There's No Place Like Home!

Juvenile Harpy Eagle. Photo by Mark Watson

Scarlet-horned Manakin. Photo by Mark Watson

There’s nothing quite like a visit to a third world country to make one appreciate the lifestyle Americans take for granted. I currently have a special fondness for certain luxuries: hot water; potable water; meat that is recognizable; well-maintained roads, vehicles with adequate exhaust systems, and uninterrupted sleep. There are positives from the trip that I always will cherish: new and improved friendships, awe for the amazing diversity of flora and fauna of Venezuela; and an greater appreciation for a different culture.

We saw birds too! Many of them! While I didn’t see anything approaching the record 380+ species recorded by the top birder in the group, I tallied a remarkable 328 species, of which 281 were life birds for me. Yes, we did see the magnificent Harpy Eagle, one flighted youngster of 18 months, and both parents. Our Venezuelan guides led us right up to a viewing spot and there was the immature eagle, perched right in plain view. As we watched, the adult male flew over, likely checking to see if all was well with Junior. We later viewed the adult female who perched nicely for viewing through the scope as we were leaving the area.

We were asked to list our “top three” birds by our trip leader, Jim Black of Chupaflor Tours, so the group could determine the “top” bird of the trip. Indeed, the Harpy Eagles were a big score, but it seemed just a little too easy to find them, almost as if we didn’t earn the experience. We also saw rarities, birds that skulked in the dense undergrowth, and a wide variety of brilliantly colored species like the Paradise Tanager that looks as if it were colored by a child with a new box of crayons. We saw amazing hummingbirds, like the Crimson Topaz with its incredibly long tail, and a Sooty-capped Hermit on her nest. At a wetland, we found two Pinnated Bitterns in flight and a bird that is called, a Double-striped Thick-knee. Now, who would think up a name like that for a bird!? Fortunately, birds don’t care what we humans call them.

We found a Rufous Crab-Hawk in the mangrove swamp. To me, it seemed logical that the primary food of a bird called a Crab-Hawk would be crabs. As we motored through the mangroves on increasingly larger waterways, I kept expecting to arrive at the ocean, where there would be a beach with a flourishing crab colony. However, after at least two hours of boating, we didn’t appear to be anywhere near the beach. Eventually, our Venezuelan guide pointed to two large hawks perched high above the mangroves with no beach in sight. I wondered just where it was that these hawks could find enough crabs to sustain themselves in the unlikely crab habitat. That is, until we pulled over close to the mangroves to look at a flycatcher, only to discover the trees were literally crawling with crabs, big and small. They skuttled up and over the roots and raced up the tree trunks. They are a species of tree crab, at home in this aquatic environment, and so numerous they plunked into our boats with regularity.

As I think about all the marvelous birds of Venezuela, and choosing only three of them, there is one that brings a smile to my face each time, the Scarlet-horned Manakin. We came upon a male deep in the rainforest, a little fellow with a crimson head and a jet black body. We watched as he performed his unique courtship moonwalk dance in the style of Michael Jackson. I’ll never forget the abandon with which he danced – as if no one were watching. Check out another manakin species dancing. http://www.youtube.com/watch?v=PDYpW3zyXqQ
If you are interested in more trip details, I’ve posted photos and stories about the trip on my other blog.

But, as exciting as my South American adventure was, there was immense comfort as I turned my car onto NM 4 and drove into the Jemez Valley. I stopped at the Highway 4 coffee shop for my favorite latte, and chatted with some of the folks there. Ponderosa Drive had just been bladed, for better or worse, and the birds at my place were hungry. My neighbors down the hill invited me over for dinner later this week, and I am thrilled to be back. There’s no place like home.

All About Eagles

Bald Eagle photograph by Doug Brown

A dedicated raptorphile, I once said that if I could see a wild Harpy Eagle in the South American jungle, I would die a happy woman. Harpia harpyja is the only member of the genus Harpia. It is the largest and most powerful raptor found in the Americas, inhabiting tropical lowland rainforest in the upper canopy layer, where it preys on sloths, monkeys, and other tree-top dwelling animals.

