Recent drought may provide a glimpse of the future for birds in the Sierra Nevada

Many birds respond positively to the warmer climate conditions associated with drought

Date:  February 21, 2019

Source:  Point Blue Conservation Science

How wildlife respond to climate change is likely to be complex. To better understand the effects of climate change on the bird community in the Sierra Nevada region, new research published today from Point Blue Conservation Science examines the impacts to birds from a recent extreme drought (2013-2016). The drought resulted in the widespread death of pine trees due to attacks by bark beetles, potentially impacting wildlife habitat. While the results were varied, researchers found that many bird species responded positively to the climate conditions associated with the drought, potentially offsetting the negative habitat impacts of the dead trees.

Under the assumption that climate conditions and species' responses to those conditions during the drought are similar to those that may occur in the future, researchers assessed the influence of temperature, water deficit, and tree mortality on bird abundance for 45 species. Researchers then used those models to project the effect of climate change on the bird community through the year 2050.

"When we began our research, we were not originally thinking that it would result in a 'climate paper,'" said L. Jay Roberts, Avian Forest Ecologist at Point Blue and lead researcher on the study. "Our hypothesis was that bird populations would decline due to the large-scale tree deaths that resulted from the drought. We were really surprised to see positive bird numbers after the drought and went looking for an explanation. Then, the results started to make sense when we added in the climate data and saw that birds responded more positively to the warmer temperatures than they were negatively impacted by the dead trees and dry conditions."

Overall, the total number of birds in the study area increased during the drought period and the models project similarly high numbers in response to warmer future climate conditions. Nearly half of the species in the study responded positively to temperature increase, while only 20% declined. Roughly one-third of the species declined in response to higher water deficit, while one-third increased. However, many of the species that benefit from increased temperature were also sensitive to high water deficit and tree mortality. Thus, their positive response to increasing temperatures in the future could be offset by drought or habitat change.

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Natural selection and spatial memory link shown in mountain chickadee research

Date:  February 12, 2019

Source:  University of Nevada, Reno

Chickadees with better learning and memory skills, needed to find numerous food caches, are more likely to survive their first winter, a long-term study of mountain chickadees has found.

Enhanced spatial cognition and brain power evolves via natural selection, an elaborate study of hundreds of mountain chickadees in the Sierra Nevada has found. Using passive integrative transponder (PIT) tags in combination with radio frequency identification-equipped feeders, scientists at the University of Nevada, Reno have tracked feeding behaviors and measured learning and memory of these non-migratory birds that live year-round in the high-elevation forest northwest of Truckee, California.

"This is a unique program, set in the wilderness, so we get unique results," Vladimir Pravosudov, lead researcher and biology professor at the University's College of Science, said. "Over the years, we've banded and tagged thousands of chickadees and observed their spatial cognition using custom-designed and built feeders that allow us to track how individuals learn and remember. And now we have tested whether individuals with better learning and memory performance are more likely to survive the winter."

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Rim Fire Logging May Endanger Rare Woodpecker

A plan by the U.S. Forest Service to allow "salvage" logging of almost 30,000 acres of forest burned in 2013's Rim Fire poses an unacceptable risk to a rare woodpecker that relies on habitat created by forest fires.

That's according to a new report by the Center For Biological Diversity (CBD) and the John Muir Project (JMP) detailing the importance of fires to the health of Sierra Nevada forests, as well as the animals and plants that call those forests home.

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Voice software helps study of rare Yosemite owls

YOSEMITE NATIONAL PARK, Calif. (AP) — In the bird world, they make endangered condors seem almost commonplace.

The unique Great Gray Owls of Yosemite, left to evolve after glacial ice separated them from their plentiful Canadian brethren 30 millennia ago, are both a mystery and concern to the scientists charged with protecting them.

With fewer than 200 in existence in this small pocket of the Sierra Nevada, the slightest disturbances by humans can drive the extremely shy birds from their nests, disrupting sporadic mating cycles that ebb and flow annually depending upon food availability.

So this summer, researchers found a way to abandon their traditional heavy-handed trapping, banding and the blasting of owl calls in favor of the kind of discrete, sophisticated technology used by spies and forensic scientists.

They hope to lessen human influence on this subspecies of owls prized for the potential insights their survival offers into habitat-specific evolution.

"Even if it takes only 15 minutes to trap a bird, it's traumatic for them in the long term," said Joe Medley, a PhD candidate in ecology at UC Davis who perfected computer voice recognition software to track the largest of North America's owls. "With a population this small, we want to err on the side of caution in terms of the methods we use to get data."

Medley placed 40 data-compression digital audio recorders around the mid-elevation meadows typically favored by the owl known as Strix nebulosa Yosemitensis, hoping to identify them by their mating, feeding and territorial calls.

Continued:  http://www.fox11online.com/dpp/entertainment/consumer_tech/Voice-software-helps-study-of-rare-Yosemite-owls_03671433