Most cooperatively breeding birds live in family groups, in which a breeding pair is assisted
by genetically related “helpers” who do not reproduce. In some species, however, several …

Cooperative groups are ubiquitous in animals, as are the challenges of allocating labor to
accomplish cooperative tasks, including territory defense, hunting, and brood care …

Symbiotic microbes affect the health, fitness, and behavior of their animal hosts, and can
even affect the behavior of non-hosts. Living in groups presents numerous benefits and …

Groups of animals often cooperate on shared tasks, but individual contributions are not
necessarily equal: individuals can specialize on different tasks (division of labour) or vary in …

Gregarious species must distinguish group members from nongroup members. Olfaction is
important for group recognition in social insects and mammals but rarely studied in birds …

Offspring sex ratios may deviate from parity when the fitness benefits of producing male or
female offspring vary. We tested for sex ratio bias in smooth‐billed anis Crotophaga ani, a …

This is the second in a series of articles about the breeding biology of Brazilian birds based
on field work in various regions of the country since the 1980s. The data cover various …

Cooperative groups are highly variable in relatedness and size, but whether this influences
the environments where species live remains unclear. We test the prediction that …

The benefits of cooperative breeding include anti-predator defense, access to resources,
and inclusive fitness via kin-selection. Smooth-billed anis (Crotophaga ani) are communally …

Reproductive competition in the form of ovicide is common in some joint-nesting birds,
species in which multiple females lay eggs in a single nest. Joint-nesting Smooth-billed Anis …