Throughout the world, there are 46 species of eagles, including fish eagles, to which our national bird, the Bald Eagle, belongs, and booted eagles of the family Aquila which includes the other well-known North American eagle, the Golden Eagle. There also is a large group of hawk eagles, none of which might be found in the United States. While many birding afficionados consider only the bald and golden native to our land, another eagle, even larger than the bald occasionally graces Alaska and the northern seacoast with its presence, the Stellar’s Sea-eagle. This species which can weigh up to 20 pounds dwarfs our eagles which rarely weigh more than 10 pounds. It normally nests on the east coast of Russia, but often takes to open water during the non-nesting season, sometimes straying as far as North America.

Our beloved national symbol, the Bald Eagle is probably the most instantly recognizable raptor in the world. However, despite its symbolism, the species has suffered from persecution, and until recently was a federally listed species. At one time Bald Eagles occupied almost all of North America and estimates placed the population prior to 1800 at more than 250,000 individuals. However, as humans began to expand our range on this continent, eagle populations began to decline. In the American West, Bald and Golden Eagles were considered vermin and were shot in the mistaken belief that they were a threat to livestock.

In 1940, the Bald Eagle Protection Act made it a federal offense to kill Bald Eagles everywhere except Alaska. In America’s frontier state, however, they still offered a bounty for eagle carcasses as late at 1953. Then, in 1967, they were listed as endangered under the original version of the Endangered Species Act.

Although direct persecution diminished, the species still suffered from low reproductive success. As a top predator, they were a victim of bioaccumulation. Because most of the bald’s prey is aquatic, either fish or waterfowl, toxins from pesticide residues built up in their systems, causing thinning eggshells and reproductive failure. Populations of Bald Eagle, along with Osprey and Peregrine Falcon crashed as a result of DDT and related toxins. Essentially, these large predators were the ‘canary in the coal mine’ that warned us of these pesticide hazards.

Bald Eagle numbers have rebounded thanks to a more enlightened citizenry, the banning of DDT, and laws that protect not only the birds, but also their nests. Now, in many areas, an active Bald Eagle nest is cause for celebration, and eagle watches and eagle cams are the rage. When it comes to nesting, Bald Eagles may just be downright hospitable. Other smaller species sometimes build their nests in the massive structure that the eagles improve upon each year. These smaller birds receive protection from the presence of the larger predator, and the eagle doesn’t necessarily view a small-medium sized songbird as a food item. At one eagle’s nest along Puget Sound, three live nestling red-tails were found. Because the hawks were younger than the eaglets they could not have hatched from eggs laid before the adult eagles arrived. It is likely that the adults brought the chicks to nest to feed their young. But, they were not killed. Under the right conditions, if a nestling makes a food begging call, the parents treat it as just another mouth to feed. Two of the three red-tail chicks fledged from their surrogate eagle’s nest.

Although Bald Eagles have rebounded, much concern remains about the Golden Eagle population in North America. Some biologists believe that golden numbers are as low or lower now than the Bald Eagle was when it was listed. Goldens face some of the same threats to survival, persecution from shooting and also electrocution on power lines. With their large wingspan of 6-1/2 feet, they can easily span the distance between energized components on utility structures.

There is a thriving black market for raptor feathers in North America, especially eagle feathers. While Native Americans can legally possess feathers under permits issued by the U.S. Fish and Wildlife Service for use in religious ceremonies, collectors often pay exorbitant prices for feathers, feet, and skulls. Ironically, some of the largest documented eagle-poaching rings have involved Native Americans.

International trade in raptors is a continuing threat worldwide, and more than 120 countries have signed the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), the most comprehensive wildlife conservation agreement ever created. Appendix I includes some 700 species of plants and animals that are critically endangered, including the Bald Eagle, and no legal trade is permitted in these species. Appendix II includes 3,000 animals, including the Golden Eagle, and 21,000 plants that would be threatened by uncontrolled trade, and only limited trade is allowed under certain circumstances. Appendix III includes species already protected by existing laws of signatory countries, but not included in the other two appendices. I

Which brings us back to the Harpy Eagle which was listed on Appendix I in 1975. For me, this species epitomizes the ultimate birding challenge: rugged conditions, bugs and snakes, potentially unstable politics, and the other hazards of travel in a country with only my marginal grasp of the language. I never for a moment thought that one day I might actually have an opportunity to see one of these magnificent creatures. That is, until the day my friend, Sam, called and said, “Jim Black is leading a tour to Venezuela to look for Harpy Eagles! Wanna go?” So, what could I say, except, “You betcha!” Sam and I are off later this week, along with 6 other birders, on a special quest to see our dream bird. Oh, and the several hundred other species that reside there! So, there won’t be a bird article in the March 1 issue of the Thunder. Hopefully, I’ll have the rest of the story for you in mid-March! Bien Venidos.

