Blackbirds that aggressively defend their nests are loathe to attack rattlesnakes, even though these venomous serpents haven’t been seen in western Oregon since the 1800s. Researchers examined how red-winged blackbirds (Agelaius phoeniceus) responded to different nest predators in Oregon like scrub jays (Aphelocoma californica), ground squirrels, rattlesnakes, cowbirds (Molothrus ater) and nonvenomous gopher snakes (Pituophis catenifer). They used lifelike fakes of these creatures, placing them on platforms near blackbird nests. Blackbirds are known as aggressive nest defenders. But in dozens of tests, blackbirds only struck one rattlesnake decoy, while they attacked gopher snakes dozens of times. But they still acted aggressively, swooping to scare the rattlesnakes off just as much as they did with gopher snakes. “We don’t know whether that’s because they recognized the danger or if there’s something about the viperid features or the rattle that gave the birds pause,” said Shelby Lawson, a postdoctoral researcher in integrative biology at Oregon State University and the lead author of the study published recently in Behavioral Ecology.
