Caterpillars on the march

Southwestern tent caterpillars (Malacosoma incurvum) are maturing and dropping out of the trees along the San Pedro River, providing a boon for northbound migrants. As Tom likes to say, these fuzzy eating machines are nature's way of turning cottonwood leaves into warblers. As unpleasant as it can be to have creepy crawlers and their poop raining down on you on a bird walk, it's peculiarly satisfying to watch a tiny Wilson's Warbler slamming a python-sized caterpillar against the ground to subdue and tenderize it before squishing out the good parts like toothpaste from a fur-covered tube.

Not everyone is as appreciative of southwestern tent caterpillars as we and the migrating birds are, though. When they emerge in spring and start stripping the cottonwoods and willows of their tender new leaves, some people freak out. We've gotten panicked calls asking why someone isn't doing something to halt the destruction before the caterpillars kill the trees. Well, the trees are in danger, but it's not from the caterpillars. The defoliation happens every spring, and healthy trees can recover quickly once the cats stop eating and go into the pupal stage. Stressed trees whose water supply is being sapped away may not be able to recover, though, and the annual caterpillar invasion may push more and more trees beyond the point of no return as more and more residential wells drain the aquifers that feed the San Pedro River. —SW

P-Dogs are in da howz!

A little good news amongst the grim:

Decades after federal programs extirpated them from the grasslands of southeastern Arizona, Black-tailed Prairie Dogs have returned to their historic home with a little help from their friends in the Arizona Game & Fish Department and Bureau of Land Management.

According to the AGFD press release, 74 BTPDs captured at Ted Turner's Ladder Ranch in New Mexico were released on Las Cienegas National Conservation Area on October 7. It's ironic that the transplants came from over 200 miles away when a small BTPD town persists less than 40 miles from the release site just across the Mexican border from Coronado National Memorial (thanks to a friendly rancher), and the largest remaining colony of this species in the world is less than 150 miles away in northwestern Chihuahua (where the PD photo above was taken).

P-dogs aren't canines, of course, but rodents in the same family as fluffy-tailed feeder raiders. Their sharp alarm calls, actually a complex and adaptable language that transmits detailed information about goings-on in their community, earned them the name that, given Euro-American culinary taboos against dining on dogs, probably saved them from becoming favorite targets of hungry pioneers and greedy market hunters.

They would have been an abundant food source, too. Two hundred years ago, BTPD "towns" numbering in the thousands to millions of inhabitants were found from Texas to Montana. The intensely social nature that inspired wonder in early explorers such as Lewis and Clark (who sent a live specimen back to President Thomas Jefferson) doomed them when cattle replaced the great herds of bison, pronghorns, and elk. In the late nineteenth century, newly-minted cattle barons who saw the colonial rodents as competitors taking food out of the mouths of their stock persuaded the government to launch a campaign of extermination that persists to this day. In their heyday, the shooting and poisoning efforts resulted in mountains of dead PDs displayed as trophies.

This wanton destruction was a disaster not only for the dogs themselves but for entire grassland ecosystems. Prairie dogs are keystone species, altering their habitat in ways that benefit other animals such as Ferruginous Hawk, Mountain Plover, Burrowing Owl, Pronghorn, American Bison, the critically endangered Black-footed Ferret, Kit and Swift foxes, and over a hundred more common species. The p-dogs' range management activities include suppressing woody vegetation, cultivating tasty and nutritious forbs, recycling nutrients from their underground latrines, and providing protected nest and den sites in landscapes where shelter is normally scarce. The dogs' elaborate burrow systems also significantly enhance recharge of aquifers essential for irrigated agriculture and other human activities.

Their underdog status is just one factor that earned prairie dogs a special place in our hearts. Thirty years ago, as director of the Fort Worth Nature Center and Refuge in Texas, Tom (who really ought to be writing this post) launched a project that successfully introduced Black-tailed Prairie Dogs to the refuge's large bison enclosure. Actually, he tried to introduce them to a large fallow pasture adjacent to the "buffalo range," but the p-dogs had other ideas. Like characters in some prison break movie, they dug under the sunken fencing of their temporary pen, crossed the road, and made themselves at home right in the middle of the bisons' favorite grazing area. Over the next few years the dogs became a favorite attraction with the public as well as one of Tom's passions. Their behavior and ecology are complex, fascinating, and easily observed, not to mention that they're civilized creatures that don't emerge from their burrows until well after sunup or stay out past sundown.

