Cowbirds are often symbolic of parasitism and negativity. Their bizarre nesting strategy poses a serious danger to large populations of songbirds. Cowbirds are considered by many to be villainous. Additionally, the cowbird can be seen as symbolic of vicious sibling rivalry.
Even though Brown-headed Cowbirds are native to North America, many people consider them a nuisance bird, since they destroy the eggs and young of smaller songbirds and have been implicated in the decline of several endangered species, including Kirtland’s Warbler and Black-capped Vireo.
Despite their harmless appearance though, they are a friend to no one. Cowbirds are selfish and greedy and they pave a path of destruction everywhere they go. Unfortunately, I’ve met some people who have similar habits. Cowbirds act the way they do thanks to thousands of years of survival of the fittest.
Mark E. Hauber, ornithologist and professor in integrative biology at the University of Illinois at Urbana-Champaign, brood parasitism is carried out by multiple species including birds, fishes and social insects such as termites, wasps, bees, ants and beetles. But cowbirds remain one of the best-known examples.
Cowbirds earned their common name from the habit of following herds of buffalo (and cattle) in search of the insect prey that were flushed up by the large grazing mammals. Plumage of the male brown-headed cowbird is mostly glossy black with a contrasting dark brown head, females are dull grayish brown.
Male Brown-headed Cowbirds have glossy black plumage and a rich brown head that often looks black in poor lighting or at distance. Female Brown-headed Cowbirds are plain brown birds, lightest on the head and underparts, with fine streaking on the belly and a dark eye.
Because cowbirds are native to the U.S., they are protected under the Migratory Bird Treaty Act and in most instances it is unlawful to use lethal control without a permit, including the removal of their eggs from a nest.
The adult cowbird may actually eat an egg or two of the host bird. Babies of the European cuckoo, also a notorious brood parasite, go a step further and kill the other babies when they hatch. But baby cowbirds usually do not kill their nest mates.
Brown-headed Cowbird
Brown-headed Cowbirds are smaller with a shorter tail than Common Grackles. Adult males have a brown head whereas Common Grackles have a blueish head.
Cowbirds: corral, herd.
It seems that cowbirds learn to recognize each other both through sound and sight, and by comparing the outside world to themselves. Juvenile Brown-headed Cowbirds and even nestlings respond to the sounds of their own species, especially the chatter call.
Cowbirds are songbirds, and members of the same taxonomic family as blackbirds and orioles, the Icteridae. Like their blackbird cousins they are sexually dimorphic. The males are larger than females; their bodies are black with a striking iridescent sheen, and their head is brown.
cowbird, any of five species of birds that belong to the family Icteridae (order Passeriformes) that are named for their habit of associating with cattle in order to prey upon insects stirred up from vegetation.
Cowbirds are birds belonging to the genus Molothrus in the family Icteridae. They are of New World origin, and are obligate brood parasites, laying their eggs in the nests of other species.
Male Brown-headed Cowbirds have glossy black plumage and a rich brown head that often looks black in poor lighting or at distance. Female Brown-headed Cowbirds are plain brown birds, lightest on the head and underparts, with fine streaking on the belly and a dark eye.
Cowbirds are constantly on the move, following herds of bison or cows to eat the insects cattle stir up from the ground. Since their food source is always roaming, the birds have no time to settle down and build a nest.
Cowbirds also feasted on insects that the bison’s hooves stirred up from the ground. These hordes of insects and birds followed bison herds, resulting in travelling ecosystems slowly crossing the prairie. Scientists often cite the relationship between brown-headed cowbirds and bison as a prime example of commensalism.
Because of the cowbirds dependency on the bison for food and the bison dependency on the cowbird as a pest removal service, they refer to these animals as having a mutualistic relationship, a symbiotic relationship that benefits both species.
Brown-headed cowbirds live throughout the United States, most of Canada, and Mexico. They are permanent residents in the southern parts of their range, while northern birds migrate to the southern United States and Mexico in winter.
Its spread has represented bad news for other songbirds: Cowbirds lay their eggs in nests of other birds. Heavy parasitism by cowbirds has pushed some species to the status of ’endangered’ and has probably hurt populations of some others.
BERKELEY – America’s brown-headed cowbird and the European cuckoo are the classic parasitic birds, laying their eggs in the nests of other bird species and leaving the chick-rearing to another parent.
All this evidence points to a single conclusion: Cowbird eggs should be left alone. It can be disturbing to observe what looks like “cheating” at the expense of less common species—but it’s just nature’s way, even if it’s ugly.
Officially, the answer is that it is illegal to remove a brown-headed cowbird egg from a nest. They are a native species and therefore protected under the Migratory Bird Treaty–unless you have a depredation permit from the federal government to remove them as in the case of Kirtland’s warblers.
Both male and female Brown-headed Cowbirds make a variety of whistles, clicking and chattering calls. You’ll often hear flight whistles, which are a series of 2–5 clear sweeping whistles with occasional buzzes or trills mixed in. Females make a distinctive rolling chatter that is very attractive to males.
Research has shown that the female common cuckoo is able to keep its egg inside its body for an extra 24 hours before laying it in a host’s nest. This means the cuckoo chick can hatch before the host’s chicks do, and it can eject the unhatched eggs from the nest.