TIL that the brown-headed cowbird is an obligate brood parasite; it lays its eggs in the nests of other small birds. Once hatched the young cowbirds are fed by the host parents at the expense of their own young. More than 140 different species of birds are known to have raised young cowbirds.

Read more: https://en.wikipedia.org/wiki/Brown-headed_cowbird#Brood_parasitism

What do you think?

12 Points
Upvote Downvote

One Comment

Leave a Reply
  1. A fascinating animal:

    Brown-headed cowbirds seem to periodically check on their eggs and young after they have deposited them. Removal of the parasitic egg may trigger a retaliatory reaction termed “mafia behavior”. According to one study the cowbird returned to ransack the nests of a range of host species 56% of the time when their egg was removed. In addition, the cowbird also destroyed nests in a type of “farming behavior” to force the hosts to build new ones. The cowbirds then laid their eggs in the new nests 85% of the time.

Leave a Reply