shoots from the base, which continue its growth.


A. americana is cultivated as an ornamental plant for the large dramatic form of mature plants—for modernist, drought-tolerant, and desert-style cactus gardens—among many planted settings. It is often used in hot climates and where drought conditions occur.  The plants can be evocative of 18th-19th-century Spanish colonial and Mexican provincial areas in the Southwestern United States, California, and xeric Mexico. It is also a popular landscape plant in dry beach gardens in Florida and coastal areas of the Southeastern United States.
When grown as a house plant, A. americana is tolerant of light levels ranging from direct sunlight to shade and requires little watering. It does require a winter resting period at temperatures around 10 to 12 °C (50 to 54 °F). It should be grown in a very porous, sandy potting soil, allowed to dry out between waterings, and repotted every spring.


Two subspecies and two varieties of A. americana are recognized by the World Checklist of Selected Plant Families:
A. americana subsp. americana
A. americana subsp. protamericana Gentry
A. americana var. expansa (Jacobi) Gentry
A. americana var. oaxacensis Gentry
A. americana var. marginata Trel. in L.H.Bailey, Stand. Cycl. Hort. 1: 235 (1914).
A. americana var. picta (Salm-Dyck) A.Terracc., Prim. Contr. Monogr. Agave (1885).
Cultivars include:
'Marginata' agm with yellow stripes along the margins of each leaf
'Mediopicta' agm with a broad cream central stripe
'Mediopicta Alba' agm with a central white band
'Mediopicta Aurea' with a central yellow band
'Striata' with multiple yellow to white stripes along the leaves
'Variegata' agm with white edges on the leaves.
(those marked agm, as well as the parent species, have gained the Royal Horticultural Society's Award of Garden Merit).


Agave americana contains agavose, a sugar with the same chemical formula of sucrose (C₁₂H₂₂O₁₁), but with only 0.32 of its sweetening power, as well as agavasaponins and agavosides. It is used in traditional medicine to treat several ailments, and as a laxative, diuretic and diaphoretic, although a systematic review did not find enough data to support its effectiveness or safety. A. americana is known to be able to cause severe allergic dermatitis.


The Aztecs pulped the leaves of A. americana to create paper—the Humboldt fragments were made in this way.


Agave deserti (desert agave, mescal, century plant or maguey) is an agave native to desert regions in southern California, Arizona, and Baja California. Its tall yellow flower stalks dot dry rocky slopes and washes throughout the spring.
It forms a rosette of fleshy gray-green leaves 20–70 cm long and 4.5–10 cm broad, with sharp spines along the edges and at the tips. It flowers at maturity (20 to 40 years), sending up an inflorescence 2–6 m tall. The panicle bears numerous yellow, funnel-shaped flowers 3–6 cm long.
There are two varieties:
Agave deserti var. deserti. Plants usually with numerous rosettes; perianth tube 3–5 mm. Southern California only.
Agave deserti var. simplex (Gentry) W.C.Hodgson & Reveal. Plants usually with one or only a few rosettes; perianth tube 5–10 mm. Southern California and Arizona.


The desert agave is drought-tolerant but requires good drainage.
The desert dwelling Native Americans used fibers from the leaves to make cloth, bowstrings, and rope. Young flower stalks (roasted), buds, and hearts of plants (also roasted) were eaten. Natives of southern California commonly harvested the "heads" using a specialized digging stick and roasted the leaves and heart alike. Food thus obtained often became a dietary staple, even into drought years.
Alcoholic drinks were also manufactured from the sweet juices of this and other agaves.


Flora of North America: Agave deserti
C.Michael Hogan ed. 2010. “Agave deserti”. Encyclopedia of Life
Jepson Flora Project: Agave deserti
Dole, Jim W. and Rose, Betty B., Shrubs and Trees of the Southern California Deserts, 1996, Foot-Loose Press.


Agave lechuguilla (common name in Chihuahua: lechuguilla, meaning "small lettuce") is an Agave species found only in the Chihuahuan Desert. The plant flowers once in its life and then dies.


The plant reproduces most often through underground offshoots, creating large colonies. It also can flower at any time after the plant has reached three to 21 years of age, producing a leafless stalk that can reach 3.7 metres (12 feet) in height. The flower clusters are located at the top and are funnel-shaped in purples, reds, and yellows. The plant dies after flowering in May–July. The leaves are long, tough, and rigid, with very sharp, hard points that can easily penetrate clothing and even leather, giving the colloquial name "shin-daggers".


It is an indicator species in the Chihuahuan Desert, the only place it is found. It typically grows on calcareous soils.


The plant makes up a large part of the diet of the collared peccary (javelina) in some areas. Additionally, the flowers are a source of nutrients for insects, bats, and some birds. The plant is toxic to cattle and sheep, however.


The water stored in the flowering stalks of this plant, rich in salts and minerals, is sold in Mexico as a sport drink. Native Mexicans have used fibers from the leaves (commonly called ixtle). Roots of the plants were used as soap by Native Americans.


Agave parryi, known as Parry's agave or mescal agave, is a flowering plant in the family Asparagaceae, subfamily Agavoideae. It is a slow-growing succulent perennial native to Arizona, New Mexico, and northern Mexico.
The leaves are grey green and have a spine at the tip.  One of the distinguishing features is that the point on the tip, which is typically dark tan, brown, or black, is darker than the leaf.  Indentations of previous leaves show on the back of each leaf.  The Huachuca variety grows in a rosette pattern as large as 2½ feet in diameter.
Because of its compact size, plus its low water use and low maintenance, Huachuca agave is considered a good landscaping plant for desert residential landscaping.  It requires full sun.  It is hardy to roughly −5 °F (−21 °C), though there are reports of specimens surviving temperatures at −20 °F (−29 °C).
Parry's agave is evergreen.  Aged agave produce a twelve-foot stalk with bright yellow blooms.  They then die after blooming, as all leaf and root resources are put into the stalk, flowers, and seeds.  It can be propagated by either offset or seed.
This plant has gained the Royal Horticultural Society’s Award of Garden Merit.


Agave parryi var. huachucensis, Huachuca agave
Agave parryi var. truncata, Mescal agave
Agave parryi var. couseii


Agave salmiana (also known as maguey pulquero and  green maguey) is a species of the family Asparagaceae, native to central and southern Mexico. It is also reportedly naturalized in South Africa, Italy and Spain, specially in the Canary Islands.
This species, also called Agave of Salm or Salm-Dick, is dedicated to the German prince and botanist Joseph zu Salm-Reifferscheidt-Dyck (1773-1861).


