Study Estimates Impact of Climate Change on Southwestern Birds

Habitat destruction is one of climate change's gravest threats. As sea levels rise and animals shift their ranges to find warmer temperatures, it's estimated that 20 to 30 percent of species will be at high risk for extinction by the end of the century. Now, a study from the U.S. Geological Survey is helping us better understand that process in the southwestern states.

The study, led by USGS scientist Charles van Riper, looks at seven species of birds and five species of reptiles, projects significantly more loss of habitat than gains overall. Despite their mobility, birds are up against more precipitous habitat losses and gains than reptiles.

Riper says this study also demonstrates that not every species responds in the same way to climate change. “Some species respond in a positive fashion and some respond in a negative fashion. We have to be careful, everyone wants a silver bullet, a one-size-fits-all, and that’s not what’s going to happen with climate change in the future.”

Of the many species whose habitat is endangered by climate change, four birds’ plights stand out. Here are the four species included in the study that are projected to experience the biggest decline in habitat:

Sage Thrasher

The smallest of the thrashers, this little bird lives in dry sagebrush plains and arid areas such as the floors of rocky canyons, however it winters in dense thickets and lowland scrub.  Though not considered endangered by the International Union of Conservation for Nature (IUCN) because of its large habitat range and healthy population size, the breeding range of the sage thrasher is projected to decrease 78 percent between 2010 and 2099.

Pinyon Jay

The pinyon jay is found in the foothills and lower mountain slopes of the west and southwest United States and in Mexico. As the temperatures continue to rise, the pinyon jay will be forced out of their homes. Already considered a vulnerable species by the IUCN, its North American population has fallen an estimated 74.8 percent in the last 40 years. The major threat to the species is destruction of pinyon-juniper woodland. In years when cone crops fail, pinyon jays disperse far from their usual habitat, gaining them the reputation as one of the most irruptive North American birds. That said, their range is projected to decrease by 25-31 percent between 2010 and 2099.

Pygmy Nuthatch

Found in western United States and Mexico, the pygmy nuthatch is a miniscule bird found in open forests of older ponderosa pines. A peculiar songbird, a pygmy nuthatch will share the burden of raising their brood among its relatives. Climate change will increase the risk of wildfire among these historically resilient trees. As a result, the pygmy nuthatch population is estimated to decrease anywhere from 25 to 31 percent between 2010 and 2099.

Williamson's sapsucker

Unlike other woodpecker species, the male and female Williamson’s sapsucker look very different. In fact, they look so unalike that they were originally thought to be completely different species. This bird has had a stable population over the last 40 years, though that could change if the USGS’ predictions are accurate. This bird has benefited from a very large range, though it is projected to decrease 78 percent between 2010 and 2099.