Updated Mar 17, 2013 - 8:20 am
Tucson's artificial lakes are magnets for birds
TUCSON -- On a sunny, cool morning recently on Tucson's far northeast side, a Say's phoebe, complete with a light-orange breast and a gray back, stood atop an orange metal fence.
A pied-billed grebe, with a black stripe on its bill, crossed a patch of lawn near a huge artificial lake. American wigeons pecked at the grass for food. In grasslands not far away, rufous-winged sparrows, shy, elusive birds that are seen only in Southern Arizona in this country, darted through desert broom, mesquite trees and native grasses. A great egret stood by a second pond a mile away.
Perhaps surprisingly, urban Tucson draws even more bird species than some of Southern Arizona's famous, more remote birding attractions such as Madera Canyon and the San Pedro River, according to species counts reported by the website eBird.org.
The birds in the scene above were spotted at The Lakes at Castle Rock, an upscale, gated subdivision near Tanque Verde Road and Catalina Highway where 14 lakes sit side by side with large stands of non-native grasses and desert plants. There, more than 150 bird species have been seen over 30 years, says the ebird site, which is run by the Cornell Laboratory of Ornithology and the National Audubon Society.
When The Lakes at Castle Rock was developed 31 years ago, it was synonymous with controversy. Public outrage erupted over the presence of artificial lakes in a desert city with limited water supplies. That led to a 1987 state law banning new artificial lakes within areas such as Tucson that have state-run groundwater management areas - meaning there will be no more such developments here.
But today, Castle Rock is one of many artificial-lake areas of Tucson that have drawn well over 100 bird species, eBird records show. A broader area surrounding Castle Rock, covering about four square miles, has drawn 240 species, said Brian Nicholas, an expert birder who lives at Castle Rock. Belted kingfishers, black phoebes and vermillion flycatchers - all lovers of riparian habitat - have been drawn to the lakes along with many other duck species.
Specifically, here's how Tucson stacks up against other Southern Arizona birding hot spots:
—In the Tucson metro area, about 345 species have been recorded on eBird at 41 hot spots.
—At Madera Canyon, more than 265 species have been recorded at 15 hot spots.
—Along the Upper San Pedro River, 295 species have been recorded on eBird at nine hot spots.
—In the Patagonia area, home of a lake-based state park and a Nature Conservancy preserve along Sonoita Creek, 351 species have been recorded at seven hot spots.
—In Cave Creek and the Portal area near the New Mexico border, 304 species have been recorded at 15 hot spots.
—On Mount Lemmon, 216 species have been recorded at 25 hot spots.
—In the Huachuca Mountains and neighboring Fort Huachuca, 277 species have been recorded at 17 hot spots.
Tucson's variety of bird species is in part a tribute to the power of artificial waters. About 285 species have been drawn to the ponds, muddy edges, marsh grasses, trees and desert shrubs at Sweetwater Wetlands near Prince Road and Interstate 10, which is run by Tucson Water and treats wastewater.
City and county lake-based parks such as Reid, Kennedy, Aqua Caliente, Columbus and Lakeside have drawn 174 to 230 species, eBird shows.
Other major bird sources are the lower-density suburban subdivisions whose homes lie on lots of three acres and up. Some of their owners have ponds. Many are planted with native and non-native trees and shrubs. Their lands are often crisscrossed by tree-lined desert washes - bird magnets.
Tucson Audubon Society officials, who promote conservation, take pains to say that just because the city draws so many urban birds doesn't mean we should pave over all the desert. It's important to keep natural areas wild, in part to draw birds that like native desert, they say.
But using water in some fashion to draw birds is worth it, said Jennie MacFarland, an Audubon Society conservation biologist, although she's not promoting artificial lakes.
"When you have lakes, it's a trade-off, because it provides habitat for some species at the cost of others, through habitat destruction caused by groundwater pumping," MacFarland said. "You just have to irrigate vegetation useful for wildlife. It gets people exposed to birds and caring about birds."
A wide range of habitats is also why the Tucson area finished first last Christmas among all areas in the state in the annual Christmas Bird Count, with 153 species. Besides low-density areas of the Catalina and Tucson Mountain foothills, other areas such as the Santa Cruz River, desert canyons such as Finger Rock and the washes of suburban Oro Valley also helped build the count, said Rich Hoyer, who coordinated last year's Tucson Christmas count for the National Audubon Society.
One more reason for our large urban bird count is that many people are around to spot the species, said Mark Stevenson, an expert Tucson urban birder.
He also points out that many or most of the species that draw out-of-state birders to Southern Arizona can't be found in the city very often or at all. They include the zone-tailed hawk, sandhill crane, Bendire's thrasher, painted redstart, hepatic tanager, thick-billed kingbird and red-faced warbler.
"If I had to spend a day in May birding and the choices were between Reid Park and Madera Canyon, I would go to Madera without a doubt," Stevenson said. "My list might include fewer species ... but they would be more 'special' than what I might find in a city park habitat."