A. salmiana  presents a spiral-shaped rosette with large flared and erect leaves. These leaves are thick, dark green with a large point at the tip and strong spines on the edges. When a leaf has unfolded, it leaves an imprint on the leaf underneath.
Like most agaves, the species is monocarpic, that is to say it only flowers once and then dies. This flowering occurs after 15 to 25 years producing a vertical floral stem, typically up to 4 m (13 ft) long and bearing greenish-yellow flowers.  The largest specimens have been significantly taller. One specimen growing at the Strawberry Canyon Botanical Garden on the campus of U. C. Berkeley, Berkeley, California in 1974 produced an inflorescence with a total height of 52 feet (16 m) of which the scape or peduncle was about 39' 4" (12 m) and the panicle per se was 13 feet (4 m). Hermann J.H. Jacobsen states that the inflorescence of A. salmiana has reached an overall height of 62 feet (19 m), making the inflorescence of A. salmiana the tallest of any known species of plant.
Old plants reach 1.8 m in height and the leaves form a rosette 3.6 m in diameter.
The variety A. salmiana var. ferox (K.Koch) Gentry is often encountered in cultivation. The epithet ferox is due to the hard and long (up to 8 cm) spines.


Originally from southern and central Mexico, it was introduced into gardens with a Mediterranean climate in Europe and sometimes escaped into the wild, thus becoming naturalised in some parts of southern Europe.


Cultivation is easy in a well-drained sandy soil with sunny exposure. For a pot culture, it requires a container of very large size to remain in an harmonious appearance. It can be used to stabilise a slope. It can withstand a light frost if it is completely dry. It is multiplied more easily by planting shoots than by seedlings.


Agave shawii is a species of monocarpic succulent plant in the genus Agave, commonly known as Shaw's agave. It is a rosette-forming plant characterized by glossy, green leaves with toothed margins. After several years of slow growth, the plant puts all of its resources to produce a towering stalk of flowers, and then dies. The death of the flowering rosette is compensated by the growth of numerous clonal pups. This species is segregated into two subspecies, one native to the coast of southwestern California and northwestern Baja California, known commonly as the coast agave, and another native to the Baja California Desert, known as the Goldman agave.
For centuries, this species proved to be an invaluable source of accessible and abundant food for the indigenous peoples in the region, like the Kumeyaay, Tiipai and Paipai. After the European colonization of the Americas, the Spanish missionaries discouraged use of the agave, and moved the native peoples inland. Further development of the agave's habitat by American settlers contributed to the dwindling population of the species. Only two small populations are left within the political boundaries of the United States, one with only a single individual. In Mexico, it is still abundant but threatened by coastal development. Subspecies shawii is designated as an endangered species by the California Native Plant Society and the IUCN. The plant is named for Henry Shaw, the founder of the Missouri Botanical Garden.


Agave shawii is a very slow-growing, small-to-medium-sized agave.
The foliage is arranged in a rosette that measures 8 centimetres (3.1 in) to 2 metres (6.6 ft) wide. There may be numerous rosettes on top of erect to decumbent trunks that emerge from the rootstock. The foliage is glossy, colored light to dark green, and positioned in an ascending fashion. The leaves are shaped narrow to ovate, measuring 20–50 cm (7.9–19.7 in) long by 8–20 cm (3.1–7.9 in) wide, with the abaxial (lower surface) surface convex. Leaves feel thick, fleshy, and rigid, and their margins are armed with colorful and well-defined spines. The spine at the tip of the leaf measures 2–4 cm (0.79–1.57 in).
The panicle-like inflorescence grows 2–4 m (6.6–13.1 ft) tall. The bracts (leaves on the inflorescence) are persistent, shaped lanceolate to triangular, and are 10–25 cm (3.9–9.8 in) large. Subtended by the bracts are 8–14 lateral umbels (branches), which are 10–20 cm (3.9–7.9 in) long. Each umbel consists of a mass of yellowish or reddish flowers, with 35–75 flowers per cluster. After flowering, it produces fruits 5.5–7 cm (2.2–2.8 in) large, containing fertilized (black-colored) and unfertilized (white-colored) seeds.
It generally flowers September to May, and as typical for agaves, the rosette dies thereafter. Although capable of reproducing by suckering, populations vary considerably in their behavior, with some consisting entirely of individual rosettes, while others form groups or colonies of clones.


The infraspecific taxa are variously labeled as varieties or subspecies, depending on the source.
Agave shawii subsp. shawii — The autonymous subspecies. The southernmost "typical" plants that can easily be distinguished occur near San Quintin. Near El Rosario, both subspecies become difficult to discern.
Agave shawii subsp. goldmaniana (Trel.) Gentry — Commonly known as the Goldman agave. The rosette leaves are 40–70 cm (16–28 in) long, and 10–18 cm (3.9–7.1 in) wide, shaped lanceolate. The inflorescence has 18–25 umbels on a 3–5 meter stem. The long and broader shape of the inflorescence, along with the narrow leaves set it apart from the typical subspecies. It predominates in the coast and desert of the southern part of Baja California state. This subspecies has much higher rates of seed set and seedling recruitment compared to subsp. shawii.
Agave sebastiana, a plant native to Cedros Island and the Vizcaino Peninsula, was formerly placed in this species as Agave shawii var. sebastiana.


This species is primarily distributed in, and near-endemic to, the state of Baja California in Mexico. It was formerly widespread along the coast of San Diego County, California, but coastal development has reduced the entire population to just two natural occurrences, of which only one is wholly natural. There is a 25 km (16 mi) north-to-south gap between the southernmost natural plants in San Diego County and the northernmost natural plants in Baja California. The coastal subspecies shawii is the taxon present in San Diego County, and ranges south to El Rosario in Baja California. At El Rosario, it is subsumed by the desert subspecies goldmaniana, which ranges from there to Santa Rosaliíta in southern Baja California.
Subspecies shawii only occurs in a vegetation community known as maritime succulent scrub, which is found along the Pacific Coast of northern Baja California state of Mexico and southwesternmost San Diego County of California. This habitat only extends a few kilometers into the United States, occurring in narrow bands on coastal bluffs with almost constant exposure to coastal winds with high salt content. Maritime succulent scrub is regarded as the most xeric of the coastal sage vegetation types, and is dominated by other succulent plants such as cacti (Bergerocactus, Cylindropuntia, Ferocactus, Mammilaria, Opuntia), cliff spurge (Euphorbia misera) and Crassulacean plants like Dudleya. Subspecies shawii was probably once found north of Torrey Pines, but with the development of all viable habitat, has all but disappeared from the American side of the border.
Subspecies goldmaniana grows in the southern portion of the maritime succulent scrub and in the Central Desert of southern Baja California.


Agave shawii is cultivated as an ornamental plant, by specialty plant nurseries. It is used in cactus and succulent gardens, containers, and for drought tolerant and wildlife gardens.
Plants enjoy a sandy loam soil that has good drainage. It is recommended to plant in a location where the sharp spines will not be a hazard. Virtually disease free except for scale insects. Roots are very rapid responders to rain and dry plants start growing feeder (rain) roots after exposure to the rain. Plants develop best color when exposed to full sun along the coast. Some relief from the hot afternoon sun in the inland valleys with partial shade would provide the best results for growers. Within the United States, it is not recommended to grow this plant in desert locations like Las Vegas, but it will thrive in coastal locations from San Diego to San Francisco.
In a preservation effort, Shaw's agaves were introduced into the Torrey Pines State Reserve and Cabrillo National Monument in San Diego, California and have established themselves. There is also large colony of Shaw's Agave in the San Diego Botanic Garden located in Encinitas, California. The San Elijo Lagoon Nature Center in Encinitas also has Shaw's agaves planted as part of their California native plant xeriscaping.


