They are white & heavily speckled with brown flecks. You can identify them because there are usually only one or two in a nest and the rest of the eggs are smaller & a different color.
Cowbirds lay their eggs in other birds nests, leaving the young to be raised by the host species.
In North America, cowbirds do this. In Europe, it is a type of Cuckoo that does this.
Cowbirds are considered unusual because they practice brood parasitism, where they lay their eggs in the nests of other bird species, letting those birds raise their young. This behavior can harm the host bird species by outcompeting their offspring for resources. Additionally, cowbirds have evolved to follow large mammals like buffalo in the wild, exploiting the insects stirred up by their movement.
mimicry
Cowbirds lay their eggs in other birds nests.http://www.illinoisraptorcenter.org/cowbirds.html
The relationship is called parasitism. The cowbirds raid the other bird's nest and lay their eggs there. The other bird has to migrate to another tree to build a new nest.
What do koi eggs look like?
A group of cowbirds is known as a "corral" and a "herd" of cowbirds.
Cowbirds do not typically benefit songbirds; in fact, they often harm them. Cowbirds are brood parasites, laying their eggs in the nests of other bird species, which can lead to the songbirds raising cowbird chicks at the expense of their own. This can reduce the reproductive success of the host songbird species, as they may abandon their own eggs or invest resources in the larger, more demanding cowbird chicks. Overall, the relationship is generally detrimental to songbirds.
They are small round eggs that look like deer scat
Cuckoos and cowbirds are famous for laying their eggs in other birds' nests, and leaving the chicks to be raised by the other birds.
What you saw was more likely a wren feeding a Brown-headed cowbird. Cowbirds are dark in color like crows but as adults are more blackbird-like in size. Cowbirds often lay their eggs in the nests of songbirds and allow them to hatch and raise the cowbird fledglings. This is a behavior known as brood parasitism and is normal for cowbirds. A cowbird fledgling oftentimes grows to become larger than the host parent that is raising it.