Agelaius phoeniceus
red-winged blackbird

The range of red-winged blackbirds extends from southern Alaska at its northern most point, to the Yucatan peninsula in the south and covers the greater part of the continent reaching from the Pacific coast of California and Canada to the eastern seaboard. Winter ranges for red-winged blackbirds vary by geographic location. Northern populations migrate south to the southern United States and Central America beginning in September or October (or occasionally as early as August). Most western and middle American populations are non-migratory. (Kirschenbaum, 1996; Yasukawa and Searcy, 1995)

Red-winged blackbirds roost and breed in a variety of habitats, but tend to prefer wetlands. They have been known to live in fresh and saltwater marshes. On drier ground, red-winged blackbirds gravitate towards open fields (often in agricultural areas) and lightly wooded deciduous forests. In winter red-winged blackbirds are most often found in open fields and croplands. (Kirschenbaum, 1996; National Wildlife Federation, 1996; Yasukawa and Searcy, 1995)

Easily distinguished by their glossy black feathers and red and yellow epaulets at the shoulder, males are the more brightly colored of the two sexes. Females tend to be dusty or brownish in color with dark stripes on their undersides. Females resemble large sparrows and are often recognized by their off-white eyebrow markings. Both males and females have dark legs and claws. The beak of male red-winged blackbirds tends to be totally black, whereas the beak of female red-winged blackbirds is dark brown on top with lighter brown on the underside. Both males and females have sharply pointed beaks. (Cleary, 2002; Jennings, 2000; Kirschenbaum, 1996; National Wildlife Federation, 1996; Neff, 1997; Yasukawa and Searcy, 1995)

Both male and female adult red-winged blackbirds are approximately 22 cm long, weigh 41.6 to 70.5 g and have a wingspan of 30 to 37 cm. Young males and females resemble adult females in coloration. Males undergo a transitional stage in which red epaulets appear orange in color before reaching their adult coloration. Olson (1994) showed that the average basal metabolic rate for adults in his experiments was 656 cm cubed/oxygen per minute and that the rate for three-day-old birds was 296 cm cubed/oxygen per minute. (Jennings, 2000; Kirschenbaum, 1996; National Wildlife Federation, 1996; Olson, 1994; Olson, 2001; Yasukawa and Searcy, 1995)

In the wild, red-winged blackbirds live 2.14 years, on average. The olded recorded red-winged blackbird in the wild lived 15 years and 9 months. (Yasukawa and Searcy, 1995)

As migratory birds, red-winged blackbirds share many characteristics with related species. They are strong fliers that will often migrate in flocks of a thousand or more. Roosting is often communal, resulting in large, centralized populations. Red-winged blackbirds are largely diurnal, spending most of their day foraging. Males defend territories during the mating season. As the mating season progresses, both males and females will spend more time within their territory or the territory of their mate. Although fighting among red-winged blackbirds is not all that common, even among males, it is known to occur. Males chase females at top speed during breeding seasion. Because of their broad range and tendency to colonize large roosting areas, red-winged blackbirds are extremely common, and are easy to find in the mating season when singing and sexual displays make them more visible. (Georgia Museum of Natural History and Georgia Department of Natural Resorces, 2000; Kirschenbaum, 1996; National Wildlife Federation, 1996; Yasukawa and Searcy, 1995)

Home Range

Home range and territory size vary greatly among red-winged blackbirds given their broad geographic range and extensive use of varying habits. Males tend to control territories of approximately 2,000 square meters, but some territories in marshes may be as small as 153 m^2, and some territories in upland habitat may be as large as 29,235 m^2. Females will occupy the territory of a single male, along with many other females. Males will defend their territory against other male red-winged blackbirds and also against other species of bird, including tricolored blackbirds and yellow-headed blackbirds, usually yielding to larger bird species. Birds in Costa Rica defend territories that are two to four times the size of temperate birds to the north. (Yasukawa and Searcy, 1995)

Males learn songs from other males. Both males and females have a variety of calls, some of which are the same. Only the males produce flight calls, which signal their exit from the territory. Both males and females employ distress and alarm calls which differ with the nature of the threat. Specific calls seem to communicate the presence of specific predators, such as raccoons or American crows. Short contact calls are also quite common, especially between a territorial male and the females in his territory. Threat calls are used to ward off predators, other birds and other red-winged blackbirds. Courtship calls vary little between males and females and are used only in the breeding season. Male songs are used to announce territorial boundaries and to attract mates. Female songs occur in the early breeding season and are most common before the incubation period.