The coastal agave (Tiipai: me’ellh, ma’alh, ma’alh jas’ilh, Paipai: me’elh jas’ilh ruii kiyak) was widely utilized by indigenous peoples until the European colonization of the Americas forced natives away from the coastal region where Agave shawii occurs. Subsequently, the lack of interaction between native peoples and their agaves led to the decay of knowledge regarding the usage of the local agaves, with the cultivation of agaves in the entire Kumeyaay-Paipai cultural region now only occurring in the village of Santa Catarina.
The Spanish explorers and missionaries from Sebastián Vizcaíno and Junipero Serra's expeditions noticed the usage of the agave for fiber and food. Serra said on his arrival to the coast near El Descanso, "We saw the land was covered with very good mescal but I think the Indians pay little attention to it due to the abundance of fish and other foods." Serra's observations fail to take into account the seasonal changes in the food supply, as the agave was heavily utilized in other months. Juan Crespí stated that the related Agave deserti was "...a delicious, sweet preserve. This is the wretched heathens’ daily bread."
Agaves had high importance for indigenous food networks, but today the laborious effort of preparing the agaves is rarely undertaken. Preparation of the agave for consumption included locating suitable heads, using a digging stick to extract the heads, constructing an earth oven, where the agave head would be cooked for two days before it was ready to eat. Importance of the agave as a food is supported by archaeological records showing high dental attrition in the remains of indigenous peoples, likely due to the frequent consumption of tough plant fibers from the agave.
The fiber of the agave would have been put to a great variety of uses, for making belts, bowstrings, carrying nets, cordage, sandals, and other indispensable items. Vizcaíno noted that the cordage was used by fishermen to create lines of much higher quality than his own. Some Paipai women still produce agave fiber products today, which are sold as handicrafts, but also offer to teach both natives and non-natives throughout the region.


Agave utahensis is a species of agave known by the common name Utah agave.
Varieties of the species include the Nevada agave and Kaibab agave.
It is an uncommon plant of the United States' desert southwest, in the states of Utah, Nevada, Arizona, and California. Although plants in some areas are threatened, overall the species is stable and is considered to be of Least Concern by the IUCN.


Agave utahensis is a rosette-shaped agave having blue-green sharp-spiked leaves.
The raceme inflorescence is very tall, reaching a maximum of 4 m (12 ft). It is generally yellow or yellow-green with bulbous yellow flowers. The fruits are capsules 1 to 3 centimeters long and containing black seed.


Agave utahensis is cultivated as an ornamental plant. In the UK it has won the Royal Horticultural Society's Award of Garden Merit.
The plant was used for food and fiber by local Native American peoples such as the Havasupai. Among the Navajo, the plant is used to make blankets.


The grayish baywing (Agelaioides badius), formerly known as the bay-winged cowbird, is a species of bird in the family Icteridae. It is currently placed in the genus Agelaioides  but has traditionally been placed in the genus Molothrus. It is found in the northern half of Argentina, Bolivia, Uruguay, Paraguay and southern and central Brazil, The isolated population in north-eastern Brazil is usually now considered a separate species, the pale cowbird or pale baywing (Agelaioides fringillarius). The greyish baywing has been recorded as a vagrant in Chile.


It has a total length of approximately 18 cm (7 in). It is overall ashy-brown with contrasting black lores and rufous wings. The taxon fringillarius has more black in the face and is overall more rufescent (less ashy).
It is social and commonly seen in small groups. Unlike the "true" cowbirds in the genus Molothrus, this species is not a brood parasite. In contrast, the screaming cowbird is a brood parasite of the grayish baywing, and while adult screaming cowbirds are overall blackish, juvenile screaming cowbirds closely resemble grayish baywings.


The red-winged blackbird (Agelaius phoeniceus) is a passerine bird of the family Icteridae found in most of North America and much of Central America. It breeds from Alaska and Newfoundland south to Florida, the Gulf of Mexico, Mexico, and Guatemala, with isolated populations in western El Salvador, northwestern Honduras, and northwestern Costa Rica. It may winter as far north as Pennsylvania and British Columbia, but northern populations are generally migratory, moving south to Mexico and the southern United States. Claims have been made that it is the most abundant living land bird in North America, as bird-counting censuses of wintering red-winged blackbirds sometimes show that loose flocks can number in excess of a million birds per flock and the full number of breeding pairs across North and Central America may exceed 250 million in peak years. It also ranks among the best-studied wild bird species in the world. The red-winged blackbird is sexually dimorphic; the male is all black with a red shoulder and yellow wing bar, while the female is a nondescript dark brown. Seeds and insects make up the bulk of the red-winged blackbird's diet.


The red-winged blackbird is one of five species in the genus Agelaius and is included in the family Icteridae, which is made up of passerine birds found in North and South America. The red-winged blackbird was formally described as Oriolus phoeniceus by Carl Linnaeus in 1766 in the twelfth edition of his Systema Naturae, but was later moved with the other American blackbirds to the genus Agelaius by Louis Jean Pierre Vieillot in 1816. Linnaeus specified the type location as "America" but this was restricted to Charleston, South Carolina in 1928. The genus name is derived from Ancient Greek agelaios, meaning "gregarious". The specific epithet, phoeniceus, is Latin meaning "crimson" or "red". The red-winged blackbird is a sister species to the red-shouldered blackbird (Agelaius assimilis) that is endemic to Cuba. These two species are together sister to the tricolored blackbird (Agelaius tricolor) that is found on the Pacific coast region of the California and upper Baja California in Mexico.
Depending on the authority, between 20 and 24 subspecies are recognised which are mostly quite similar in appearance. However, there are two isolated populations of bicolored blackbirds that are quite distinctive: A. p. californicus of California and A. p. gubernator of central Mexico. The taxonomy and relationships between these two populations and with red-winged blackbirds is still unclear. Despite the similarities in most forms of the red-winged blackbird, in the subspecies of Mexican Plateau, A. p. gubernator, the female's veining is greatly reduced and restricted to the throat; the rest of the plumage is very dark brown, and also in a different family from the European redwing and the Old World common blackbird, which are thrushes (Turdidae). In the California subspecies, A. p. californicus and A. p. mailliardorum, the veining of the female specimens also covers a smaller surface and the plumage is dark brown, although not in the gubernator grade; and also its superciliary list is absent or poorly developed. The male subspecies mailliardorum, californicus, aciculatus, neutralis, and gubernator lack the yellow band on the wing that is present in most male members of the other subspecies. The red-shouldered blackbird was formerly considered as a subspecies of red-winged blackbird. They were split by the American Ornithologists' Union in 1997.
Listed below are the red-winged blackbird subspecies and groups of subspecies recognized as of January 2014 with their respective distribution areas and the location of their wintering quarters:
Group phoeniceus:
A. p. arctolegus – from southeastern Alaska and Yukon to the north-central United States; migrates to the south-central United States.
A. p. fortis – from Montana to southeastern New Mexico (east of the Rocky Mountains); migrates to Texas.
A. p. nevadensis – from southeastern British Columbia to Idaho, southeastern California, and southern Nevada; migrates to southern Arizona.
A. p. caurinus – from the southwest coast of British Columbia to northwest California; migrates to central California.
A. p. aciculatus – mountains of central-southern California (central-eastern Kern County).
A. p. neutralis – from the coast of southern California (San Luis Obispo County) to the northwest of Baja California.
A. p. sonoriensis – from southeastern California to northeast Baja California, southern Nevada, central Arizona, and northwest Mexico.
A. p. nyaritensis – coastal plains of southwestern Mexico (Nayarit).
A. p. grinnelli – Pacific Slope from western Guatemala to northwest Costa Rica (Guanacaste).
A. p. phoeniceus – from southeastern Canada to Texas and the southeastern United States.
A. p. littoralis – Gulf Coast from Southeast Texas to Northwest Florida.
A. p. mearnsi – extreme southeast Georgia and northern Florida.
A. p. floridanus – South Florida (Everglades to Key West).
A. p. megapotamus – from central Texas and the lower Rio Bravo valley to eastern Mexico (northern Veracruz).
A. p. richmondi – Caribbean slope from Mexico (southern Veracruz) to Belize and northern Guatemala.
A. p. pallidulus – southeast Mexico (north of the Yucatan peninsula).
A. p. nelsoni – south-central Mexico (from Morelos and the adjacent Guerrero west of Puebla and Chiapas).
A. p. matudae – tropical southeast Mexico (not always recognised).
A. p. arthuralleni – northern Guatemala.
A. p. brevirostris – Caribbean slope of Honduras and southeastern Nicaragua (sometimes included in richmondi).
A. p. bryanti – northwest Bahamas.
Group californicus/ mailliardorum:
A. p. mailliardorum – Central California Coast.
A. p. californicus – Central Valley of California.
Group gubernator :
A. p. gubernator – Mexican Plateau (Durango to Zacatecas, Mexico and Tlaxcala).


