http://www.digitaljournal.com/tech-and-science/science/hundreds-of-thousands-of-migratory-birds-found-dead-in-western-us/article/578043

Hundreds of thousands of migratory birds found dead in Western US

Posted Sep 15, 2020 by Karen Graham
Biologists at New Mexico State University are trying to find out what is causing a mass mortality event among migratory birds. Hundreds of thousands of dead birds have been found from California to Texas, across the U.S. Southwest since August 2020.
File photo: A Green Honeycreeper (Chlorophanes spiza) in Colombia  home to the greatest diversity of...
File photo: A Green Honeycreeper (Chlorophanes spiza) in Colombia, home to the greatest diversity of birds in the world
Luis ROBAYO, AFP
Martha Desmond, a professor at New Mexico State University’s Department of Fish, Wildlife and Conservation Ecology, told CNN the mystery started on August 20 when researchers found a large number of dead birds at the U.S. Army White Sands Missile Range and White Sands National Monument.
At first, it was thought the discovery of the migratory birds was an isolated incident, however, when hundreds of dead birds began turning up in other areas of the state, including Doña Ana County, Jemez Pueblo, Roswell and Socorro, the researchers realized they had a serious problem on their hands.
Residents and biologists reported seeing birds acting strangely before they died. For example, birds that are normally seen in shrubs and trees have been spotted on the ground looking for food and chasing bugs. Many were lethargic and unresponsive so they were getting hit by cars, Desmond said, in numbers "larger than ever seen before."
"It's just terrible," Desmond told CNN. "The number is in the six figures. Just by looking at the scope of what we're seeing, we know this is a very large event, hundreds of thousands and maybe even millions of dead birds, and we're looking at the higher end of that."
What is really intriguing is that resident or local birds have not been affected, said Trish Cutler, a wildlife biologist at White Sands Missile Range, according to The Hill.
Species represented among the dead include warblers, bluebirds, sparrows, blackbirds, flycatchers, and the western wood pewee, to name a few. "A number of these species are already in trouble," Desmond said, according to the Las Cruces Sun News. "They are already experiencing huge population declines and then to have a traumatic event like this is – it's devastating."
The evidence or lack of it
"People have been reporting that the birds look sleepy ... they're just really lethargic," Cutler said. But it is really strange that so many different species of migratory birds are dying rapidly and it is not immediately clear why, although the cause appears to be recent.
Desmond points out that the birds appear to have recently moulted, in preparation for the migration, "and you have to be healthy to do that; but somewhere after that, as they initiated their migratory route, they got in trouble."
The biologists think the wildfires in the western states and the near-drought conditions in areas of the Southwest may have something to do with the mortality event. "Birds who migrated before they were ready because of the weather might have not had enough fat to survive," Desmond said. "Some birds might have not even had the reserves to start migrating so they died in place."
Incredible view of the fire running up the ridge in the Mt Vaca area. Residents north of Vacaville s...
Incredible view of the fire running up the ridge in the Mt Vaca area. Residents north of Vacaville should remain alert about this situation.
Cal Fire Scanner
The bodies of the dead birds are being sent to the US Fish and Wildlife Service Forensics Laboratory in Oregon for necropsies to determine their cause of death, but this could take several weeks.
"This is devastating. Climate charge is playing a role in this." Desmond said. "We lost 3 billion birds in the US since 1970 and we've also seen a tremendous decline in insects, so an event like this is terrifying to these populations and it's devastating to see."
Southwest Avian Mortality Project
One of the world's most popular nature apps is iNaturalist. iNaturalist is an online social network of people sharing biodiversity information to help each other learn about nature, however, it is more than that. iNaturalist is a joint initiative by the California Academy of Sciences and the National Geographic Society.
It's also a crowdsourced species identification system and an organism occurrence recording tool. You can use it to record your own observations, get help with identifications, collaborate with others to collect this kind of information for a common purpose, or access the observational data collected by iNaturalist users.
iNaturalist started the Southwest Avian Mortality Project in August amid the reports of dead birds showing up in New Mexico. Interestingly enough, because of increasing awareness, reports have also come from Arizona, Colorado, Texas and other western states.
To date, with 181 observers or citizen scientists, 238 observations have been recorded across the Southwestern U.S.