by Terry Masear
Watching the platinum-colored sisters snapping up fruit flies in the aviary that sunny afternoon in April, an image of the dark ice cubes they had been when they arrived in the teacup comes back to me. It seems impossible these robust beauties can be the same birds that arrived frozen and near death two months earlier. Rather than applauding myself, I am impressed with the resilience of nature in the face of so much human error and interference. Now, despite their unpromising beginning, the brown-sugar twins are about to return to the wild, where they will thrive and perpetuate their extraordinarily attractive genetic heritage into the foreseeable future.
After checking the feeders in the flight cages on the patio, I head back to the garage. As I pass Gabriel’s cage, I notice him running his bill up and down his wing feathers, a clear sign that a hummingbird is feeling relaxed. I hurry into the garage, go down the assembly line of gaping mouths in the ICU, then return to examine Gabriel. When I step outside, I can see Gabriel on his low perch resting quietly in the sun. But his feathers still appear black.
“Damn,” I whisper under my breath as I approach him. “That’s some serious road grime. We’ll have to bathe you again.” But when I lift his cage, I see Gabriel’s deep green feathers and brilliant magenta gorget flash brightly in the sunlight. “Ah, you’re an Anna’s. But you’re so dark,” I observe. And then I notice something else.
Surprised and confused, I grab my cell phone, which is attached to me day and night during hummingbird season, like a fifth appendage, and call Jean. When she answers on the eighth ring, I don’t waste any time.
“Have you seen a lot of those cobalt-green Anna’s like the one I brought you during that rainstorm four years ago?” I ask her.
“Not a lot.” She pauses reflectively. “Just a couple every year.”
“How about hummingbirds with white spots on their heads? How many of those have you seen?”
Jean thinks for a moment. “Just that one.”
“Are you sure?”
“Uh-huh,” Jean says in a strained voice that indicates she’s lifting something far too heavy.
“Are you absolutely sure?”
“Yeah, I’m sure,” she answers impatiently. “Why?”
“Because he’s sitting in a cage on my patio.”
CHAPTER 13
Hello Stranger
IT’S WHAT YOU LEARN once you think you know everything that makes all the difference. After working closely with hummingbirds for two years, I imagined I understood them pretty well. But in this naive assumption, I was a lot like a college student who comes home for winter break her freshman year spouting a world of new ideas without understanding the true meaning behind any of them.
“The magenta has come in on his crown and gorget but he still has a white spot on his head. Do you think it’s the same bird I brought you as a nestling four years ago?” I ask Jean excitedly as I crouch beside the cage admiring Gabriel’s cobalt-green feathers and bright white spot glistening in the sunlight.
“No,” Jean answers flatly. “I know it is.”
“Really? You think he flew all the way back up here after you released him?”
“Well, let’s see.” Jean speculates. “If he flew north in a straight line, it would take him all of about thirty minutes to get to Beverly Hills.”
“Doesn’t that kind of shock you, though? That after I rescued him from that rainstorm he would end up back here four years later under the same circumstances?”
“Nothing they do shocks me anymore.”
“But why here? I mean, of course, for a lot of people, Beverly Hills tops the list of desirable places to live, but why would he come here when he could go anywhere he wants?” I wonder, envisioning the appealing landscape and picturesque small towns sprinkled up and down the rugged and spectacular California coast.
“Because they return to their birthplace to breed,” Jean points out, as if explaining something obvious to a slow child.
“But he was just a baby when I brought him to you. How does he know where he was born?”
“Don’t have a clue,” Jean replies, “but obviously he does or he wouldn’t be there.”
Although I have read about the remarkable homing abilities displayed by other birds, I never thought Los Angeles hummingbirds would be so driven to return to a specific location in such a tangled urban sprawl. In a city crammed with a million houses and apartment buildings that appear as an endless mosaic when you’re flying over in a jumbo jet, how can hummingbirds determine which neighborhood and in some cases, even more unbelievably, which particular yard to stop at?
