The Long Reach of Tiny Birds

Hummingbirds are inspiring new cross-border conservation efforts between Mexico and the United States

• Tim Vanderpool
• Oct 01, 2002

SUNLIGHT escapes the thicket, pausing on a furious flash of red and green that careens through the damp morning air. "Oh, there's that rufous again," Marion Paton whispers to visitors, with a conspiratorial grin.

The rufous hummingbird ignores the nosy humans charting its dips and dives from a hushed corner of Paton's overgrown backyard. Instead, the bird's fierce black eyes focus on a feeder, one in a row of nine, all glistening like the dessert tray in a busy roadside diner.

"He's a hungry one, for sure," says Paton, a retired school-cafeteria manager who runs her Hummingbird Haven on two-and-a-half acres ringed by thick forest. A true hummer's Xanadu, the feeding station is situated in the tiny town of Patagonia, Arizona, amid verdant mountains some 20 miles north of Mexico.

 
Photo: © WALLY PATON
HAVEN'S REWARDS: Marion Paton (above) poses with one of many feeders at her Hummingbird Haven in Patagonia, Arizona. Southeastern Arizona is a hub for the tiny, hovering birds, with as many as 15 different species frequenting Paton's backyard. Among the visitors are the broad-billed, the rufous and the magnificent.

When migration is heaviest in spring and fall, this region becomes one of the most species-rich hummingbird hubs in North America. As many as 15 different kinds of hummingbirds visit Paton's lush oasis, from the irascible rufous to the broad-billed, racing by in a flurry of shimmering blues and greens. A few of these birds stick around during much of the year. But most others are just passing through for breeding season or a quick meal. "These birds really get to be family," Paton says, "and I love seeing them show up year after year."

But each year that journey becomes more treacherous for tens of thousands of these minute fliers, as crucial migration corridors are squeezed by urban development or degraded by heavy cattle grazing, which drives out many native plants on which the hummingbirds rely. Despite these threats, Paton says she hasn't seen hummingbird numbers dropping at her backyard rest stop--at least not yet. To ensure that never happens, a growing network of researchers and activists are now reaching across borders, cooperating on everything from habitat preservation and ecotourism to public education in Mexico.

Part of the problem of protecting hummingbirds is biological. Driven by notoriously raging metabolisms, these creatures rely on abundant flowering plants--spiced by insect appetizers--for constant meals. When flowers get scarce, fearsome territorial instincts take charge, says Bill Calder, a University of Arizona hummingbird expert and member of a research project sponsored by the Arizona-Sonora Desert Museum in Tucson. "We had a situation where one male rufous was guarding the only chuparosa plant, the only patch with any flowers," says Calder. "He was fiercely defending it. When the other hummingbirds were gone, he'd plop down on the ground exhausted."

You can see why backyard feeders might be a hungry hummer's Nirvana. "I go through six quarts of sugar water a day," says Paton. "They stop here to fatten up on their way south. Then we see them come back in March. It's like running a boarding house."

Author David Lazaroff puts this phenomenon in perspective. "Being a hummingbird is like driving a car with a one-gallon gas tank: There is an almost constant need to refuel," he writes in The Secret Lives of Hummingbirds.

The availability of food--whether from feeders, or the flowering chuparosa, morning glory and ocotillo--helps determine which migratory routes the birds choose. It also rules their short, furious lives.

You'd have a hearty appetite too, if you shared a hummingbird's vital stats. For example, it boasts the most rapid heartbeat for a bird--nearly 500 beats per minute while resting, and 1,260 beats when in action. It weighs the equivalent of only a few dimes at most, but flight muscles account for nearly 30 percent of its total body weight. It also boasts the most rapid wing beats of any bird, as many as 80 beats per second, and goes into 60-mile-per-hour dives.

This high-octane lifestyle compels it to sip as much as one-and-a-half times its body weight in nectar daily. It also requires finely tuned travel skills; those hummingbirds passing through Paton's sanctuary must remember where to find the next lunch stop.

"It's really tantalizing to wonder how this little brain that weighs 200-odd milligrams can program all this stuff in there," Calder says. For hummingbirds, long-distance travel also requires pinpoint logistics. "If they put on maximum fat, they can cover 500 or more miles at a stretch," he says. "But according to all the notes I've collected, you don't see the high end of their weight range on northbound migration. This makes sense--if they put on a lot of fat, enough to go too far, they might overshoot the next filling station. It's sort of like when I'm going north over mountains, I don't try to have a full tank. Why, when I know there's a gas station on other side?

"The other problem is," Calder says, "if you have enough gas in your tank to go 200 miles north into winter where there are no flowers, then what do you do? If there's not a filling station there, you're screwed. Somehow, hummingbirds are factoring in these things."

 
Photo: © SID AND SHIRLEY RUCKER (DRK)
LIFE LINES: Tens of thousands of hummingbirds travel regularly between Mexico and the United States, often along verdant pathways such as the San Pedro River. But this and other crucial migratory corridors are threatened by development and agriculture. Conservationists are working on both sides of the border to educate citizens on the importance of these pathways, so that birds like these broad-tailed hummingbirds (above) will continue to have natural alternatives to plastic feeders.

Their timing must also be precise. "In a lot of situations, because of a long migration or because they're up high where spring doesn't come very early, they've got about a ten-week period in which to create nesting sites and breed," Calder says. So for some species, he adds, "there's not enough time to do it twice in one season."

Want another complication? Try this: Females usually lay only two eggs per clutch, and as many as half of all chicks may die. Also, the females of some species, such as the broad-tailed, may live only two years. So a female's lifetime reproduction may be only two eggs, Calder says. "If anything else drops their population down--something in the weather or dealt by the hand of man--they don't have hope of building back up again."