Gallant in Gray: Townsend's Solitaire

Townsend's Solitaire photograph by Jerry Oldenettel

Stoically perched atop the tallest snag near the top of the canyon, he surveyed the valley below. Camouflaged by dusky gray plumage, he was nearly indistinguishable from the lighter gray skeleton that had once been a one-seed juniper. From this lofty vantage point, rivals could be as easily detected as winged predators that might threaten his very existence. Outwardly calm to the casual observer, he issued a single note call, “Tew,” sometimes repeated in a series, announcing his territory and warning others to stay away.

Although it was winter, he jealously guarded his turf and its bounteous crop of juniper berries. In fact, his very life depended on the berries so ferociously guarded, for they made up about 95% of his winter diet. It would take between 42,000 and 84,000 juniper berries, depending on berry size, to survive the winter season. He had won the right to this particular berry patch in the fall with up to six fights per hour with others of his kind who would usurp the territory. Now, with winter territories firmly established, he could relax his guard, albeit slightly.

Both sexes of Townsend’s Solitaires establish individual territories around patches of junipers in the autumn, and fiercely defend them until late winter. Territories range from very small, containing as few as two junipers, to quite large, up to 12 acres, containing several hundred junipers. Almost all territories hold more berries than necessary to sustain their owner throughout the long winter. Boundaries are sharply defined, and protected even from members of the opposite sex. Individuals are strongly site faithful to their winter territories, returning to defend the same set of trees each year.

By March, as daylight hours increase, this slender gray thrush experiences the hormonal surges that drive males and females to pair up and establish nesting territories. Like other thrushes, the male sings a complex, hauntingly beautiful song during a display flight, similar in some ways to other members of this family, which includes American Robin, Hermit Thrush, and Mountain and Western Bluebirds. After attracting a female to the territory, he cements that season’s relationship by either regurgitating food to the female, or offering berries. During the spring and summer, spiders and insects, particularly moths and butterflies make up a large portion of their diet.

However, domestic bliss may not reign supreme in solitaire land, as both males and females have been known to indulge in extra pair copulations. By mating with more than one individual, each clutch has a higher degree of genetic variability, essentially a safety net to produce the most fit offspring. Females also have been documented laying eggs in the nests of other solitaires, thus increasing their chances of producing successful offspring with little extra energy demands.

Like other members of thrush family, immature solitaires are heavily spotted. Each feather is edged in black giving the young bird the appearance of a heavily ornamented scallop design on its body. The first time that I saw a juvenile solitaire, many years ago in Bandelier National Monument, I was at a complete loss as to how to identify it. On closer inspection though, the bold white eye ring that both youngsters and adults show, helped me to figure out the identity of the bird.

Because of its specialized winter diet, Townsend’s Solitaire is heavily dependent on juniper woodlands, a particularly under-appreciated habitat type. Throughout the West, many grassland restoration projects focus on large-scale removal of juniper in an attempt to create more forage for cattle and other browsing animals. Loss of mature trees and their berry crops affect not only the solitaire, but also other pinyon/juniper dependent birds such as Gray Vireo, Juniper Titmouse, Pinyon Jay, and both species of bluebirds. Although populations of solitaire appear to be stable currently, there is growing concern about the entire suite of birds dependent on pinyon/juniper woodland.

To learn more about Townsend’s Solitaire, including the song and “Tew” call, visit www.birds.cornell.edu Look at the menu bar across the top of the page, and click on Bird Guide. This will bring up a search page where you can enter any North American species. Generally, for each species account, there is an audio clip.