The common name for the red-winged blackbird is taken from the mainly black adult male's distinctive red shoulder patches, or epaulets, which are visible when the bird is flying or displaying. At rest, the male also shows a pale yellow wingbar. The spots of males less than one year old, generally subordinate, are smaller and more orange than those of adults. The female is blackish-brown and paler below. The female is smaller than the male, at 17–18 cm (6.7–7.1 in) long and weighing 41.5 g (1.46 oz), against his length of 22–24 cm (8.7–9.4 in) and weight of 64 g (2.3 oz). The smallest females may weigh as little as 29 g (1.0 oz) whereas the largest males can weigh up to 82 g (2.9 oz). Each wing can range from 8.1–14.4 cm (3.2–5.7 in), the tail measures 6.1–10.9 cm (2.4–4.3 in), the culmen measures 1.3–3.2 cm (0.51–1.26 in) and the tarsus measures 2.1 cm (0.83 in). The upper parts of the female are brown, while the lower parts are covered by an intense white and dark veining; also presents a whitish superciliary list. Females exhibit a year or salmon pink stain on the shoulders and a clear pink color on the face and below this, while older show a stain usually more crimson on the shoulders and dark pink hue on and under the face. Observations in females in captivity indicate that small amounts of yellow pigment are present on the shoulders of these after leaving the nest, that the concentration of the pigment increases with the first winter plumage after the change of the feathers and that the passage from yellow to orange generally takes place in the second summer with the acquisition of the second winter plumage, after which no further changes in feather color occur. The colored area on the wing increases in surface with the age of the female, and varies in intensity from brown to a bright red-orange similar to that of the males in their first year.
Young birds resemble the female, but are paler below and have buff feather fringes. Both sexes have a sharply pointed bill. The tail is of medium length and is rounded. The eyes, bill, and feet are all black. Unlike most North American passerines which develop their adult plumage in their first year of life so that the one-year-old and the oldest individual are indistinguishable in the breeding season, the red-winged blackbird does not. It acquires its adult plumage only after the breeding season of the year following its birth when it is between thirteen and fifteen months of age. Young males go through a transition stage in which the wing spots have an orange coloration before acquiring the most intense tone typical of adults.
The male measures between 22 and 24 cm (8.7 and 9.4 in) in length, while the female measures 17 or 18 cm (6.7 or 7.1 in). Its wingspan is between 31 and 40 cm (12 and 16 in) approximately. Both the peak male and the legs, the claws and the eyes are black; in the female beak is dark brown and clear in the upper half at the bottom, and the tail is medium in length and rounded. As in other species polygyny exists, the red-winged blackbird exhibit considerable sexual dimorphism both in plumage and size, males weighing between 65 and 80g the females about 35g. Males are 50% heavier than females, 20% larger in its linear dimensions, and 20% larger compared to the length of their wings. The trend towards greater dimorphism in the size of non-monogamous ichterid species indicates that the larger size of males has evolved due to sexual selection.
The male is unmistakable except in the far west of the US, where the tricolored blackbird occurs. Males of that species have a darker red epaulet edged with white, not yellow. Females of tricolored, bicolored, red-shouldered and red-winged blackbirds can be difficult to identify in areas where more than one form occurs. In flight, when the field marks are not easily seen, the red-winged blackbird can be distinguished from less closely related icterids such as common grackle and brown-headed cowbird by its different silhouette and undulating flight.


Two keto-carotenoids – carotenoid with a ketone group – reds synthesized by the birds themselves – namely astaxanthin and canthaxanthin – are responsible for the bright red color of the wing spots, but two yellow dietary precursor pigments – lutein and zeaxanthin – are also present in moderately high concentrations in red feathers. Astaxanthin is the carotenoid more abundant (35% of the total), followed by lutein (28%), canthaxanthin (23%) and zeaxanthin (12%). Such a balanced combination of dietary precursors and metabolic derivatives in colored feathers is quite unusual, not only within a species as a whole but also in individuals and particular feathers.
After removing the carotenoids in an experiment, the red feathers acquired a deep brown coloration. This is because the feather barbles of the colored spot contain melanin pigments – mainly eumelanin, which was equivalent to 83% of all melanins, but also pheomelanin at a concentration approximately equal to that of carotenoids, which seems to be a rare trait for carotenoid-based ornamental plumage. On the other hand, the feathers of the yellow stripes of the males are devoid of carotenoids —except occasionally when they appear tinged with a pink coloration derived from small amounts of said pigments— and present high concentrations of pheomelanin —82% of all melanins. Melanin concentrations in the yellow band are even higher than in the red spot.


