The recent wet and windy weather killed or injured many Oregon’s Barn and Violet-green Swallows.
On Oct. 1, veterinarians for the Oregon Department of Fish and Wildlife received multiple calls from Oregon residents about dead and dying swallows. Reports have come from the Port of Saint Helens to as far south as Junction City.
Groups of from 10 to 200 swallows were reported dead or near death in barns and other structures where they perch, according to a press release from OFDW. Mortality appears to be greater closer to rivers and standing water where the birds concentrate.
Colin Gillin, ODFW State Wildlife Veterinarian, estimates that thousands of birds have died, he said in the release.
“This type of mortality event is unprecedented and considered a rare and unusual event,” Gillin said. “The effect on bird populations is unknown.”
A number of birds were examined at the Oregon State University Veterinary Diagnostic Laboratory and pathologists determined the swallows were thin and had not eaten recently with their cause of death most likely being weather-related starvation, according to the release. Veterinarians believe that four consecutive days of rain and wind prevented the swallows from feeding at a time when they would normally be preparing for winter migration.
Swallows feed on insects during flight and inclement weather events can have an effect on young and weaker birds that cannot take in enough food to meet their energy requirements. Swallows are seasonal migrants to Oregon and migrate to Central and South America during winter.
Sick or dead wildlife may be reported to the ODFW Health Lab at 1-866 968-2600. Only licensed wildlife rehabilitators may treat sick or injured wildlife. See ODFW’s website for a list of licensed wildlife rehabilitators.