ALBUQUERQUE – A large number of migratory birds are falling dead around New Mexico as scientists struggle to figure out what triggers one of the southwest’s largest bird deaths in recent memory.
After people began finding the dead birds in recent days in places ranging from hiking trails to suburban driveways and golf courses, the mystery of what causes the death has intensified.
Biologists are investigating whether forest fires on the west coast may be a factor in the deaths, with smoke joints potentially altering migratory routes or increasing toxins inhaled by birds.
“I’ve never seen anything like it in New Mexico in recent times,” said Martha Desmond, a professor in the Department of Fish, Wildlife and Conservation Ecology at New Mexico State University.
One of the first alarms about the deaths came on August 20, when a report described a sharp rise in dead birds found in the White Sands Missile Range in southern New Mexico, Dr. Desmond.
Since then, Dr. Desmond and other researchers sent reports of dead migratory birds found in many parts of New Mexico as well as in parts of southern Colorado and West Texas. Dr. Desmond said the number of dead birds in the region could easily be counted in the hundreds of thousands.
Trish Cutler, a wildlife biologist at the White Sands Missile Range, told Albuquerque television station KOB over the weekend that fewer than half a dozen dead migratory birds are reported dead at the gun test site in a normal week.
“This past week we’ve had a couple of hundred, so it really got our attention,” Ms Cutler said.
Residents in different parts of New Mexico have increasingly begun sending similar reports in recent days. In a post over the weekend on Twitter, Austin Fisher, an independent journalist in northern New Mexico, recorded video of dead birds he encountered in Velarde while on a snake ride down the Rio Grande.
“I thought to myself, ‘Wait, I’ve never seen so many dead animals in one place in my life,'” Fisher said.
Two doctoral student ornithology students from the University of New Mexico, Jenna McCullough and Nicholas Vinciguerra, later studied the area and collected a total of 305 birds, including 258 violet-green swallows.
“Many of them have little or no fat, many are underweight, and there are not many external signs that they have inhaled much smoke,” Ms McCullough said.
Andrew Farnsworth, a senior research assistant at the Cornell Lab of Ornithology, noted that the outbreak began before the sharp drop in temperature in New Mexico last week. He added that the deaths posed “clearly a bigger and bigger event” in the broader problem of migratory birds being killed, often by cats or by colliding with man-made structures.
“It’s different this year than other years,” said Dr. Farnsworth, adding that he believed fires could be a potential trigger for bird deaths. “We have had lots of hot summers, but very few have had these huge fires combined with heat combined with drought.”
Dr. Farnsworth said particles or toxic compounds from smoke could be a primary factor. He pointed to migration patterns, saying researchers could find similar reports of dead birds, even in northern Mexico and “all the way up the Rockies.”
Many different types of birds have been found dead in New Mexico in recent weeks, including songbirds, swallows and flycatchers. Tristanna Bickford, a spokeswoman for the New Mexico Department of Game and Fish, said it would take a while before biologists could finally determine what caused the death.
Ms Bickford said New Mexico officials had provided samples of the dead birds to the National Wildlife Health Center in Wisconsin for examination. She said it could potentially take months to diagnose the cause if a significant amount of testing was needed.
“This is certainly not a normal thing,” Bickford said.
Meanwhile, Mrs Bickford urged people encountering sick or dead birds to proceed cautiously. She recommended keeping cats indoors to reduce further stress on migratory birds and encouraged people to wear gloves if collecting specimens of dead birds to hand over to game and fish authorities.