Anecdotal accounts of hummingbirds returning to their birthplaces to breed have been around forever. But it wasn’t until avian aficionados began banding hummingbirds thirty years ago that these stories got the weight of solid scientific evidence behind them. Since then, banding groups have reported almost unimaginable discoveries from their investigations. Among other amazing things, banding studies have revealed the astonishing migratory flights some of these micro-marvels undertake annually.
While many Los Angeles hummingbirds don’t go anywhere anymore, and their most demanding flights are between sugar feeders on the block, others make the trip to Mexico and back each year. George C. West, a professor emeritus of zoophysiology at the University of Alaska, banded over fourteen thousand hummingbirds in Arizona during a decade spent tracking the migratory habits of the fifteen western species. Professor West cites research by the North American Breeding Bird Survey estimating the global population of Anna’s hummingbirds at five million. Ninety-six percent of Anna’s breed in the United States, and 15 percent spend their winters in Mexico. Black-chinned hummingbirds are also estimated at five million, with 86 percent breeding in the United States and 100 percent wintering in Mexico.
According to Professor West, each autumn large numbers of Southern California Anna’s and black-chinned migrate east to Arizona’s sky islands—high-elevation forests surrounded by low-elevation desert—before continuing south into northern Mexico for the winter. In the spring, these birds complete their circular migration route by returning to California west of the sky islands at lower elevations that host a sufficient supply of edible insects. In addition to the large sedentary population of Anna’s living in Southern California, millions of others nest up and down the West Coast. Some migrate as far north as British Columbia and more recently Alaska, where they have extended their distribution over the past few decades thanks to abundant sugar feeders and introduced vegetation.
Impressive as these international flights may seem for a bird that weighs less than a pygmy mouse, hummingbirds from other parts of the United States complete long-distance migratory journeys that border on the supernatural. Ruby-throated hummingbirds migrating north to Canada to breed and nest fly five thousand miles a year on a journey that includes a nonstop eighteen-hour, five-hundred-mile flight over the Gulf of Mexico each spring and autumn. Not all of the estimated seventeen million ruby-throated hummingbirds that breed in the United States make this trans-Gulf flight—some prefer to follow the coastline—but the intrepid voyagers that do double their weight, from three grams to six, before departing land. Hummingbirds preparing for this strenuous crossing sometimes put on so much weight, they lose their capacity to fly for a short time. Every September, callers from Alabama and Florida report finding the squishy butterballs splayed on the ground under sugar feeders, waiting up to thirty minutes to burn off enough weight so they can get airborne again.
Researchers believe the ruby-throated travelers depart land at dusk and make most of their trans-Gulf journey at night. Lying in bed on cool September nights, I try to imagine these miniature marvels gliding through the silent darkness, spinning over an opaque ocean with nothing but the moon and stars to guide them on their overnight flight. They are propelled by forces beyond themselves, across five hundred miles of flat and featureless water, with no room for error. Since hummingbirds fly low when they migrate, fishermen occasionally report seeing them wh
iz by in the early-morning hours. Some seek a temporary resting place and have been spotted perched on the masts of boats in the Gulf hundreds of miles offshore. Although it’s assumed most hummingbirds make this flight straight through or perish if they fall into the ocean, we can’t be certain.
In Southern California we get dozens of calls every year reporting hummingbirds floating around in swimming pools. Most of these downed drifters are new fledglings that have fallen into the pool and do not have enough strength to fly out. But on several occasions, people have called about an adult hummingbird floating in the pool only to discover five minutes later that the bird has flown off.