These markings are vital in the defense of the territory. Males with larger spots are more effective at chasing away their non-territorial rivals and are more successful in contests within aviaries. When the red shoulder patches were dyed black as part of an experiment, 64% of males lost their territories, while only 8% of control subjects did. However, males whose wings had been dyed before they had mated could still attract females and successfully reproduce. In the red-winged blackbird, the spots on the wings are a sign of threat among males and have an unimportant role, if any, in intersex encounters. Therefore, the spots are likely to have evolved in response to pressures linked to intrasexual selection. Additionally, neither the size nor the coloration of the same are linked to the reproductive success of the males with those females that are not their mates, that is, those with which they eventually mate. It has been suggested that also in the case of females, the best explanation for the evolution of a variable coloration in the shoulder spots is that their intensity indicates their physical condition in aggressive encounters between them.
The fact that female red-winged blackbirds do not appear to consistently use variability in the size and color of male wing spots when choosing a mate runs counter to the classic role of carotenoid pigmentation ornamental feathers, mostly used in the attraction of a couple. In turn, its use as a sign of aggressiveness and social status against rival males is not a common trait in carotenoid ornaments. On the other hand, ornaments with a preponderance of melanin do tend to have an important role as an indicator of status in avian populations, so the spots of red-winged blackbirds seem to work more as melanin ornaments than as carotenoids.


The calls of the red-winged blackbird are a throaty check and a high slurred whistle, terrr-eeee. The male's song, accompanied by a display of his red shoulder patches, is a scratchy oak-a-lee, except that in many western birds, including bicolored blackbirds, it is ooPREEEEEom. The female also sings, typically a scolding chatter chit chit chit chit chit chit cheer teer teer teerr.


The most critical period of feather molting runs from late August to early September. When viewed in flight, they have a misaligned or "moth-eaten" appearance and generally slower and more laborious travel. Their mobility is reduced due to the lack of several remiges or rectrices or these are not entirely renewed. Most of the red-winged blackbirds have moved almost entirely by October. By then, some birds have not completed the molt of the feathers of the capital region and the helmsmen of the center of the tail and the internal secondary sprouts have only partially emerged from the pod. Virtually all individuals have completed their molts by mid-October.
Birds do not begin their migration to wintering quarters until the two outer primary sprouts and the two inner or central rectrices have completed at least two-thirds of their development. Therefore, there is a correlation between molting, particularly replacement of the remiges and rectrices, and fall migration in red-winged blackbirds.


Juvenile plumage: in both males and females, juvenile plumage is similar in color and pattern to that of the adult female, except for the yellow coloration of the lower body and the sides of the head . The shoulder spots appear mottled and are brown and yellow or brown and beige. Other sources describe the juvenile plumage of the male as follows: above, including the sides of the head, the wings, the tail and the lesser coverts – the feathers of the "shoulders" -, dull brownish black – not seen no red at this stage—, with beige-bordered feathers, paler and narrower in primaries, rectrices, head, and bladderand deeper in the scapulars and secondaries; below, pinkish beige, ocher above chin, densely veined — except chin — with brownish black stripes; undefined ocher-beige superciliary list. The female is described as more brown above with less beige below and a closely veined chin.
First pre-basic molt (or post-juvenile molt): Generally begins 45–60 days after individuals have left the nest. The molt begins in August and the time at which it begins varies between early and late clutches. This is a complete molt, except for the retention in some individuals of a few down feathers under the wing.
Appearance in autumn and winter of the first basic plumage (also called the first winter plumage or immature plumage): in the male, it is black, with the feathers of the upper part bordered with brown or beige and those of the lower part bordered with beige or white. The bird then has a mottled appearance. The shoulder spot is generally orange with black speckles, especially on the yellow stripe. Some immature males have a reddish patch like adults, but with black specks on the yellow band. Others have a blackish spot on the shoulder. Other sources describe the male's first winter plumage as follows: all plumage, including wings and tail, greenish-black, much of it with beige and rust edges, paler underneath and faint or absent in primaries and rectrices; minor wing covers – "shoulders" – orpiment-dull orange, each feather with black subterminal bars or spots; medium beige, deep ocher coverts, generally mottled with black in subterminal areas, mainly in the beards of the inner part of the feathers; generally black spines.
Females are dark above with feathers bordered with beige or rust. The lower part shows black and white streaks, but with more beige on the chest and sometimes on the flanks than in the reproductive plumage. The medium and secondary major cover feathers are noticeably bordered with beige. They generally lack the pink coloration on the chin and throat – which may be beige, yellow, or light salmon – and the crimson wing patch – which may be rust, orange, or gray – typical of second winter plumage.
Appearance in spring and summer of the first basic plumage (also known as the first breeding plumage or sub-adult plumage): the males, which normally are not yet defending a territory, present a dull black coloration acquired by the wear of the edges of the feathers. The stain alar may be more noticeable than in the first winter plumage due to wear subterminal blacklists, which generally only remain in the form of small black spots. Mottled wing spots are characteristic of young individuals and the extent of orange is highly variable. Females, which are usually already breeding, exhibit plumage similar to the first winter plumage, but darker above due to wear on beige edges or rust on feathers. The chest is less beige, and has a black and white veining.
Second and subsequent prebasic molts (or postnuptial molts) : the second prebasic molt takes place approximately one year after the first. Postnuptial molts constitute complete molts, except for the occasional retention of a few down feathers under the wing.
Appearance in autumn and winter of the second and subsequent basic plumages (also called adult winter plumage or second winter plumage) : the male no longer exhibits the mottled appearance characteristic of the autumn and winter appearance of the first basic plumage. The lower part is almost immaculate and similar to that of the reproductive plumage. The head and back feathers and the secondary covers are bordered with brown and beige. The wing blot becomes bright scarlet-vermilion, while deep ocher beige coloration appears on the medium coats. Other sources describe the adult winter plumage of the male as follows: glossy greenish black; feathers of the head, back, major wing covers and tertiary more or less bordered, depending on the individual, beige and rust; below, paler or absent edges. The female's plumage is similar to the autumn and winter appearance of the first basic plumage, except that the wing spot is generally crimson and the chin and throat pink.
Aspect in summer and spring of the second and subsequent basic plumages (or adult bridal plumage): it is acquired through the wear of the feathers. is similar to the appearance in the spring and summer of the first basic plumage, but the alar spots of both sexes have a more intense color and chin and throat of the female. The beige and brown edges of the male feathers disappear.
Despite the fact that the brown or white tips on the feathers of the males are larger just after the molt and that they wear out throughout the year, the individuals vary considerably regarding the size of these non-black tips on the feathers in spring.


Complete replacement of wing feathers takes about eight weeks. However, birds in their first year frequently retain some of the under-wing coverts and juvenile tertiary remiges after post-juvenile moulting. Of seventy immature males examined during the last week of October, it retained 70% of older lower primary blankets. In most cases where partial replacement of the covert feathers occurs, it is the proximal coverts that the bird retains.


In some birds, the first signs of molt in the ventral feathers appear during the last days of July, when the feathers of the anterior portion of the laterals begin to fall. From there, the molt progresses backward along the sides and forward toward the throat and chin. The last ventral feathers to be replaced are those towards the center of the abdomen. The molt of the dorsal feathers begins around the first week of August. It begins at the bladder, progresses to the upper back, and then to the cervical region.
The earliest evidence of molting in the humeral plumes corresponds to the last days of July. The molt comes from the anterior region backwards. The change of the femoral feathers begins later than that of the humeral ones. However, the progression is similar. Replacement of feather feathers rarely begins before August 15. The progression is generally from the proximal end of the tibia to the tarsometatarsal region.


