Birds silenced
Piñons dying off in the Jemez due to climate change have reduced the population
The sweet sounds of songbirds are sliding toward silence following a massive piñon tree die-off on a local, high-altitude shelf of land.
And scientists believe what happened on the Pajarito Plateau may be a harbinger of things to come throughout the high-desert Southwest, where piñon trees — and the birds that frequent them — are potential markers for the effects of global warming.
Jeanne Fair, a Los Alamos National Laboratory ornithologist in the BioScience Division, and other LANL scientists recently released the results of a 10-year bird study on the plateau which shows “a 73 percent decrease in abundance and a 45 percent decrease in richness (variety of species) from 2003 to 2013.”
The irony that the Pajarito Plateau, tucked in the Jemez Mountains, is named after the Spanish term for little birds, was not lost on Fair as she sat in her office last week.
“It has always had special meaning to me,” she said.
But the literal translation, Fair said, may be transcended by the proverbial reputation attached to birds, which “can be very important bio-indicators — so they really can be the canary in the coal mine.”
After the Cerro Grande Fire in May 2000, the lab thinned trees in the area to lessen fire danger. A drought soon followed, and piñon stands were weakened, then attacked, by bark beetles.
The trees were healthy when the study began, but by 2004 they were mostly dead. Fair and her associates did bird counts on thinned areas on the lab and unthinned areas on the nearby Bandelier National Monument and found “no significant differences” between the two. Technical Area 51, a lab environmental research area where part of the study was done, is “one of the most studied plots of land on Earth for piñon-juniper habitat,” said Fair.
“We could see that immediately that the birds in both areas — so thinned and unthinned decreased — this large percent,” she said. “What they both have in common is that the piñon trees died.”
The study concludes tree die-offs are expected to take place worldwide “due to climate-induced drought and increasing temperatures” and the result “may be a significant threat to bird communities in the southwestern U.S. and tree thinning to control fire may be an added risk.” In the study, just published in the
Biological Conservation journal and Audubon magazine, Fair was assisted by LANL wildlife biologist Charles Hathcock and postdoctoral ecologist Andrew Bartlow.
For Hathcock, the takeaway is the decade it required for the work. “We can only detect these types of changes with long-term data sets,” he said.
The U.S. Forest Service and Bandelier National Monument collaborated in the early stages of the research on the sprawling, 10-canyon plateau, which measures roughly 100 square miles. “It’s a very said irony that a plateau named for its bird abundance is now showing such a decline in bird species,” said Jon Hayes, vice president and executive director of Audubon New Mexico, based at the Randall Davey Audubon Center in Santa Fe.
Hayes, who is a biologist, has seen the study and said “these types of stories are all too common and will continue to be until we start to address climate change and habitat loss.
“The fact that they are seeing decreased numbers of them is troubling because these are not rare birds,” said Hayes. “The pinyon jay is a huge one, that is the one we are most concerned with.”
Pinyon jays have a “mutualistic relationship” with the piñon, New Mexico’s state tree, and are a prime food source for the birds, said Hayes. The jays also disperse the tree’s seeds and are partly responsible for the pinon’s wide range. “When we see less jays we know that ecosystem isn’t doing well,” he said.
The jay is listed in the U.S. Fish and Wildlife Service’s Birds of Conservation Concern report, as well as other sensitive species lists.
Getting up with the birds is a prerequisite for ornithologists, and Fair and her associates hit the field at 5:30 a.m. checking on nine different sites, once a summer in June.
At each site, researchers went to three different counting areas, listening for 10 minutes and recording every bird seen or heard.
Piñon trees are under threat worldwide, said Hayes. Numerous studies show piñon die-off from drought and bark beetle attacks cover a huge swath of the Southwest — from “Santa Fe to Flagstaff and everything in between,” said Fair.
“Pinon-juniper is the third largest vegetation type in the continental U.S.,” the study states.
“Predictions are that there will be almost complete loss of conifers [trees with cones and evergreen, needle-like leaves] in the Southwest by the year 2100.”
The piñon loss “is not an issue specific to the Pajarito Plateau,” said Hayes. “The entire Southwest is seeing these die-offs and I would expect that similar bird number declines are occurring as well.”
Climate change, Fair noted, “adds to the conversation; it slightly makes this study or this paper more important.”
If tree die-off predictions are true, “we need to start understanding or predicting the potential impact on different bird populations or different wildlife in general,” she said.
For 40 years the lab has been studying what causes trees to die, but Fair’s study was not meant to determine why birds need trees , but rather to quantify numbers of individual birds and the number of species.
“These birds or these bird communities are telling us something,” she said. “We were very sad the day we saw the [study] data,” she said, adding people should take notice “because of the scenarios which are on the table now.”