American Birding Podcast



Blog Birding #410

At National Geographic, a comprehensive look at the trade of captured songbirds in south Florida by Dina Fine Maron.

Yet the U.S. Fish and Wildlife Service reports that 40 protected bird species in Florida are routinely trapped, mostly songbirds but also owls and hawks. According to Rene Taboas—an undercover officer who heads the Florida Fish and Wildlife Conservation Commission’s songbird investigations whom we had permission to name—almost all songbird trapping in the state occurs in national parks and on state lands and private property around Miami. According to Florida law enforcement officials who track the trade, it’s done largely by people either born in Cuba, where keeping songbirds is part of the culture, or born in the U.S. of Cuban descent.

What influences the dawn song of House Wren? Sharon Gill, Erin Grabarczyk, and Maarten Vonhof explain what gets these birds to sing at AOS News. 

What might birds tell us? Historically, they might have told us that cool temperatures on cloudy nights delayed the start of dawn singing. Or that female breeding partners were fertile and males were guarding them closely, either by singing more and earlier or singing less and later depending on the particular species. Today, birds might tell us about how they react to changes in their environment: do they sing earlier when the night sky is brighter, or later if it’s noisier at night, at dawn, or throughout the day?

It is not commonly known that New World Warbler pairs sing duets, but it’s a fairly common occurrence. At Avian Hybrids, Jente Ottenburghs takes on this fascinating subject.

Liam Mitchell and his colleagues investigated 107 species of warblers and found evidence for duets in 19 species. When they correlated this behavior with migratory strategies, they uncovered a significant relationship. In line with the prediction outlined above, birds that produce duets tend to be sedentary. The researchers also reconstructed the evolutionary history of duets, revealing that this behavior evolved several times (concentrated in particular genera, such as Myioborus and Myiothlypis). The ancestor of these birds probably did not sing duets.

More on female songs, a singing female Cerulean Warbler opened up a line of questioning for a group of scientists. Tara Sontara tells the story at Audubon. 

It was mid-June, early in the breeding season, and yet the only explanation that Sharp—a former technician and current graduate student studying this species—could imagine was that a male nestling was attempting his first, unskilled song. The next day, Sharp returned with part of his research team from Ball State University, and they heard the same peculiar call. Then the bird peeked out of the nest, and they realized the sound’s source. It was a female, they were shocked to find.

Saltwater and Sparrows are not an uncommon combination, but it’s one that has evolved several times over the millenia as reported by 

“For tidal saltmarsh species, the challenge is how to maintain the right balance between water and salt concentrations in their cells,” explains lead author Jennifer Walsh, a postdoctoral researcher at the Cornell Lab of Ornithology. “When cells are exposed to saltwater, they shrink. If they’re exposed to too much fresh water, they expand. Without the right balance, the cells can die.”