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Are Homebody Warblers More Likely to Sing Together?

Scientists who want to study the evolution of behavior face a fundamental problem: unlike bones, behavior generally doesn’t fossilize. However, that doesn’t mean that extinct species’ behavior doesn’t leave any evidence. The behavior of living or “extant” species can give us clues about the behavior of their ancestors, and we can use the behavior of living species, the evolutionary relationships among species, and computational modelling to make inferences about extinct species’ behavior.

scrub-jay specimens
Devon DeRaad lines up Woodhouse’s Scrub-Jays (left) and Sumichrast’s Scrub-Jays (right) to compare back color between the forms. Photo by John McCormack.

How Do Traits Change Across a Scrub-Jay Hybrid Zone?

Where should we draw the line between species? Biologists have debated this question for over 100 years. For much of that time, Ernst Mayr’s Biological Species Concept, which defines a species as a group of individuals that is reproductively isolated from other groups, has dominated the conversation. Recently, however, more and more evidence of hybridization between species has accumulated, especially in birds.

volunteer observing shorebirds
A Delaware Shorebird Project volunteer scans a flock of foraging shorebirds looking for leg flags. Photo by Jean Hall.

Resighting Errors Are Easy to Make and Hard to Measure

Color bands, leg flags, and other field-readable marks are a core component of the ornithologist’s toolkit. Mark-resight studies have led to invaluable insights into the demographics, movements, territoriality, and migration patterns of birds. But clear, confident IDs can be hard to obtain in the field. Colors are difficult to distinguish in low light or when worn, alphanumeric codes are easily mis-remembered or mis-recorded, and was it blue on the left, red on the right, or the other way around?

Tracking Cultural Evolution in House Finch Song, Part 1

The first bird song I ever recorded was that of a House Finch. When I was a kid growing up in Leominster, Massachusetts, the bird that nested behind my front porch lamp would fly out to a particular birch tree or the telephone wire and belt out a complex four-second warble over and over again.

marbled godwit
A newly banded Marbled Godwit. Photo by Dan Ruthrauff.

How to Hide a Godwit

Marbled Godwits are common and conspicuous North American shorebirds. On its prairie breeding grounds, the godwit’s raucous call and proud flight display alerts all to its presence, and the species is equally obvious on its temperate nonbreeding grounds along both the Atlantic and Pacific coasts due to its gregarious nature and telltale alarm call. So how did such a charismatic species go largely undetected in Alaska until the 1980s?

burrowing owl nestling
Collecting samples from a Burrowing Owl nestling. Photo by John Kelly, Boise State University.

Do Burrowing Owls Disperse Plague-Infected Fleas?

Western Burrowing Owls (Athene cunicularia hypugaea) and Pulex irritans, the so-called human flea, have a curious host-parasite relationship. Although we’ve known about it for some time, many details of their connection remain unclear, including why it appears mainly in the northwestern portion of the Burrowing Owl’s range despite the fact that both species have much broader geographic distributions.