I would like to thank Jerry Oldenettel for providing the photograph for this article, and I look forward to sharing more of his wonderful photographs in the future. You can view more of his nature photos on his website.

Birds of Winter - Rosy Finch

Black Rosy-finch photograph by Doug Brown

One wouldn’t ordinarily think that birding the high mountains in the dead of winter would be a good idea. First of all there is all that snow: it makes the basics of getting around challenging as well as noisy, and stealth downright impossible. It would seem that all birds might flee with the advance of a large two-legged mammal crunching along through the snow. Such is not the case however, at least in certain parts of New Mexico.

Several years ago, a friend and I stumbled upon three new life birds while cross-country skiing along the open waters of East Fork of the Jemez River. Being neither quiet nor stealthy, we encountered a smallish flock of rosy-finches was feeding on the rock walls that line the canyon. They seemed oblivious to our presence as they flitted over the rock face searching for food. Among the flock were individuals that appeared to be markedly different. Indeed, in recent years, they have been classified as three separate species: Gray-crowned Rosy-Finch, Black Rosy-Finch, and Brown-capped Rosy Finch.

In summer, the Gray-crowned Rosy-Finch is distributed from coastal and western Alaska and British Columbia to the mountains of Idaho, western Montana, and northern California. The Black Rosy-Finch breeds high on scattered mountaintops in the Great Basin, and the Brown-capped Rosy-Finch is limited to the southern Rockies. In winter, the three species may be found together at high elevations in Colorado and New Mexico, most reliably at ski resorts such as Loveland, Colorado, and Taos, New Mexico.

Of the three species, the Black Rosy-Finch (Leucosticte atrata) is the least studied of all birds found on our continent, due to its choice of nesting locations. Only three people known to recorded scientific literature had ever found a nest of the Black Rosy-Finch before 2002. With Global Information Systems (GIS) technology and strong mountaineering skills, a University of Wyoming student became the fourth – when she discovered a nest at an elevation of nearly 12,000 feet in Utah's Uinta Mountains. The difficulty of exploring the Black Rosy-Finch breeding habitat has severely limited scientific study of the birds and made finding one of the nests a rare event.

In late spring, the alpine birds migrate to their nesting grounds above the timberline. There, among the tundra tussocks amid craggy cliffs, the rosy-finches build their nests inside cliff crevices and among the large boulders found on talus slopes. At an elevation of 10,000-13,000 feet, generally in the most remote regions of the Rocky Mountains and on the edges of the Great Basin, these hardy finches set up housekeeping and rear their young in nature’s most challenging environment.

On the nesting grounds, males defend a floating territory around their mates, rather than an area with a defined boundary. As a result, males constantly chase other males that approach their mates too closely. The best way to locate females is simply by watching the center of all the fighting.

In winter, the feisty, territorial birds assume a more gregarious lifestyle, and can be found in large mixed flocks of all three species of rosy-finches. The birds roost in large communal sites in caves, mine shafts, on rafters of barns, and in clusters of old Cliff Swallow nests.

It had long been known that one might find rosy-finches at the well-stocked feeders of the condos near the Taos Ski Area, but elsewhere they were considered to be rare, appearing only sporadically in the dead of winter. There was no reliable site where the birds might be found. This changed when birders Ken and Mary Lou Schneider responded to a Rare Bird Alert in the dead of winter and drove to the top of Sandia Peak (10,678 feet). The skies were clear and the winds calm on that day, and 40-50 rosy-finches of all three species were present foraging along the edges of the parking lot.

Thus began a fledgling plan that has, today, grown into one of the premier winter birding locations in North America. With the blessing of the US Forest Service and the staff of the Crest House, the feeders are always stocked much to the delight of birders that travel here from throughout the world to bag three different lifers in a single day. What is even more remarkable is that many of the feeders are within easy viewing of the tables in the coffee shop, eliminating the need to brave the elements. The dedicated folks that manage this site also run a banding station to track the birds’ movements, and they also maintain an extensive website www.rosyfinch.com The rosy-finches arrive in November and can stay as late as March, although the latest sighting occurred in April.

