More than 1,300 bird species across the globe face extinction, driven by the loss of places to live and breed. In La Plata County, three birds are in worrying decline, their futures uncertain.
For each bird, the impacts of human hands on the landscape have caused the destruction or disappearance of habitat, which has led the U.S. Fish and Wildlife Service to list the animals on its endangered/threatened list.
An endangered listing is any species in danger of extinction through all or a significant portion of its range, whereas a threatened listing is any species that is likely to become endangered within the foreseeable future.
This story is the second installment of a three-part series that covers the state of species on the endangered/threatened list in La Plata County. A previous story covered mammals, and the final story next week will look at plants and insects.
Mexican spotted owl (threatened)It’s a rough estimate, but wildlife researchers suspect there are only about 2,100 Mexican spotted owls in the United States, dispersed throughout the mountain ranges and canyon lands of Arizona, Colorado, Utah and New Mexico.
The number of spotted owls in Mexico as well as western Texas is also considered dangerously low.
“Their population is decreasing at an alarming rate,” said Greg Dyson, with Wildearth Guardians. “And that’s because their habitat is decreasing at an alarming rate.”
The Mexican spotted owl, a nighttime hunter, thrives in tree cavities of old-growth forests, swooping down from tree branches to catch its prey of rats, gophers, bats, reptiles and other small critters.
But over the years, clear-cutting and logging has wiped away a significant portion of the spotted owl’s natural environment, causing the Fish and Wildlife in 1993 to list the animal as threatened.
Leslie Ellwood, a biologist with Fish and Wildlife, said since the spotted owl was listed, land agencies, such as the Forest Service and Bureau of Land Management, have re-evaluated management practices.
“There’s been a big effort to change timber management practices that really didn’t leave habitat,” she said.
Yet, despite any gains with revised forest management, a new evaluation of the Mexican spotted owl in 2012 found fire danger was an even bigger threat after years of drought in the 2000s.
As a result, Fish and Wildlife biologist Shaula Hedwall said efforts in recent years have refocused to reduce fire danger in areas where spotted owls are known to live.
Hedwall said that since the spotted owl was listed, the agency has not secured adequate funding to conduct a proper study of population and range boundaries.
However, Fish and Wildlife is in the third year of a 10-year less-costly survey to get a better idea about how many spotted owls are out there. That way, land managers can apply better standards.
“Funding is difficult to obtain for a lot of this work,” Hedwall said. “There’s so many competing elements on the landscape.”
The Mexican spotted owl’s northern range includes areas of Southwest Colorado in La Plata County, areas near Mesa Verde as well as on Southern Ute Indian Tribe land. The population here has not recovered as well as those in Arizona and New Mexico, Ellwood said.
“We’ve seen a decline, and we don’t know why,” Ellwood said. “Potentially, that drought we had a while ago reduced rodent populations. Or, there could just be natural population fluctuations.”
Wildearth Guardian’s Dyson said the organization has filed a lawsuit that would require Fish and Wildlife to come up with better management practices for the spotted owl.
“What we’re asking for is better science,” said Dyson. “I’m worried we’re past the point of no return, but because we know so little about the owl, that’s just such a dire conclusion to come to. I feel like we need to hold out hope as long as we can.”
Southwestern willow flycatcher (endangered)Greg Beatty, a biologist with Fish and Wildlife, said there’s a long list of reasons why the southwestern willow flycatcher – a small, insect-eating bird – is on the verge of extinction.
But the primary reason, he said, was the loss of habitat caused by land and water management, which led to an endangered listing for the bird in 1995. “If you think about the Southwest, one of the more significant alterations that we’ve done to land is that we’ve managed rivers for urban and rural needs,” Beatty said. “Communities and agriculture, in particular.”
The southwestern willow flycatcher lives in the willows of wide forests that grow in broad floodplains, typically at the bottom ends of rivers. The bird has strongholds in Arizona and New Mexico, but populations have been documented in Southwest Colorado, south of Vallecito Lake.
Throughout the early 1900s, the entire American Southwest was subject to a rapid pace of damming, water diversions and construction of levees that altered historical river flows.
“All these manipulations to rivers have affected the abundance and quality and distribution of trees that grow alongside these rivers,” Beatty said. “That is really affecting the habitat of the flycatcher, and it’s the primary reason why it was listed.”
Before its listing, there were about 300 known territories of flycatchers, Beatty said. Now, Fish and Wildlife is familiar with more than 1,000 – though it’s unclear whether that’s a result of increased monitoring or the population rebounding.
Recovery efforts have included better grazing management, by diverting cattle away from rivers and streams, banning ATVs from delicate riparian habitat, as well as applying better management tactics for ground water.
But Jen Pelz, wild river program director for Wildearth Guardians, said more than 85 percent of the flycatcher’s population is located near Elephant Butte Reservoir, two hours south of Albuquerque along the Rio Grande River.
With such a high concentration of the birds in one location, she said the species as a whole is at risk.
“What if something happens at Elephant Butte?” Pelz said.
“You need to have that diversity to make sure a species doesn’t go extinct at some point. It’s really important, even in Colorado with a smaller population, that those birds are protected.”
Pelz also pointed out that if climate change does indeed bring drier, drought-plagued years, the flycatcher’s riparian habitat could disappear.
“They are not recovered by any means,” she said. “They’re vulnerable.”
Fish and Wildlife’s Beatty said more monitoring efforts will take place in the next few years. He said it’s critical to know where the birds are, where they’re thriving and where they’re declining.
“There are areas of the bird’s range where things right now numerically going really well, but other parts of the range have not done as well,” Beatty said. “There still are issues and growing concerns, but right now we’re a lot better off than we were 20 years ago.”
Yellow-billed cuckoo (threatened)Much like the southwestern willow flycatcher, the yellow-billed cuckoo suffers from habitat loss because of water-use practices tied to agriculture and development.
Yellow-billed cuckoos are slim, long-tailed birds with dark upper parts and white under parts, about 12 inches in length. Their historic breeding range once covered the entire American West, west of the Continental Divide. Yet, these days, the methodical foraging critter is a rare, if non-existent sighting.
The yellow-billed cuckoo had been up for an endangered/threatened evaluation for years, but because of Fish and Wildlife’s workload, consideration had been delayed, said Susan Sferra, a Fish and Wildlife biologist.
Yet, a lawsuit filed by several environmental groups sped up the process, leading to the bird’s listing in 2014.
Because the listing is so new, Sferra said the agency is in the surveying stage, identifying where the species lives and how many birds there might be. There are major gaps in population numbers, she said.
“During that process, we’ll find out a lot more about habitat requirements,” she said. “Then we’ll gather a list of things we could be doing to help them recover.”
Yellow-billed cuckoos prefer riparian habitats but are also sturdy enough to inhabit more arid areas, including mesquite woodlands and evergreen forests.
Various efforts, such as habitat restoration and changing grazing practices, have been pursued in the short term. But now that the bird is federally protected, any new project on public land will have to evaluate its impact to the species.
“If we take care of our rivers, that would be positive for yellow-billed cuckoo,” Sferra said. “The challenge will be climate change, and also population growth, and how we as a society use our water.”
Wildearth Guardian’s Pelz said yellow-billed cuckoos share many of the same problems as the southwestern willow flycatcher as the impacts of human development change the face of the American Southwest.
“They all suffer from the same problems,” she said. “We’ve over managed rivers where they aren’t serving ecological purposes they once did. And nothing will change unless there’s some obligation to those agencies to manage water differently, and that’s beauty of the Endangered Species Act.
“Hopefully, we’ll get new restrictions on new projects to encourage that activity.”
jromeo@durangoherald.com