Warming from climate change is expected to reduce body size of endotherms, but studies
from temperate systems have produced equivocal results. Over four decades, we collected …

Environmental mercury (Hg) contamination of the global tropics outpaces our understanding
of its consequences for biodiversity. Knowledge gaps of pollution exposure could obscure …

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 …

Variation in evolutionary rates among species is a defining characteristic of the tree of life
and may be an important predictor of species' capacities to adapt to rapid environmental …

Determination of a bird's age or cohort is critical for studies on avian demography,
occurrence patterns, behavior, and conservation management. Age designations have …

Insectivores of the tropical rainforest floor are consistently among the most vulnerable birds
to forest clearing and fragmentation. Several hypotheses attempt to explain this pattern …

For decades, ecologists have studied fundamental questions of how Amazonian biodiversity
is maintained, and whether that diversity can persist following deforestation. The long history …

Ornamentation is typically observed in sexually mature adults, is often dimorphic in
expression, and is most apparent during breeding, supporting a role for sexual selection in …

Secondary contact between species often results in the formation of a hybrid zone, with the
eventual fates of the hybridizing species dependent on evolutionary and ecological forces …

Long-distance migratory aerial insectivores are among the most threatened groups of birds
breeding in North America, yet little is published about the two-thirds of their annual cycle …