The red-winged blackbird is widely spread throughout North America, except in the arid desert, high mountain ranges, and arctic or dense afforestation regions. It breeds from central-eastern Alaska and Yukon in the northwest, and Newfoundland in the northeast, to northern Costa Rica in the south, and from the Atlantic to the Pacific. Northern populations migrate to the southern United States, but those that breed there, in Mexico, and in Central America are sedentary. Red-winged blackbirds in the northern reaches of the range are migratory, spending winters in the southern United States and Central America. Migration begins in September or October, but occasionally as early as August. In western and Central America, populations are generally non-migratory.
The red-winged blackbird inhabits open grassy areas. It generally prefers wetlands, and inhabits both freshwater and saltwater marshes, particularly if cattail is present. It is also found in dry upland areas, where it inhabits meadows, prairies, and old fields. In a large part of its distribution area, it constitutes the most abundant passerine bird in the swamps in which it nests. It is also present in areas without much water, where it inhabits open fields – often agricultural areas – and sparse deciduous forests.
In the winter of 1975–1976, near Milan (western Tennessee), red-winged blackbirds were observed resting in a mixed roost that came to house 11 million individuals in January and early February in a plantation of 4.5 hectares of yellow pine (Pinus taeda) with little undergrowth was seen in soybean fields during the day, being that these constituted only 21% of the habitat in the area and that the other bird species present in the roost were not commonly observed in these fields; they were also common in cornfields. the presences of the bird in feedlots has increased as winter progressed, but, accounting for less than 5% of the ichterids and starlings recorded in both feedlots of cows and pigs, they were much rarer there than the brown-headed cowbird, common grackle and common starling.


During the breeding season, the density of breeding adults is much higher in swamps than in highland fields. Although the highest concentrations of nesting red-winged blackbird are found in swamps, most of them nest in upland habitats since they are much more abundant. In a study conducted in the Wood County, Ohio between 1964 and 1968, the density of territorial males in wetland habitat was found to be 2.89 times those in upland habitat. But, because of the small amount of wetland habitat, the total estimated upland population of territorial males
was 2.14 times the wetland population. Alfalfa (Medicago sativa) and other legume crops (hay) were the principal habitat for breeding redwings in the county. Despite the marked preference for wetland habitats, the greater population in uplands reflects wetlands' scarcity.


In that same study, reproductive individuals in upland habitats demonstrated a slight preference for old and new grasses such as Phleum pratense, Dactylis glomerata, Poa spp., Festuca spp., and Bromus spp. In the early part of the breeding season and new non-graminoid herbaceous plants in the mid and late season. In wetlands, they consistently preferred old and new broadleaf monocotyledons, primarily Carex spp, broadleaf, and Typha spp, and consistently rejected old and new narrow-leaved monocots, primarily narrow-leaved Phalaris arundinacea and Calamagrostis canadensis, and non-graminoid herbaceous plants. Red-winged blackbirds breeding in the highlands favored older tall vegetation only in the early part of the breeding season on April to May, and higher new vegetation and dense vegetation throughout the breeding season. For their part, those who settled in wetlands seemed to have a slight predilection for taller old vegetation. During the breeding season, this species is attracted to tall vegetation that restricts visibility.
Early season preferences for old grassland in the highlands and old broadleaf monocotyledons in wetlands point to the importance of upright residual vegetation. Highland grasses and broadleaf monocots in wetlands stand partially vertically and are easily visible in early spring, unlike clovers, narrow-leaved monocotyledons in wetlands and most non-graminoid herbaceous plants. Old alfalfa plants are also partially upright in early spring, but they are not as consistently chosen a species as old grasses. The start of the territorial activity is earlier when the amount of residual vegetation is large. Vegetation structural strength also appears to be important for nesting as females tend to broadleaf monocotyledons in wetlands throughout the breeding season and new non-graminoid herbaceous plants in the mid to late season.
In southwestern Michigan, the density of cattail stems in different ponds was positively related to the concentration of reproductive adults. However, other studies detected a predilection for more scattered vegetation. One found that red-winged blackbirds avoided the marsh wren (Pantaneros chivirenes), a predator common in nests of this species, reproducing among more dispersed vegetation, which was more easily defended from the chivirines; conversely, the chivirines seemed to prefer the denser vegetation, where they were more likely to avoid the aggressiveness of the red-winged blackbird; These differences in habitat selection between one species and another resulted in spatial segregation of their breeding areas. On the other hand, red-winged blackbirds tend to opt for small lots of vegetation and plants with thick stems.


The red-winged blackbird is territorial, polygynous, gregarious and a short-distance migratory bird. Its way of flying is characteristic, with rapid wing flaps punctuated by brief periods of gliding flight. The behavior of males makes their presence easily perceived: they perch in high places such as trees, bushes, fences, telephone lines, etc. Females tend to stay low, prowling through the vegetation and building their nests. They can be found in home gardens, particularly during their migration, if seeds have been scattered on the ground. The forest curtains serve as a resting place during the day.
For several weeks after their first appearance in early spring, red-winged blackbirds are generally seen in flocks made up entirely of males. During those days, they are seldom seen at their breeding sites, except early morning and late afternoon. In most of the remaining hours of the day, they frequent open and often elevated agricultural land, where they feed mainly on grain stubble and grassy fields. When disturbed while eating, they fly to the nearest deciduous trees and immediately after landing they begin to sing.


The red-winged blackbird is omnivorous. It feeds primarily on plant materials, including seeds from weeds and waste grain such as corn and rice, but about a quarter of its diet consists of insects and other small animals, and considerably more so during breeding season. It prefers insects, such as dragonflies, damselflies, butterflies, moths, and flies, but also consumes snails, frogs, eggs, carrion, worms, spiders, mollusks. The red-winged blackbird forages for insects by picking them from plants, or by catching them in flight. Sometimes insects are obtained by exploring the bases of aquatic plants with their small beaks, opening holes to reach the insects hidden inside. Aquatic insects, particularly odonates emerging, are of great importance in the diet of red-winged blackbirds that breed in swamps. These birds typically capture the odonates when the larvae climb up the stem of a plant from the water, get rid of their exuviae, and cling to the vegetation while their exoskeletons harden. The years of emergence of Periodical cicadas, it provides an overabundant amount of food. In season, they also eat blueberries, blackberries and other fruits. According to Edward Howe Forbush, when they arrive north in the spring, they feed in the fields and meadows. Then, they follow the plows, collecting larvae, earthworms and caterpillars left exposed, and in case there is a plague of Paleacrita vernata caterpillars in a fruit orchard, these birds will fly a kilometer to get them for their chicks.
In season, it eats blueberries, blackberries, and other fruit. These birds can be lured to backyard bird feeders by bread and seed mixtures and suet. In late summer and in autumn, the red-winged blackbird will feed in open fields, mixed with grackles, cowbirds, and starlings in flocks which can number in the thousands. It feeds on corn while it is maturing; once the grain has hardened it is relatively safe from this bird, since its beak and digestive system are not adapted for the consumption of hard and whole corn grains, unlike the Common grackle, which has a longer and stronger beak. Studies of the stomachs of individuals of both sexes reveal that males consume higher proportions of crop grains, while females ingest a relatively larger amount of herb seeds and animal matter. In the winter of 1975–1976, near Milan, western Tennessee, corn and herb seeds were the main foods consumed by red-winged blackbird. Herbs whose seeds were commonly consumed were Sorghum halepense, Xanthium strumarium, Digitaria ischaemum, Sporobolus spp., Polygonum spp. and Amaranthus spp.