While I would love to direct you to a more local site in the Jemez Mountains to view these remarkable birds, your best bet to check off all three rosy-finches would be to drive up to the top of Sandia Peak on the next sunny, calm day, buy a cup of hot chocolate or two, park yourself next to the window near one of the feeders and wait. I might just see you there!

Shades of Cimarron

Rough-legged Hawk. Photograph by Douglas Brown

Flash back to two years ago, December 13, 2006. The day dawned cold and dreary, matching my trepidation about what was to come. The old red-tail had been limping for some time, and although the vet assured me that it was just arthritis, I doubted his judgement. Now, it appeared that her foot was rotating inward and she seemed to be in pain. I feared the worst, the big “C”, which is what my gut said. As I was getting ready to take her in for yet another set of X-rays, the phone rang.

I heard the deep voice of a man who said, “I found this hawk alongside the road. It’s been in my garage for two days and a garage is no place for a bird. If you won’t come and get it, then I’ll take care of it myself.” He sounded both kindly and crusty, like an old rancher who had seen much. I knew that he meant every word. I asked where he lived and he responded, “Roy”, a four-hour drive from Albuquerque. Fortunately, Ron, our raptor biologist, was available, and offered to drive up immediately to see what the bird might be. When we get these types of calls, speculation is rampant among the staff as to what we will actually find.

I once got a call from a couple that had an injured ‘eagle’ in their urban back yard. Sure enough, when I arrived, they had it locked in a tin shed, in an eagle-sized box. However, the box seemed lightweight for such a large bird. We brought the box out into the sunshine, and I opened it to reveal – a common nighthawk, a very small insect-eating bird that weighs about a quarter pound. But, that’s another story. On this day, Ron and I both agreed that he would be picking up a Ferruginous Hawk, common on the plains of northeastern New Mexico. Ron drove off to the north at the same time as I drove south to the vet.

Indeed, the news was not good. It would be the old gal’s final day as this set of X-rays clearly showed the deteriorating, twisting bones, eaten alive by cancer. I tried to put on a brave face, but oh, how this hurt! She had been my first bird, the one that inspired me to pursue this line of work. Tears streamed down my face as I sat, typing at my computer waiting for whatever Ron would bring back to the office.

He arrived an hour after the red-tail was gone, not the expected species, but instead a majestic arctic bird, a Rough-legged Hawk. He had an elbow injury, an old healed wound evident in the set of X-rays. He would not ever be able to fly well enough to be released and he joined our staff of educational ambassador as soon as the federal permits were processed.

Rough-legged Hawks nest in tundra or taiga in arctic and subarctic Alaska and Canada, and migrate over the boreal forest to winder in southern Canada and the northern United States. In New Mexico, they appear only occasionally and not at all in some winters. Only when frozen conditions to the north limit food availability, do ‘roughies’ move this far south. And, they generally are observed only from December-February.

How could it be that the bird had been in New Mexico long enough to have been injured, healed and fortuitously found alongside the road? He would have had to arrive by about October, much earlier than expected for this species. He was plenty fat, and showed no evidence of recent trauma. Who would have cared for him so well that every feather was absolutely perfect? He also was an adult, and knew that he belonged in the wild. Yet, he was relatively calm around his human captors. Many mysteries shrouded the majestic northern hawk stranded in the Southwest, never again to see his Arctic home.

We now have two years under our belt, and our relationship has grown. Training a wild bird to a public life in captivity always has its challenges and he was especially wary. He already was an adult bird, had known life in the wild, and possibly produced offspring. Being condemned to a cage, albeit large enough for flight, and forced to interact with a human on a daily basis was hard for him. For my part, I just wanted to gain his trust so that I might someday get close enough to pick him up.

The first year was spectacularly unsuccessful, with little evidence that he would one day be calm enough to display in public. Our Fish and Wildlife Service permit requires that each educational ambassador complete a minimum of twelve programs annually, and I began to wonder if he would ever reach that goal. Each morning, when I would deliver food, I would stay near and talk, sometimes about nothing, sometimes just sing-song words, but always in calm tones. As much as possible, I tried to reassure him that it would be okay, that I would never hurt him, and that we had to make this work as there were no other options.