This history with prairie dogs prompted us to attend a public meeting held several years ago by AGFD to explore the possibility of reintroducing BTPDs into southeastern Arizona. The opposition was out in full force, repeating the same kind of easily debunked myths you hear at wolf meetings. (So cows and horses break their legs in prairie dog burrows? Have you ever personally seen this happen? No? Then maybe you can tell us why the early explorers didn't report herds of bison limping across the plains?) Naturally, Tom and I stood up for PDs at that meeting, but given the controversial nature of the subject and the glacial speed at which government bureaucracies move, we didn't expect to see any meaningful progress for a decade or more. The announcement of preparations for this week's reintroduction came as a thrilling surprise, and I wish we had been able to donate a few volunteer hours to the effort.

So what do we have to look forward to as BTPDs establish themselves in their new digs? Birders will delight as Ferruginous and Red-tailed hawks and Golden Eagles cruise the colony trying to pick off unwary residents, Burrowing Owls move into abandoned burrows, and longspurs and Mountain Plovers spend the winter foraging in the town's wide open spaces. Children on school field trips will learn about the social life, ecology, and history of prairie dogs, and both residents and tourists who would never have thought to visit Las Cienegas National Conservation Area will stop in for a peek at these remarkable mammals. If left alone, the town could get big enough to support Black-footed Ferrets, perhaps even some raised right here in Arizona at the Phoenix Zoo. A few ignorant people will complain (loudly), but with positive feedback to AGFD and BLM from birders and other enlightened members of the public, these agencies may have the support they need to expand reintroduction efforts to the Sulphur Springs and San Pedro valleys.

In 1968, Audubon magazine published an article titled "Dark Days in Dog Town" about the federal poisoning program. Here's hoping that those days are over and a brighter, more rational day is dawning in our relationship with prairie dogs. --SW

Resources:

Black-tailed prairie dogs return to historical site in Arizona

The Role of Prairie Dogs as a Keystone Species: Response to Stapp

Black-footed Ferrets Return to Mexico

Wired: Rodents' Talk Isn't Just "Cheep"

Arizona Daily Star: Can we talk? Prairie dogs do

More resources

Even more resources

Treasures of the Sierra Madre: Las Guacamayas

One of the advantages to living on the Mexican border is that we occasionally get to cross it. Our latest favorite destination is Madera, Chihuahua, home of the world's largest remaining flock of endangered Thick-billed Parrots.I first visited Madera in September 2002 at the invitation of colleague Noel Snyder, who was a major player in the ultimately unsuccessful attempt to reintroduce the species into Arizona. When I got home, Tom asked, "So, how was the trip?" I replied by showing him dozens of photos of parrots, nesting Eared Quetzals, and much more. His next words, once he caught his breath, were, "When do we leave?" Two weeks later we were back in Madera and already planning tours through SABO with the parrots and Eared Quetzals ("Ps & Qs") as the headliners.

One of our traveling companions on last July's tour was conservation biologist, author, and Princeton University professor David S. Wilcove (fourth from the right in the photo at left). David's encounters with the guacamayas, as Aldo Leopold called them, inspired him to write a thoughful article on the species' past, present, and future for the Winter 2008 issue of the Cornell Lab of Ornithology's magazine, Living Bird.

The best news in this article for the parrots and those of us who love them is that the American Bird Conservancy and ProNatura have been hard at work negotiating protection for their most important nesting areas. With on-the-ground conservation efforts and the added economic incentives of ecotourism, there may hope for the future of these gaudy, raucous treasures of the Sierra Madre. --SW

Border Fence Boondoggle

There's breaking news on the southeastern Arizona section of the international border fence. Yesterday afternoon U.S. District Court Judge Ellen Segal Huvelle temporarily halted work already in progress on the part of the fence that passes through the San Pedro Riparian National Conservation Area. The judge based her ruling in part on the unprecedented speed with which the federal agencies had rushed the approval through to allow construction to begin "before anyone would wake up."

The Sierra Club and Defenders of Wildlife filed the suit over the San Pedro portion of the fence out of concern that the barrier will alter the river's natural drainage patterns, increase erosion, destroy riparian vegetation, and disrupt archaeological sites. As designed, the San Pedro portion of the barrier would simply funnel foot traffic from the surrounding desert through the fragile riparian zone, magnifying its impact on the landscape and wildlife. The Bureau of Land Management's own assessment acknowledged these issues, yet the agency issued a permit to the Department of Homeland Security without a full environmental assessment or opportunities for public comment.

