Brown-headed Cowbird

• reproducciónLike the European cuckoo, it lays its eggs in other birds' nests to be incubated and reared by foster parents, and builds no nest of its own.
• It is a brood parasite of more than 220 different species, the widest repertoire known in any bird: a single female can lay more than thirty eggs in a season, spread among other birds' nests.
• It used to follow the bison herds across the prairies, eating the insects they flushed: that wandering life made tending a nest impossible, and brood parasitism was the answer.
• The chicks do not learn the song of their foster parents: they recognise their own kind through an innate password call that sends them looking for other cowbirds once they are independent.

Skeleton type

Vertebrate - internal bony skeleton (bird)

Habitat and environment

Grassland, woodland edges, pasture with livestock and farmed areas of North America

Birth weight

Altricial: born blind, naked or with sparse down and entirely dependent

Size at birth

Born altricial in the nest of another species, which raises it as its own

Sexual maturity

12 months

Gestation / incubation

11 days

Litter / clutch size

1 egg

Sources consulted: https://en.wikipedia.org/wiki/Brown-headed_cowbird

Best time: From April to July in North America, when the females watch the nests of other birds in which they will lay their eggs.