The ability of feathers to perform many functions either simultaneously or at different times
throughout the year or life of a bird is integral to the evolutionary history of birds. Many …

Birds have many kinds of internal and external parasites, including viruses, bacteria and
fungi, as well as protozoa, helminths and arthropods. Because parasites have negative …

Sexual and asexual reproduction are found throughout the plant and animal kingdoms.
Asexual reproduction has its advantages, chief among which is that it does not require the …

The first comprehensive review of all aspects of the biology of moult, drawing information
from across the literature and in all birds, from penguins to passerines. Feathers are …

Birds are plagued by an impressive diversity of ectoparasites, ranging from feather-feeding
lice, to feather-degrading bacteria. Many of these ectoparasites have severe negative effects …

Animal camouflage represents one of the most important ways of preventing (or facilitating)
predation. It attracted the attention of the earliest evolutionary biologists, and today remains …

The uropygial gland is a holocrine complex exclusive to birds that produces an oleaginous
secretion (preen oil) whose function is still debated. Herein, I examine critically the evidence …

Some birds undergo seasonal colour change by moulting twice each year, typically
alternating between a cryptic, non‐breeding plumage and a conspicuous, breeding …

Sexual dimorphism is presumed to reflect adaptive divergence in response to selection
favouring different optimal character states in the two sexes. Here, we analyse patterns of …

Plumage color can be considered as a social signal in chickens and a breeding
identification tool among breeders. The relationship between plumage color and trait groups …