The legendary trans-Gulf flights made by waves of ruby-throated hummingbirds are the stuff dreams are made of. But other marathon fliers like the rufous are capable of completing a seven-thousand-mile round trip when migrating from Central America and the U.S. Gulf Coast to Alaska and back. As reported in Bob and Martha Sargent’s quarterly research journal NetLines, a female rufous banded in January of 2010 in Tallahassee, Florida, was recaptured in Alaska’s Prince William Sound in June of the same year after completing a 3,500-mile flight. Six months old when banded, as determined by the diagonal grooving on her bill, the young rufous weighed in at 3.7 grams. Banding researchers speculate the year-old female had been born in Alaska in June of 2009 and was returning to her birthplace to breed, clocking 7,000 miles her first year out. Such phenomenal migratory feats make Gabriel’s thirty-minute, twenty-mile commute from Torrance to Beverly Hills appear pretty unremarkable, even if he did have to navigate several formidable skyscrapers on his trek through downtown.
Migratory species like the ruby-throated and rufous spend much of their lives on the road, heading to northern breeding grounds from March to May and returning south from August to October. Rufous hummingbirds that do not elect to make the easy stop in Southern California migrate north up the coast before nesting in forests from the Sierra and Rocky Mountains to south-central Alaska. Rufous remain in their northern habitats only a few months to breed and nest. By August, adult males spearhead the wave back south through the Rocky Mountains and the sky islands, reaching central Mexico in October, where they spend the winter molting their feathers before commencing their long flight north in March. To accomplish these mind-boggling journeys, hummingbirds rely on the wisdom of their genetic history and the information stored in tiny brains the size of silver cupcake beads. Envisioning these near-weightless fliers braving the formidable obstacles posed by wind, fire, rain, and snow to adjust to the seasons of the earth is nothing short of awe-inspiring.
Some hummingbirds suffer what rehabbers refer to as migration fatigue. In early April of 2007, I got a call about a Costa’s that had fallen from the air onto a third-floor balcony at a chiropractic hospital in Los Angeles. According to the two interns who were taking a lunch break there, the adult male dropped out of the sky and landed flat at their feet. When they handed the spectacular, violet-hooded adult to me in a sterile-glove container, he was so listless, I feared he was about to die. But after a few hours of refueling on formula while sitting in a flight cage on the patio in the sun, he exploded to life and soon was buzzing smoothly back and forth between perches. I kept him overnight and by morning he was so energetic that when I opened his cage, he rocketed over the house in less than a second and headed straight east toward the desert.
A few weeks later, when I came out to fill feeders in the aviary at midmorning, I noticed an adult male rufous sitting motionless on a low-hanging sugar feeder I had attached to the underside of the patio umbrella. His eyes were half closed and he appeared exhausted and disheveled, as if he had kept his foot on the accelerator to reach his destination despite running low on fuel. When I reached for him, he didn’t blink, and as I closed my fingers around him, he went limp in my hand. I slid him off the sugar feeder—always slide a hummingbird off a perch; never lift straight up—and placed him on a low wooden perch inside a large flight cage in the sun. We do not band our releases in Los Angeles, but the minute he regained consciousness, I suspected I had rehabbed this rufous when he was young. Adult hummingbirds initially reject the formula we use in rehab because the sugar content is lower than that of the nectar they are accustomed to in the wild. But this weary traveler took to the syringe as if he had been drinking from it all his life and began gulping formula without being coaxed or coerced. More surprising, unlike most uninjured adults, he exhibited no fear or agitation when I examined him in my hand. And rufous males are not known for their relaxed acceptance of the human touch. By midafternoon, the feisty flier had burst back to life, and the next morning expressed a clear desire to get back on the road. After eating an impressive breakfast, he began gliding back and forth between perches impatiently. When I opened his cage twenty minutes later, my rufous revisit shot fifty feet into the air; within two seconds, he had cleared the Pacific Design Center a block away and was heading into the hills north of the city to fulfill his destiny.
Migration fatigue is considered unusual, occurring only in older birds or those that are in some way physically compromised. But the natural and manmade hazards awaiting hummingbirds on their long-distance flights over land and sea are random and limitless. And there is no way to determine how many of these fearless fliers encounter life-threatening bumps in the road during their extended journeys.