The red-winged blackbird nests in loose colonies. The nest is built in cattails, rushes, grasses, sedge, or alder or willow bushes. The nest is constructed entirely by the female over the course of three to six days. It is a basket of grasses, sedge, and mosses, lined with mud, and bound to surrounding grasses or branches. It is located 7.6 cm (3.0 in) to 4.3 m (14 ft) above water.
A clutch consists of three or four, rarely five, eggs. Eggs are oval, smooth and slightly glossy, and measure 24.8 mm × 17.55 mm (0.976 in × 0.691 in). They are pale bluish green, marked with brown, purple, and/or black, with most markings around the larger end of the egg. These are incubated by the female alone, and hatch in 11 to 12 days. Red-winged blackbirds are hatched blind and naked, but are ready to leave the nest 11 to 14 days after hatching.
Red-winged blackbirds are polygynous, with territorial males defending up to 10 females. However, females frequently copulate with males other than their social mate and often lay clutches of mixed paternity. Pairs raise two or three clutches per season, in a new nest for each clutch.
The reproductive season of the red-winged blackbird extends approximately from the end of April to the end of July. On the other hand, in different states has been estimated that the period in which the active nests contained eggs lay between beginning in late April and early late August; and in northern Louisiana nests were found to harbor chicks from late April to late July. The peak of the nesting season (the time with the highest number of active nests) has been recorded between the first half of May and the beginning of June in different places. A study in eastern Ontario found that although red-winged blackbirds began nesting earlier in years with warm springs, associated with low winter values in the North Atlantic Oscillation Index, egg laying dates remained unchanged. Male testosterone levels peak in the early part of the breeding season, but remain high throughout the season. Females reproduce for up to ten years.
Many aspects of territorialism (for example, the number of male songs and displays, and the number of intrusions into foreign territories) peak before mating. After this, the frequency of many of the territorial behaviors decreases and the males are mainly concerned with defending the females, eggs, and chicks against predation. Experiments in the systematic removal of birds from their territories suggest that the extra population of males that is present in swamps before copulations disappears after copulation.
Predation of eggs and nestlings is quite common. Nest predators include snakes, mink, raccoons, and other birds, even as small as marsh wrens. The red-winged blackbird is occasionally a victim of brood parasites, particularly brown-headed cowbirds. Since nest predation is common, several adaptations have evolved in this species. Group nesting is one such trait which reduces the risk of individual predation by increasing the number of alert parents. Nesting over water reduces the likelihood of predation, as do alarm calls. Nests, in particular, offer a strategic advantage over predators in that they are often well concealed in thick, waterside reeds and positioned at a height of one to two meters. Males often act as sentinels, employing a variety of calls to denote the kind and severity of danger. Mobbing, especially by males, is also used to scare off unwanted predators, although mobbing often targets large animals and man-made devices by mistake. The brownish coloration of the female may also serve as an anti-predator trait in that it may provide camouflage for her and her nest while she is incubating.


Predators of red-winged blackbirds include such species as raccoons, American mink, long-tailed weasels, Eurasian magpies, common grackles, owls, red-tailed hawks, short-tailed hawks, and snakes (such as the northern water snake and the plains garter snake). Ravens and grazers such as marsh wrens feed on eggs (and even small chicks), if the nest is left unattended, destroying the eggs, occasionally drinking from them, and pecking the nestlings to death.
The relative importance of different nest predators varies by geographic region: the top predators in different regions include the marsh wren in British Columbia, the magpies in Washington, and the raccoons in Ontario. The incidence of avian predation in red-winged blackbird nests is higher in western populations than in eastern populations.
Due to high predation rates, especially of eggs and chicks, the red-winged blackbird has developed various adaptations to protect its nests. One of them consists of nesting in groups, which reduces the danger since there is a greater number of alert parents. Nesting over water also lowers the chances of an attack. Nests in particular offer a strategic advantage as they are often hidden among dense riparian reeds, at a height of one or two meters. males often act as sentinels, using a repertoire of calls. Males in particular hunt down potential predators to scare them away, even when dealing with much larger animals. Aggressiveness of the red-winged blackbird towards the marsh wren, which also nests in swamps, causes a partial interspecies territorialism. On the other hand, nocturnal predators such as raccoons and American mink are not attacked by adults. Coloration of the female could serve to camouflage it, protecting it and its nest when it is incubated.
The red-winged blackbird can accommodate ectoparasites such as various Phthiraptera, the Ischnocera Philopterus agelaii and Brueelia ornatissima, and hematophagous mites, like Ornithonyssus sylviarum, and endoparasites like Haemoproteus quiscalus, Leucocytozoon icteris, Plasmodium vaughani, nematodes, flukes and tapeworms.


The red-winged blackbird aggressively defends its territory from other animals, and will attack much larger birds. During breeding season, males will swoop at humans who encroach upon their nesting territory. Male red-winged blackbirds also exhibit important territorial behaviors, most of which provides them with the necessary fidelity for many years to come. A few important factors for male red-winged blackbirds’ adherence to territories include food, hiding spaces from predators, types of neighbors, and reactions towards predators. Additionally, a study was done on site fidelity and movement patterns by Les D. Beletsky and Gordon H. Orians in 1987 which explained much of the males’ territorial behaviors once migrated and settled onto a territory of their own. Sufficient evidence had shown that males are committed to staying in their territory over a long period of time and are not more likely to change territories at a younger age due to limited experience of knowledge for success. Studies also showed that most of the males that were first-time movers to a new territory were between two and three years old. The majority of males that moved were young and inexperienced. Later on they had moved towards more available territories. If males had chosen to leave their territory for reproductive success, as an example, they would do so within a short distance. Males who moved shorter distances were more successful in reproducing than those who moved longer distances. Further studies showed that when males moved further away from their territories there was a decrease in probability of successfully fledging.
The maximum longevity of the red-winged blackbird in the wild is 15.8 years.


Red-winged blackbirds that breed in the northern part of their range, i.e., Canada and border states in the United States, migrate south for the winter. However, populations near the Pacific and Gulf coasts of North America and those of Middle America are year-round resident. Red-winged blackbirds live in both Northern U.S. and Canada, ranging from Yucatan Peninsula in the south to the southern part of Alaska. These extensions account for the majority of the continent stretching from California's Pacific coast and Canada to the eastern seaboard. Much of the populations within Middle America are non-migratory. During the fall, populations begin migrating towards Southern U.S. Movement of red-winged blackbirds can begin as early as August through October. Spring migration begins anywhere between mid-February to mid-May. Numerous birds from northern parts of the U.S., particularly the Great lakes, migrate nearly 1,200 km (750 mi) between their breeding season and winter Winter territorial areas differ based on geographic location. Other populations that migrate year-round include those located in Middle America or in the western U.S. and Gulf Coast. Females typically migrate longer distances than males. These female populations located near the Great Lakes migrate nearly 230 km (140 mi) farther. Yearly-traveled females also migrate further than adult males, while also moving roughly the same distance as other adult females. Red-winged blackbirds migrate primarily during daytime. In general, males’ migration flocks arrive prior to females in the spring and after females in the fall.


