Area’s Birds Losing Ground, Group Warns

By TONY DAVIS

Birds at risk

Christmas counts to begin Friday at Buenos Aires

As hundreds of Southern Arizonans gear up for another round of Christmas bird counts, the group that sponsors them warns that many beloved birds living in this region are on the downswing.

Eleven species living in Arizona earned a spot on a national “red list” of 59 imperiled birds compiled by the National Audubon Society and the American Bird Conservancy. Also living in Arizona are 36 of 119 birds that made the groups’ “yellow list” of troubled birds facing less-imminent threats.

A half-dozen Southeast Arizona species – many commonly seen by local birders – were ranked in greatest risk in this region by an official with the statewide Audubon Arizona chapter. They’re considered threatened by development, global warming, overgrazing, water pumping, reservoirs, invasive species, fire and drought.

The first of 14 Christmas counts in Southern Arizona is Friday at the Buenos Aires National Wildlife Refuge, followed by Avra Valley on Saturday and the Tucson area on Sunday. Participants pay $5 each to cover costs of administering counts within a specified boundary. In Tucson, it spans a 7.5 mile radius of the intersection of Oracle and River roads.

Only two of the six most imperiled birds – the endangered Southwestern willow flycatcher and the threatened Mexican spotted owl – are in enough trouble to have federal protection. Others are common, with 1.2 million gilded flickers and 1.5 million Bell’s vireos prime examples.

Such species were chosen because their numbers drop significantly each year or because they face major threats to their habitats, said Tice Supplee, Audubon Arizona’s director of bird conservation.

For most, “Their situation is serious, but we’re not talking about serious in the form of extinction,” said Scott Wilbor, a conservation biologist for the Tucson Audubon Society. “Their populations are indicating that we still have time, but if we don’t do anything we are going to find these species relegated to small pockets.”

Of the six species, Supplee pegged the flycatcher as in the most jeopardy, because of its small numbers and dependence on fragile cottonwood-willow riverfront riparian areas. In particular, the United States Geological Survey rates the flycatcher as vulnerable to global warming.

Riverfront vegetation is dramatically affected by water availability, said Mark Sogge, a survey biologist. If global warming brings less rainfall along with increased temperatures, that could harm these areas and cut into the bird’s habitat, he said.

Recent federal and state surveys found 1,264 flycatcher nesting territories of one or two birds in Arizona and five other Southwestern states. In Southeast Arizona, they’re most easily found along the lower San Pedro River, north of San Manuel.

Twelve years after the tiny bird landed on the endangered list, the number of known territories has risen from 300 or so and is approaching the 2,000 needed to achieve recovery. Experts disagree over whether that’s due mainly to increasing populations or better surveying.

But the U.S. Fish and Wildlife Service warns that the bird still has a long way to go otherwise. The bird is scattered in small numbers across most of its range, with the vast majority of nests jammed into a few hot spots. Nearly half the bird’s population lives in three areas: the San Pedro, Roosevelt Lake east of Phoenix and the Cliff-Gila Valley of Southwest New Mexico.

“Any natural or human-caused catastrophic event that causes loss of one of these sites would instantly reduce the population by 10 to 20 percent,” a service report said.

A flycatcher disaster occurred in Roosevelt in 2005 when heavy rains swelled reservoir levels, inundating tamarisk and willow trees where the bird lives. From 2004 to 2006, nesting territories dropped 47 percent to 111, more than wiping out gains elsewhere in Arizona. In areas surveyed in 2005 and 2006, the number of territories dropped 11 percent statewide.

Greg Beatty, a Fish and Wildlife Service biologist, saw a silver lining in Roosevelt’s tree drownings: The flooding eventually will nurture the growth of young trees and shrubs where the bird can live once the water recedes.

Without flooding, the existing trees would age and no longer be suitable for flycatchers, he said.

But Beatty is confusing natural river flooding, which actually creates bird habitat by uprooting trees, moving around sandbars and dispersing seeds, with flooding by artificial reservoirs that systematically drowns trees, said Kieran Suckling, science director of the Center for Biological Diversity, an environmental group.

Southwestern willow flycatcher

Appearance: a little less than 6 inches long, brownish-olive to gray-green body. Living space: mainly low-elevation, dense willow, cottonwood and tamarisk thickets along rivers. Range: Arizona, Southern California, Nevada, Utah, New Mexico and Colorado; winters in Mexico. Population: about 1,250 territories, one to two birds per territory, trend uncertain. Threats: water pumping, overgrazing, global warming, drought, fire, tamarisk removal and inundation by rising reservoirs.

Mexican spotted owl

Appearance: about 17.5 inches long with a 40-inch wingspan. Mostly chestnut-brown. Living space: old-growth pine and fir forests. Range: Arizona, New Mexico and southern Colorado and Utah. Population: estimated from 800 to 2,300, stable in Arizona, declining in New Mexico. Threats: logging, drought and global warming.

Virginia’s warbler

Appearance: about 4.5 inches long. Living space: pinon-juniper and oak woodlands. Range: Arizona, New Mexico, Nevada, Utah and Colorado, winters in Mexico. Population: 410,000, declining about 0.4 percent annually. Threats: clearing of habitat, road building, habitat alteration for grazing, global warming.

Scaled quail

Appearance: about 10 inches long with a 14-inch wingspan. Living space: dry grasslands, scrub cactus and low woods. Range: Arizona, New Mexico, Texas, southern Colorado and northern Mexico. Population: about 600,000 in North America, declining 0.5 percent to 4.7 percent annually. Threats: fire suppression, overgrazing, subdividing of rural grasslands.

Bell’s vireo

Appearance: about 4.7 inches long with a 7-inch wingspan. Living space: streamside vegetation. Range: Arizona, Southern California, New Mexico, Texas, northern Mexico and the Midwest. Population: about 1.5 million, dropping 2.7 percent annually. Threats: habitat loss from development, global warming, flood control, invasive plants and uncontrolled grazing.

whom to call

* Buenos Aires National Wildlife Refuge, Friday: Bonnie Swarbrick, 520-823-4251, Ext. 108.

* Avra Valley, Saturday: Mary Lou Cole, 578-0114.

* Nogales, Saturday: Michael Bissontz, 577-8778.

* Catalina Mountains, Saturday: Bob Bates, 296-5629.

* Tucson Valley, Sunday: Larry Liese, 743-3520.

* Green Valley/Madera Canyon, Dec. 28, Reid Freeman, 625-9895.

Gilded flicker

Appearance: about 11 inches long with 18-inch wingspan. Living space: mature saguaro cacti. Range: mainly Southern Arizona and northern Sonora. Population: about 1.2 million, declining 1.1 percent to 3.3 percent annually. Threats: clearing of Sonoran Desert habitat for subdivisions and buffelgrass invasions.

* Contact reporter Tony Davis at 806-7746 or tdavis@azstarnet.com.

Originally published by TONY DAVIS, ARIZONA DAILY STAR.

(c) 2007 Arizona Daily Star. Provided by ProQuest Information and Learning. All rights Reserved.