Then, on one momentous day a few months ago, he trusted me enough to lower his head and eat in my presence, exposing his vulnerability. It was just one mouse, but it was a new threshold. Today, I can sometimes lay the mice at his feet, but not always. At other times, I only can approach within about three feet. He still retains his spirit and his wildness. I am thrilled and humbled to be a part of his life. He’s completed his 12 programs in 2008, and perhaps you will get to see him one day at a presentation. We call him Cimarron del Norte, refugee from the north.

The Water Ouzel, an Ecological Indicator

American Dipper - Photograph by Tom Kennedy

We donned our cross-country skis at the East Fork of the Jemez River, expecting nothing much more than a glorious winter outing in a beautiful canyon. Brilliant sunshine belied the actual temperature as clouds of condensation fogged our glasses. The novice among us worried about the skill level required for the outing, as she clipped her spankin’ new boots in to her equally virgin cross country skis. As a winter wonderland, the Jemez back country is easy to access and provides a more solitary experience than the crowded trails of the Sandia Mountains. Only two more cars shared our space, an indicator of the near solitude that awaited.

As we neared the river, a flash of gray in motion caught my eye. A quick flit, and the bird disappeared behind the rocks. It was February, a month where our usual avian companions are the hardy ravens and Steller’s Jays. Most humans would not be expecting a birdwatching expedition but it soon became apparent that this outing would reveal special rewards. Cautiously, and as quietly as possible, we sneaked up to get a better view of the elusive gray bird whose plumage blended so well with the wet rocks. Only rippling, crystal clear water cascaded through the stream that drained the Valles Caldera. However, as we watched, a little gray bird popped up from beneath the surface with an aquatic insect firmly clutched in its bill.

First documented and christened “Water Ouzel” by John Muir, bird and stream once were considered inseparable. Present along fast-moving, clear, unpolluted mountain streams in the American West throughout the year, the American Dipper is almost exclusively associated with water. The behavior and biological adaptations of this aquatic bird are unique, combining aspects of songbirds with those of ducks. Their traits include and incessant dipping, hence the current name, and a blinking white eyelid. They appear frenzied as they dive into water, sometimes at near freezing temperatures, and use their wings to propel them underwater. They walk, swim and dive underwater. Their main foods are aquatic insects which they find under rocks and in crevices. Although insects are captured underwater, the bird brings them to the surface to eat.

Uniquely adapted to this special environment, dippers share many traits of waterfowl, including exceptionally dense feathering that allows them to remain dry and buoyant in the water. When swimming on the surface, they paddle rapidly with feet and wings. One account reports a dipper being swept over the brink of a waterfall in Yosemite. That bird emerged unscathed and flying at the base of the waterfall, only to return to the exact same spot where it had been previously foraging. Like ducks, dippers molt all their flight feathers at once, and are flightless from four days to two weeks. During this time, they are extremely secretive, taking short fluttering leaps and escaping predation by swimming above or below the water’s surface and hiding under logjams, tangled vegetation, or overhanging banks.

In fact, the very presence of an American Dipper in a particular watershed is an indicator of ecological stream health. As a free-flowing river, the Jemez meets the needs of this species, which requires unpolluted waters, free from agricultural discharges, and without clear-cut deforestation that opens habitat, increases water temperatures, and alters the entire aquatic food web. Upon removal of forest, soil becomes compacted, and erosion, silting, and runoff are accelerated.

Healthy dipper populations on upland rivers througout the world indicate healthy river ecosystems. Along the Jemez River, I’ve observed dippers at East Fork, Jemez Falls, and Soda Dam but only during the times of year when the river receives reduced recreational use. During the times when the river receives heavy use, the birds inhabit those areas that are less accessible to humans. At any rate, each dipper observation, regardless of the time of year, tells us that we are doing something right in managing the Jemez watershed.

On the Wing, Over Prairie and Sea

Peregrine Falcon. Photo by David Powell

They’re coming soon, to a forest or shrub stand near you! In fact, many are already here. September is just about the best month to look for migrants winging their way south toward their wintering grounds. It is an especially good time to look for those uncommon species, like Yellow, Canada, Prairie, or even Chestnut-sided Warblers that nest in the northern forests, but winter in Central or South America.