According to the American ornithologist Arthur Cleveland Bent, in the northern regions of its range the eastern red-winged blackbird is almost completely beneficial from an economic perspective and there are comparatively few complaints of severe crop damage. Their diet consists almost entirely of insects, very few of which are useful species, and herb seeds. However, it causes certain damages to the grains that germinate in spring and to sweet corn in summer, while the grains are still soft, tearing the foliaceous covering of the ears and ruining them from a commercial point of view. It also attacks other grains in a limited way, but most of what it consumes is waste left in the ground. In the Midwest, where these birds are much more abundant and where cereals are grown more extensively than in the North, red-winged blackbirds and other ichterids, in late summer and fall, do great damage to grain fields, both while they are maturing as when they are harvested . However, it has been claimed that even there are beneficial because the larvae harmful than removed from corncobs and plants beet and can counteract pests of caterpillars. In the southern states, they seriously harm rice by plucking seedlings in spring and eating the still-soft grains as they mature, being in this sense almost as harmful as the Bobolink. On the other hand, they are of some use in consuming the weed seeds that would otherwise devalue the product.
Being one of the most numerous birds on the continent, it plays an important role in the dispersal of other species. Since red-winged blackbirds gather and rest in such large numbers, the survival of certain species that join their flocks is likely to be affected by their company. They can also be an important source of food for animals such as raccoons and mink. Likewise, populations that nest and rest in swamps could cushion the effect of predation on duck species and other animals. In summary, these birds are so numerous and active that their mere presence and natural behavior is enough to influence the environment in a visible way.


Through the control of insect populations through predation and unwanted herbs with the consumption of their seeds, they allow the growth of larger plants and crops. They also eat on Anthonomus grandis and Hypera postica, two species of weevils affecting cotton and alfalfa respectively, as well as harmful caterpillars of the European gypsy moth (Lymantria dispar) and of the genus Malacosoma. In some areas of the southern United States, the seeds of the common plumber (Xanthium strumarium), a weed detrimental to soybeans and cotton, seems to be an important food source for the species.
During the breeding season, the approximately 8 million red-winged blackbirds nesting in Ohio and their chicks probably consume more than 5.4 million kilograms (12,000,000 lb) of insects, an average of almost 53 kg/km² (300 lb/sq mi). Many of these insects, such as the weevils (Hypera spp.), Come from alfalfa fields, pastures, oat fields and other crops. In cornfields, blackbirds often feed on corn worms (Helicoverpa zea) and beetles of the genus Diabrotica. In early spring, red-winged blackbirds consume corn borers (Ostrinia nubilalis) in fields with corn stubble. However, Bendell et al. (1981) found that the economic benefit of pest control, such as larvae of that lepidopteran, by the red-winged blackbird only compensated for 20% of the damage to crops caused by this bird.


The red-winged blackbirds can devastate farm fields. Despite the fact that they consume weed seeds, they are known to cause great damage to agriculture due to their habits of resting in massive groups and their taste for agricultural products. may be also causes harm to plantings corn, rice, sunflower and sorghum, particularly important near roosts. Red-winged blackbird is the largest species of Icterid in North America and the most damaging to crops. From 215 birds Neotropical migrants have been identified as causing, by a wide margin, the greatest economic loss. In North America, the damage to corn crops by this species has increased since the late 1960s to early 1980s, perhaps because of the increase in the area for grain production, and due to the reduction of small areas with stubble, hayfields and uncultivated land, which, in turn, accentuated the bird's dependence on corn to ensure its livelihood.
Apparently, the male does more damage to this grain than the female. In some areas of Ohio, corn can account for up to 75% of the diet of males and only 6% of that of females in August and September. In South Dakota, in the late summer, the Gizzards of the males studied contained 29% corn, while in the case of the female that number was limited to 9%.


The red-winged blackbird is the dominant species in the large concentrations of blackbirds that feed on the fields of sunflower, corn and small grains maturing in late summer or early fall in the Dakotas. In the 1970s, losses to sunflower and corn crops caused by blackbirds in the Dakotas exceeded $3 million annually for each case. In the northern part of the Great Plains, an area known as the Prairie Pothole Region, in red-winged blackbirds are very abundant in summer, they congregate in post-reproductive flocks that significantly harm crops, particularly sunflower plantations near their home sites. Most sunflower damage occurs between mid-August and early September, when the calorie content of immature seeds is low and birds must consume more of them to satiate themselves. During this initial stage of predation on sunflower crops in which more than 75% of the total damage is caused, the red-winged blackbird represent 80% of the blackbirds observed in the fields of this seed. This period predates the massive migration of birds and most of them are of local origin. Most remain within 200 km (120 mi) of their native sites until the molting of their feathers is complete or nearly complete in late August or early September. Damage can be quite serious in the center and southeast of North Dakota and Northeast South Dakota, areas of high concentration of sunflower production and abundant wetlands that attract red-winged blackbird during the breeding season.
Investigations conducted between 1968 and 1979 revealed that blackbirds, notably the black-winged blackbird and the Common grackle, annually destroyed less than 1% of corn crops in Ohio, amounting to a loss between 4 and 6 million dollars according to 1979 prices. Insects, weeds, diseases and fungi. They are likely to cause losses of more than 20% of the total potential maize harvest in the Midwest states, and harvesting procedures often leave 5% or more of the maize in the fields, revealing that comparative damage by Ichteridae in Ohio is not great. However, the average damage caused by these birds is not of as much economic importance as its distribution among producers. While 97.5% of cornfields studied in Ohio suffered a loss of less than 5%, which constituted about 60% of the total damage in the state, the remaining 2.5% often incurred losses of more than 5% and represented approximately 40% of total injury in Ohio.
All Ohio counties experience some degree of predation on their maize crops from blackbirds, but those most affected are a few counties where marshes that roost them still abound. The counties of Ottawa, Sandusky and Lucas, on the waters of Sandusky Bay and Lake Erie, were the hardest hit. These three counties, among the 19 studied between 1968 and 1976, contained 62% of the fields in which the losses exceeded 5% and 77% of those in which they exceeded 10%. Other counties with extensive localized damage were Erie, Ashtabula also located on the coasts of the mentioned water courses and Hamilton. Almost all the plantations with damages greater than 5% were within 8 km (5.0 mi) of some important roosting of blackbirds. In the 1968–1976 period, in northeast Sandusky County and northwest Ottawa, where large roosts of up to a million birds were discovered in late summer and fall, average losses exceeded 9% in fields 3 to 5 km (1.9 to 3.1 mi) from the roosts, but they were less than 5% at 8 km (5.0 mi) and less than 2% at 16 km (9.9 mi). In southwestern Ontario, in the summer of 1964, it was found that the greatest damage to the cornfields by red-winged blackbird also occurred near roosts in swamps.