Birders have a more vested interest than many Americans in this particular border issue. The 700 miles of double-layered fence mandated by Congress and President Bush would cut a wide swath through the Lower Rio Grande Valley and southeastern Arizona, two of North America's top birding destinations. This contentious barrier would run through some of our most scenic and biologically diverse wildlife habitats, including national monuments, wildlife refuges, and forests, state parks, wilderness areas, and other public lands. We'll be laying waste to tens of thousands of acres of American soil, most of it wilderness. Migration corridors for earth-bound wildlife such as jaguars, ocelots, coatis, pronghorns, and desert bighorn sheep would be blocked. People, on the other hand, will readily find ways over, under, around, and through the fence, as they already do at our existing border barriers.

Many experts on national security, economics, and the environment believe that this border fence is a wretched, misbegotten boondoggle that's not going to protect us from terrorists and is little more than a finger in the dike to hold back immigration. Even those who don't give two hoots about wildlife and wilderness question the economics. The Department of Homeland Security estimates that the final construction cost of the 14-mile fence at San Diego will be $129 million, or $9 million per mile [source]. Multiply this times 700 to 1950 miles of our southern border, and you get $6.3 to $17.6 billion out of our pockets. And that's not counting monitoring and maintenance into perpetuity. Is our economy so healthy and immigration such a dire threat that we can divert enormous amounts of money from programs that provide for the needs of our own citizens?

There's no doubt that we have to do something about illegal immigration. Its impact on our economy and health care system may be debatable, but there's no doubt that it's damaging public lands and wildlife habitat along the Mexican border. But ruining tens of thousands of acres of our own lands and straining our own struggling economy in a vain attempt to halt it amounts to cutting off our own nose to spite the illegal immigrants' faces. And I won't even get into the message it sends to our neighbors and the world.

The 10-day reprieve granted by Judge Huvelle is a small victory for American taxpayers, our public lands, Arizona's wildlife and habitats, and the birding community, but the battle for a sane, environmentally responsible approach to border security is far from over. Judge Huvelle's decision could be overturned by Homeland Security Secretary Michael Chertoff, who has been granted authority to waive any and all environmental laws to build the border fence.

If this one small part of the fence can be halted temporarily, there's a chance that the whole project can be delayed long enough for the country to come to its senses. Our precious borderlands and their wildlife need your support. Please call and/or write your representatives in Congress to let them know that you support a more environmentally responsible approach to controlling immigration. --SW

RAIN!

Last night it rained. Lightning strobed, drops spattered dusty windows, and Tom and I watched as the numbers crept upward on the electronic gauge mounted by the front door. It topped out at 0.12", twelve hundredths of an inch - barely enough to refill the small rain barrel, but we were grateful for every drop.

If you don't live in Arizona, the profound importance of this may elude you. We're in the grip of a devastating decade-long drought, and this is the first time since October that we've been able to measure and record rainfall in our yard in Bisbee. That's right - almost four months without measurable precipitation. Any green thing in our yard that doesn't have its own dripper line is in mortal peril. Even the prickly pear cacti are shriveled and limp. Last night's micro-storm would have been disappointing had we not been waiting so long, had the situation not been so dire. Instead, we celebrated. Standing outside in a February rain might not seem too wise, but it had been just too damned long since I'd felt drops of water on my face that didn't originate from a showerhead.

Living in the desert can and should change your view of the world and its resources, but too often it doesn't. Oblivious humans keep living like there was no tomorrow, building enormous houses, putting in lawns, swimming pools, and golf courses, using hoses instead of brooms on dusty driveways, and holding car washes to fund high school field trips. To sustain the unsustainable, vampire wells overtax fragile and finite aquifers, changing desert streams from ecosystems into drainage ditches.

I'm afraid that for the Arizona I love there really is no tomorrow. I wonder if a decade or two of devastating drought is what we need to motivate that change in world view, or at least to slow the rate of destruction, but this is just too horrible to contemplate. It's been hard enough already, especially watching birds more familiar to me than my human neighbors disappear from their haunts, their empty territories as mute and forlorn as abandoned houses. Rain can't wash away the devastation, but it can ease the burdens of those who have survived (for now). So let it rain...please. --SW