Marathon flights are not hummingbirds’ only fantastic migratory achievements. In addition to having a GPS that guides the bird home each spring, each hummingbird possesses an internal clock capable of directing him to the same sugar feeder on the same day, year after year. Same-date recaptures—banded birds captured at or near the same location on the same day in successive years—are surprisingly common. Members of the Bob and Martha Sargent’s Hummingbird Study Group have documented a ruby-throated female banded on August 18, 2009, and recaptured on August 17, 2011, at the same nature center in Nashville, Tennessee; a female rufous banded as an immature bird in Alabama in 2002 and recaptured at the same feeder for nine consecutive years during her spring migration north; and two ruby-throated females that had been banded hours apart on August 11, 2005, recaptured in the same trap on August 11, 2012, at the same location in West Virginia.
Researchers attribute hummingbirds’ ability to return to the same feeders after migrating thousands of miles to their exceptional spatial memory. Migratory hummingbirds can remember to within inches the precise location and height of a sugar feeder they frequented before heading south for the winter. If a feeder hanging on a long wire in the fall is attached to a shorter wire the following spring, a returning hummingbird that has completed a several-thousand-mile journey will initially hover at the lower height the feeder was hanging at six months earlier. Nobody knows how they do this.
Ironically, because of hummingbirds’ precision in spatial memory, when tree trimmers and weekend gardeners in Los Angeles replace cut nests near their original locations, the mothers are often unable, or perhaps unwilling, to return to the nests. One caller who accidentally cut a nest of two-day-old Allen’s twins from a bamboo stand in his yard in Silver Lake reattached the branch a few feet from the original location less than an hour later. Zach called me several times to report the mother flying around unable to locate her nest with the pair of hatchlings. He finally sent me a video showing the nest tucked into the bamboo with the mother buzzing around a few yards away. I called him back and advised him to move the nest to the exact spot at which she was hovering. Since a layer of outer branches had been trimmed off the bamboo, Zach could not get the nest precisely in its original location, but he was able to attach it closely nearby. An hour later, he sent another video that showed the mother searching within a few feet of the nest, which was positioned deeper in the hedge than it originally had been. I instructed Zach to sneak in and feed the hatchlings sugar water every thirty minutes while the mother was conducting her reconnaissance. The distressed female continued to fly off and return dozens of times during her protracted afternoon search.
“I just want to run out there, point to it, and say, ‘Look, it’s right here!’” Zach exclaimed after watching the mother search in vain for three hours.
“If only you could, right?” I agreed.
Finally, as darkness descended and it became clear the naked hatchlings had no chance of surviving the night without their mother’s body heat, I had Zach deliver the twins to rehab.
This scenario plays out several times each year with accidentally cut nests. In the case of young hatchlings, callers often report the mother searching within a few feet of a repositioned nest. Rather than being unable to find it, some nesting females may be wary of sitting on a nest that has been moved to a new location. Interestingly, when the same situation involves nestlings or grounded fledglings that are old enough to cry audibly, the mother quickly falls back into her maternal routine. Even when I have callers place feathered chicks into faux nests in a tree several yards from where they were discovered, the mother easily locates them and resumes her feeding duties, suggesting that hummingbirds rely more on sound than sight when locating their displaced young.
With all of their mysterious abilities, hummingbirds never cease to astonish even the most experienced experts. How do these miniature fliers make such epic journeys year after year in their quest to return to their ancestral birthplace? Zoologists, ornithologists, and natural historians speculate and marvel at hummingbirds’ miraculous capacities from their different scientific perspectives. But perhaps only the imagination of the poet can envision these tiny bundles of contradictions as they navigate their way over arid deserts, sprawling plains, alpine forests, fog-shrouded plateaus, rolling hills, windswept bluffs, snowcapped mountains, wetlands, rivers, lakes, and a vast ocean. Venturing into the unknown each day, moving on to new places or in search of others to which they have already been, hummingbirds live the life of pure adventure as they navigate their way through ever-changing though not entirely unfamiliar surroundings in the natural world.