Male red-winged blackbirds utter their familiar territorial and mate attraction song of "oak-a-lee" or "konkeree" in the spring. The last syllable is given more emphasis as a scratchy or buzzy trill. The common call used by both males and females is a "check" call. Males may utter a whistled "cheer" or "peet" call if alarmed. Other calls made by the male include a "seet," a "chuck," or a "cut." Females may utter a short chatter or sharp scream. A pre-mating call, "ti-ti-ti," may be uttered by both sexes. (Yasukawa and Searcy, 1995)

Visual displays are also a key form of communication, especial before and during mating. Males often use visual displays in order to attract females to their territories and to defend their territories and mates. An example is the "song spread" display. Males fluff their plumage, raise their shoulders, and spread their tail as they sing. As the display becomes more intense, the wings are more arched with the shoulders showing more prominently. Females will also engage in a "song spread" display directed at each other early in the breeding season. One possibility is that a female will defend a sub-territory within the male's territory. Females will engage in a "wing flip" display when a disturbance prevents them from returning to the nest. (Yasukawa and Searcy, 1995)

Red-winged blackbirds tend to be generalized feeders, consuming a greater amount of plant tissue in the non-breeding season and a greater amount of animal material in the breeding season. Red-winged blackbirds will feed on almost any plant material they can consume, preferring seeds and agricultural products, such as corn and rice. Adult red-winged blackbirds will consume a wide variety of foods including snails, frogs, fledgling birds, eggs, carrion, worms and a wide array of arthropods. Insects, especially Odonata (dragonflies and damselflies), Lepidoptera (butterflies and moths), and Diptera (true flies) are preferred, although arachnids and other insect and non-insect arthropods are consumed. For the most part, red-winged blackbirds feed on whatever they can find, picking insects out of plants and feeding on seeds and plant material. At times, red-winged blackbirds will hunt using their beaks for gaping (opening up of crevices in plant material with the beak). Red-winged blackbirds will also catch insects in flight. (Kirschenbaum, 1996; Yasukawa and Searcy, 1995)

As a result of high predation rates, especially of eggs and young, red-winged blackbirds have developed a number of anti-predator adaptations. 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).

Known predators include: racoons, American mink, black-billed magpies, marsh wrens, owls (family Strigidae) and hawks (order Falconiformes). (Georgia Museum of Natural History and Georgia Department of Natural Resorces, 2000; Jennings, 2000; National Wildlife Federation, 1996; Neff, 1997; Yasukawa and Searcy, 1995)

As highly generalized foragers and predators, red-winged blackbirds can have a great and lasting impact on their environment. By controlling insect populations through predation and weed populations through the consumption of seeds, red-winged blackbirds allow larger plants and crops to flourish. Paradoxically, red-winged blackbirds can also devastate plant growth and crop yields by feeding on the very plants their predation protects. As one of the most numerous species of birds on the continent, red-winged blackbirds also play key roles in the dispersal of other species. Because red-winged blackbirds tend to flock and roost in such large numbers the survival of other species of birds that encroach upon their territory must surely be affected by their presence. Large roosting habitats can also greatly affect the physical terrain. In short, red-winged blackbirds are so numerous and active that their presence and natural behavior alone is enough to impact an ecosystem in a very visible way. (Jennings, 2000; Kirschenbaum, 1996; National Wildlife Federation, 1996; Yasukawa and Searcy, 1995)

Despite their consumption of the seeds of unwanted weed pests, red-wing blackbirds have been known to cause great agricultural damage due to their colonial roosting habits and taste for agricultural products. Red-winged blackbirds often open the husks of developing corn stalks to feed on corn kernels. They are also known to feed on rice paddies and sunflower seeds. This consumption of ripening crops has lead many agriculturalists to employ extremely effective and often inhumane tactics in battling red-winged blackbird populations. These tactics include the frequent use of traps, poisons, and Avitol, a chemical agent that causes birds to behave in abnormal ways. Surfactants, or wetting agents, have also caused considerable damage to red-winged blackbirds. These detergents break down the waterproofing properties of the blackbird's feathers making them extremely vulnerable to low temperatures. Because of the long history of human-blackbird conflict and their continued threat to agricultural initiatives many of these techniques are used to this day. Less harmful methods of red-winged blackbird control include the use of noisemakers and the reduction of post-harvest crop waste, which attracts hungry red-winged blackbirds to farmland. (Yasukawa and Searcy, 1995)

Red-winged blackbirds have been known to feed on the seeds of numerous weeds that are detrimental to agricultural production. They also control insect populations, which can devastate agricultural yields. (Yasukawa and Searcy, 1995)

As one of the most common, widespread, and numerous birds in North America, little is done to protect red-winged blackbirds from the effects of habitat loss and urbanization. Because they can survive in a wide array of habitats, many populations can overcome losses of natural terrain. Nonetheless, red-winged blackbirds thrive in wetland areas and with the loss of natural wetlands it is likely that this species will suffer. This species is a migratory bird, and is protected under the U.S. Migratory Bird Treaty Act. (Jennings, 2000; Kirschenbaum, 1996; National Wildlife Federation, 1996; Yasukawa and Searcy, 1995)