[Species] | Red-winged blackbird
The red-winged blackbird (Agelaius phoeniceus) is a small to medium-sized new world blackbird that breeds from Alaska and Newfoundland to Florida and the Gulf of Mexico. Some isolated populations exist in El Salvador, Honduras and Costa Rica.
In terms of size red-winged blackbirds are virtually always inbetween 17 and 23 centimetres, have a wingspan of maximum 40 centimetres and weigh inbetween 32 and 77 grams. They’re highly sexually dimorphic, and with their glossy black plumage and the red-and-yellow shoulder badges, males are hard to mistake. Females on the other hand are streaked, dark brownish overall, paler on the breast and often with a whitish eyebrow.
Most of them breed in marshes, brushy swamps and hayfields. In addition to the aforementioned habitats they also forage in cultivated land and along the edges of water, and a variety of open habitats such as fields, mudflats, pastures and feedlots. As for most birds the habitats vary slightly in and outside of breeding season, but overall stay the same.
Although individuals mostly forage by simpling walking on the ground, picking up edible items by sight, they sometimes also do it in shrubs or trees. Outside of breeding season they sometimes forage in flocks that can include other new-world blackbirds or starlings.
Most of a red-winged blackbird’s diet consists of insects and seeds. During the summer they feed on more insects, spiders, millipedes and snails, and during the rest of the year, seeds of grasses and weeds as well as waste grain, berries, and small fruits are consumed. Most of the annual diet of an adult is herbivorous.
To defend their territory and attract a mate, males perch on a high stalk with feathers fluffed out and tail partly spread, singing at full volume. Males often have more than one mate. Both adults are very aggressive in nesting territory and attack larger birds that approach. Humans they usually don’t attack, but still loudly protest the presence of. The nest itself is placed in marsh growth like cattails or bulrushes, in bushes or saplings close to the water. It’s built by the female of grass, reeds, leaves, rootlets and lined with fine grass.
The female can lay up to 6 pale blue-green eggs with black, brown and purple markings. It is the only one to incubate the eggs, which takes a period of roughly 10 to 12 days. The young are fed by both parents, though the female usually does more. They are ready to leave the nest 11 to 14 days after hatching.
A study has revealed that populations and subspecies of red-winged blackbirds vary markedly in size and proportions. An experiment was conducted were nestlings were moved between populations. It found that they grew up to resemble their foster parents, indicating that instead of being genetically different, the differences are caused by the enviroment
Currently red-winged blackbirds are still among the most abudant birds of North America, but between 1966 and 2014 their populations have declined up to more than 30% according to the North American Breeding Bird Survey. Causes for that could be habitat loss, and of course the disapperance of many insects. The IUCN still evaluates them a species of least concern, with a total estimated breeding popualtion of 130 000 000.
Note: Wikipedia points out that the vocalisations of many western bicoloured blackbirds are ooPREEEEEom.
Photo credits: AL Solis, Micheal Oberman
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