Hungry as a whole brood, the outsize baby devours everything brought by its foster parents—in the photo ... observed the birds’ behavior in 2014 in Amsterdam, where she lives.

Brood parasitic birds lay their eggs in the nests of others ... nestlings can stimulate higher rates of provisioning by host parents by serving as a supernormal stimulus and enabling parasites ...

Some species of cowbirds don't appear to be the best parents. For example ... Both species are brood parasites - they lay their eggs in the nests of other birds. Brown-headed cowbirds are native to ...