The good news is that huge numbers of migrants can be found in any area with a good supply of insects, often in mixed flocks that just might include that target bird on your wish list. Just about anywhere with good stands of shrubs beneath the cottonwood canopy should host more than enough birds to satisfy your birding appetite. Just find a likely patch and stop and listen. Shortly, you should begin hearing the little chips that tell you songbirds are around. At this time of year, only one thing is on their minds – food! Their entire focus is to add as much fat reserve as possible to help them survive their long migration.

Just as all species look and sound different, their feeding styles vary too. Yellow-rumped and Wilson’s Warblers are very active feeders, flitting about at all levels from ground level to canopy tops. Watch for motion in the leaves that indicates a songbird is actively feeding. For others, like MacGillivray’s Warbler and Common Yellowthroat, a forceful chip note arising from near ground level in dense vegetation reveals their presence. Still others, like our resident Virginia’s and Grace’s Warblers, tend to skulk in the vegetation, moving slowly and deliberately, often evading detection. And, lastly, there are those that never make a sound, like Warbling Vireo. Luck has to be on your side to detect them.

Although the songbirds moving south through New Mexico have a land-based migration, many species in eastern North America have evolved to migrate over the Gulf of Mexico. Their southbound journey exactly coincides with hurricane season. Have you ever wondered how birds cope with the wrath of Mother Nature at her most ferocious? So far in 2008, Gustav, Hannah, and Ike have affected an already perilous journey, one in which there is no natural respite for an exhausted bird.

It is clear that hurricanes have a devastating effect on migrants caught in the storm, with some estimates of hundreds of thousands dead as a result of a single powerful hurricane. Seabirds, in particular, have nowhere to seek shelter on the open waters. Birds caught up in these storms are blown far off course, often landing in inhospitable places or simply arriving too battered and weak to survive. Although the toll may be extreme on individuals, healthy bird populations are able to withstand such losses, and have evolved to do so. However, severe storms can have devastating consequences for endangered species. Such was the case in 2007, when all 18 endangered Whooping Crane youngsters drowned in their protective cage in the lowlands of Florida following an unexpected storm surge.

There is evidence that birds are sensitive to changes in air pressure and instinctively take shelter. A sharp drop in barometric pressure indicates a big storm is on the way. Some birds fly away from the storm’s path, while strong-flying birds, like the Peregrine Falcon, fly ahead of the storm. In 1998, a second-year, female peregrine was captured in Virginia, and fitted with a satellite transmitter. Scientists monitored her migration southward to Venezuela, including during the extreme weather created by Hurricane Mitch. The peregrine initially followed a track that would have taken her island hopping along the eastern Carribean. As Mitch’s winds altered the normal southerly flow that aids migrating birds, she was pushed toward the west into the open waters of the Gulf. Suddenly, over open water, the falcon appeared to stop for nearly two hours, apparently taking refuge on a ship. For the next three days, she moved against the prevailing winds in a direct line toward Galveston, at a speed of ~10 miles per hour, again presumably on a ship. She rested near there for six days before departing in a southeasterly direction, again possibly hitching a ride on a ship based on her average departure speed. She arrived in Venezuela approximately five weeks later after a sojourn in the Yucatan Peninsula.

Although, much has been published about the effect of Hurricane Katrina, little has been written about its impact on avian migrants. One study, conducted by U.S. Geological Survey scientists, used radar ornithology to measure the effect of the storm on migrant use of lowland forested wetlands of the Pearl River and upland pine-dominated woodlands near Slidell, LA. Their study used archived Doppler weather radar data to measure bird use of this particularly important stopover location. What they found was that for the 3 weeks following Katrina, when virtually all vegetation had been stripped in the wetlands, the birds foraged in the less heavily damaged pine uplands. However, about five weeks after the storm, when much of the surviving forest in the Pearl River bottoms began to sprout new foliage, a corresponding increase of migrant use of the lowlands was documented.

Ultimately, the real threat to birds may not be from Earth’s natural forces, but rather human alterations to the planet that reduce or eliminate surge-protecting coastal wetlands and warming ocean waters that generate increasingly more powerful storms.