Photo courtesy Charles Martinez
This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the brown-headed cowbird.
Some bird groups increase their reproductive success by sticking to the saying of not putting all your eggs in one basket. This prevails practice amongst lots of waterfowl types which frequently slip some eggs into each other’s nests. Cowbirds take this habits one action even more by being obligate brood parasites who never ever build nests, rather transferring all their eggs in the nests of other types.
When bison herds wandered the fantastic plains, brown-headed cowbirds followed to consume the pests that they flushed. It is unidentified if the uncommon reproductive method of the cowbird was an outcome of, or preceded and enabled, these nomadic motions.
More than 220 types of birds have actually been discovered functioning as hosts to cowbird eggs. Typically, cowbird eggs hatch faster, and the nestlings establish faster than those of the host bird. Eggs and young of the host might not endure their aggressive nestmate. Some bird types acknowledge cowbird eggs in their nests and destroy them, however a lot of wind up raising these strange-looking young as their own. It is not uncommon to discover a little mom bird overshadowed by the cowbird recently established it feeds.
Female cowbirds might lay up to 40 eggs in as various nests over a two-month reproductive season, however typically just 3 percent of these produce a bird that makes it through to the adult years. Females find host nests by looking for nest-building activity by other birds and slipping in to lay an egg when the resident bird is away. A female might go back to host nests often times to examine the status of her eggs and young.
Brown-headed cowbirds primarily consume the seeds of yards and weeds. If you spread seed for ground feeders in your lawn, anticipate to discover brown-headed cowbirds there in summer season. They are little members of the blackbird family, males shiny black with brown heads and women colored a plain, dirty brown.
Although they are frequently damned and have actually triggered population decreases in some host types, brown-headed cowbirds are interesting members of our birds of summer season.
For info on occasions, see www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.
