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Southwestern bird populations in steep decline

Report shows that even many common species are dwindling

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Global warming threatens ptarmigan habitat in the mountains of the West.

Staff Report

FRISCO — Bird populations are dwindling all over North America, especially in the Southwest, where some species have declined by as much as 48 percent since the late 1960s, according to the 2014 State of the Birds report released last week.

In Utah, Arizona and New Mexico, habitat loss and fragmentation due to development are the largest threats. These are also significant threats in the nation’s grasslands, where breeding birds like the eastern meadowlark and the bobolink have declined by 40 percent since 1968, with the steepest declines coming before 1990, when stakeholders started investing in grassland bird conservation.

And experts say it’s not just rare birds that are vanishing. The report includes a list of 33 common species in steep decline, losing ore than half their global populations over the past four decades — a clear warning sign that birds can undergo a massive population collapse with surprising rapidity. For example, passenger pigeon populations crashed from 2 to 3 billion birds to none in the wild in just 40 years. Continue reading

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Biodiversity: Will the rain crow sing again?

Feds map critical habitat for yellow-billed cuckoo

Yellow-billed cuckoos have nearly been extirpated from the western U.S. Photo courtesy Rocky Mountain Bird Observatory.

Yellow-billed cuckoos have nearly been extirpated from the western U.S. Photo courtesy Rocky Mountain Bird Observatory.

Will yellow-billed cuckoos make a comeback in Colorado?

Will yellow-billed cuckoos make a comeback in Colorado?

By Summit Voice

FRISCO — The long endangered species odyssey of the yellow-billed cuckoo may be one step closer to resolution, as federal wildlife officials this week proposed designating more than half a million acres of critical habitat for the birds, sometimes known as rain crows for their habit of singing before a storm.

The bird was once common along most rivers and streams in the West, but the decline of the species, eyed for protection since 1986, shows how much human activities have degraded riparian riverside habitat. Yellow-billed cuckoos are neotropical migrants that winter in South America and nest along rivers and streams in western North America. Continue reading

Environment: Another silent spring?

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Systemic neocotinoid pesticides are starting to affect bird populations, according to research.

Neonicotinoid use linked with decline in bird populations

By Summit Voice

FRISCO — Populations of some insect-eating bird species are declining in areas where scientists measured high concentrations of a widely used neonicotinoid pesticide.

In some cases, bird numbers are dwindling by as much as 3.5 percent annually, according to the new study by researchers with Radboud University in Nijmegen and the Dutch Centre for Field Ornithology and Birdlife Netherlands. Continue reading

Environment: Changes in precipitation may drive birds response to global warming

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New model unravels some of the complexities of how wildlife will respond to global warming

Staff Report

FRISCO — Populations of familiar backyard birds like the rufous hummingbird and evening grosbeak are declining, a trend that may be linked with changes in precipitation patterns across the western U.S.

Scientists studying the changes with a new model say precipitation, rather than temperature, may be the the main factor in determining how birds will respond to climate change.

Several past studies have found that temperature increases can push some animal species – including birds – into higher latitudes or higher elevations. Few studies, however, have tackled the role that changes in precipitation may cause, according to Matthew Betts, an Oregon State University ecologist and a principal investigator on the study. Continue reading

Where have all the blue-footed boobies gone?

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Galápagos Islands blue-footed boobie populations have dwindled by a third since the 1960s. Photo via Wikipedia under a Creative Commons license.

Scientists track decline of iconic Galápagos birds

Staff Report

FRISCO — Populations of blue-footed boobies, one of the Galápagos Islands iconic species, have dwindled by a third since the 1960s, mainly because the birds don’t seem to be finding the food they need to breed and raise chicks.

The population decline is so steep that the birds are in danger of dying out, according to a new study published in the journal Avian Conservation and Ecology. The researchers found that sardines have all but disappeared from the birds’ diet, said Wake Forest University biology professor Dave Anderson. Without that primary food source, adult birds are simply choosing not to breed, he said. Continue reading

Study: Birds have highly developed weather ‘radar’

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Study offers new insight into long-distance avian migration.

‘We think that these behaviors represent a previously unknown cognitive ability …’

Staff Report

FRISCO — Some migrating birds may be able to sense weather patterns on a hemispheric scale, helping them optimally time their nonstop transoceanic flights.

Bar-tailed godwits, the ultra-marathon champions of migration, breed in Alaska and spend winters in New Zealand and a recent U.S. Geological Survey-led study suggests that these birds can sense broad weather patterns.

Careful monitoring of the birds suggest they time their departure  to match the best possible atmospheric wind conditions possible within a two-week window. Remarkably, not only were the conditions optimal for take-off, but they almost always provided the best possible conditions for the birds’ entire flights, as far as 7,000 miles in eight days between Alaska and New Zealand.

Continue reading

Study: Eastern chickadee populations moving fast in response to global warming

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Some bird populations are shifting fast in response to climate change. bberwyn photo.

‘The rapidity with which these changes are happening is a big deal’

*More Summit Voice stories on birds and climate change here.

By Summit Voice

FRISCO — Watching climate change is a little more subtle than just sitting around watching a thermometer, but sometimes even scientists are surprised at just how fast things are changing.

A group of East Coast university researchers probably felt that way as they studied the breeding areas of Carolina and black-capped chickadees. Along a narrow zone in the eastern U.S., the two species interbreed, and that overlap zone is moving northward at 0.7 miles per year — a full-on sprint by geological time standards. Continue reading

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