All of which adds up to one big challenge for conservationists such as Calder, Tom Van Devender and their colleagues on the desert museum team. The biologists travel with Mexican colleagues throughout the state of Sonora conducting pollinator research on hummingbirds and nectar-feeding bats. They also chart migration paths as far as 300 miles south of the border, as well as visit rural schools to hand out feeders and teach children about hummingbirds.

"For a lot of these kids, it's the first time they've seen a slide show, the first time they've had any natural history materials at all," says Van Devender. "And the hummingbird feeders are magic."

A Mexican team member calls the response "outstanding." "Students, teachers and parents have eagerly participated with their reports and stories, with hummingbird feeder maintenance and observations," says Eduardo Gomez, an independent researcher based in Sonora. "Maybe it's the beauty of seeing these birds at close range--watching with attention something they had seen all their lives without really looking."

Since ecosystems don't stop at national boundaries, sharing information and expertise between Mexican and American biologists makes sense, Gomez says. "There are rivers that run along the border for both countries. Others start in one country and flow to the neighbor's territory. Still others start in one country and then enter the other, only to return again to their place of origin."

These rivers are vital to migrating hummingbirds--and vice versa. "As they travel along these corridors, the birds feed from flowers," he says. "So they serve as migratory pollinators, effectively helping the reproduction of plants in a mutually beneficial interaction."

Unfortunately, the Mexican waterways have long been treated like poor cousins to their American counterparts. Gomez calls the San Pedro River a case in point: Starting in northwestern Mexico and flowing northward, its protection has finally become a pressing international concern.

In Arizona, where burgeoning communities along the river threaten to run it dry, activists have poured money and time into saving what has become the San Pedro Riparian National Conservation Area. Considered a natural gem and a hotbed of hummers, this 58,000-acre federal parcel on the Mexican border is home to more than 470 species of birds, mammals and reptiles.

The same dedication and funding is needed to protect the San Pedro in Mexico, where Gomez says there's "an evident impact on its habitat. The condition of its riparian woodland can be summarized in one word: fragmented. Also, rural communities are located very close to the river, and that has led to garbage being scattered near its margins. There are also some problems with sewage disposal."

Luckily, Mexican ecologists can draw on reams of San Pedro data already compiled to the north. "Many successful studies on avian and woodland conservation have been done in Arizona, including practical strategies on water conservation, native plants reforestation, bird surveys, public outreach and land management," Gomez says. "Sonora, for its part, has only recently started to study its part and begin planning to implement strategic conservation actions."



 
Photo: © JOHN CANCALOSI (DRK)
SMALL WONDERS: Measuring only a few inches long and weighing less than a few coins, hummingbirds are still powerhouses. They can beat their wings as fast as 80 times per second and cover 500 miles or more on a single stretch of their migratory journeys. To fuel this activity, the creatures must ingest copious quantities of nectar daily. Although Anna's (above) and other hummingbirds require little real estate for their spiderweb-and-lichen nests, some females produce only a few eggs in a lifetime.

Meanwhile, yet another strategy is at work near Mexico's San Pedro. Through their Corredor Colibrí Project (Spanish for "Hummingbird Corridor") conservationists Juan Caicedo and Jennie Duberstein are planning a series of pollinator gardens through this rugged region laced by tree-lined streams and small mountain ranges.

They're also presenting economic alternatives to destructive agricultural practices, such as over-grazing. Caicedo saw a glaring need for action while here researching his senior thesis for Prescott College. "Including drainages, there are about 40 miles of the San Pedro River on this side, and they haven't gotten the attention they deserve," Caicedo says.

Despite a shoestring budget and no institutional support, they've already helped develop school wildlife programs, a budding wetland near municipal wastewater ponds in the border town of Agua Prieta and ecotourism that encourages ranchers to protect riverside areas by carefully managing their cattle. This growing tourist trade on the Mexican side of the border is likewise a boon to area residents, who serve meals to visitors.

The birding tours are conducted by the Southeastern Arizona Bird Observatory (SABO), a conservation education group based in Bisbee, Arizona. The outings build awareness among visitors and provide residents with incentives for good conservation, says Sheri Williamson, author of Hummingbirds of North America and a SABO naturalist. "Just across the border is a land of tremendous poverty, where dollars brought in by tourists can make a huge difference. And the one tourist resource that these communities offer is migrating birds.

"Rural communities on either side of the border are stewards for these resources," she says. "If we can find economic incentives for better stewardship of these resources, then we all win."

Back in Patagonia, Marion Paton already claims a victory of sorts: Every day still brings a new palette of colors to her backyard, where she's now watching the breakfast rush finally ebb. Shadows shrink as the sun steadily climbs. Still, lunch is mere minutes away for these voracious diners.

"Hummingbirds should be protected," Paton says firmly, "not just for me, but for people who come here from all over the world to see them. These are such small, beautiful and delicate creatures."

Almost on cue, the brazen rufous buzzes past. Delicate maybe, he seems to say, but also extremely determined to survive. Fortunately, he has many equally committed fans in this hummingbird-rich region, where dull lines on a map just can't compete with brilliant flashes of orange, green and blue.

Political boundaries mean nothing to creatures such as the white-eared hummingbird, the monarch butterfly or the green sea turtle, which all travel regularly between Mexico and the United States. Recognizing that North America is one continuous habitat, the National Wildlife Federation recently launched a new program in Mexico, Alianza para la Vida Silvestre (Partnership for Wildlife). The partnership grew out of requests from Mexican organizations hoping to adapt NWF's materials and approach in their country. NWF and its partners will educate children and adults, and help Mexican citizens play an enhanced role in environmental policy-making. The ultimate goal of the new program is to help build a broad base of support for conservation in Mexico.