A team of researchers headquartered at the University of Massachusetts Amherst has recently discovered that fear plays an important, unrecognised role in the underdevelopment, and increased vulnerability, of backyard songbirds.
Scientists have long known that urban songbirds face a host of increased challenges, from habitat loss to altered food sources and a larger population of predators, such as skunks, rats, squirrels and, especially, house cats, compared to their rural cousins. In particular, urban nestlings weigh significantly less than those born in the country and have a decreased chance of surviving to adulthood, as a result. New research, published in the journal Ecosphere, helps to tease out exactly why.
Part of the difficulty in figuring out why urban nestlings struggle is due to what biologists call the “predation paradox:” though there are increased numbers of predators in urban areas, there is actually a lower per-capita rate of predation. “The key,” says Aaron Grade, the paper’s lead author who completed this research as a graduate student in UMass Amherst’s program in organismic and evolutionary biology, “has been hiding in plain sight. We haven’t been paying enough attention to fear itself.” MORE
Header image: Adult house wren with food for its nestlings. Credit: Lucy Zhang.