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Archive for the ‘Hawk | Falcon’ Category

Hawk | Falcon

25 Apr

The falcons of the world are fascinating to many people, both birders and non-birders. They can be found almost anywhere on earth (except Antarctica) and some species coexist well with humans. The sport of falconry (using falcons to hunt gamebirds) goes back many centuries. I suppose the fascination for many is the combination of speed and elegant lines in a lethal predator.

I never quite caught this special fascination with falcons although I think they are very impressive and beautiful to observe (but I can say the same for many other types of birds). Perhaps my “most memorable” falcon is the bird at left, a spectacular Lanner Falcon at the tip of the Sinai Peninsula in November 1981 (the Sinai was then Israeli occupied; it is now part of Egypt). It is particularly memorable because although I took this photo, I have no memory of it. A week before I had tumbled from a second-floor balcony and been knocked unconscious; I was apparently air-lifted to a hospital by the army. There is an entire blank week in my memory here, but I took extensively field notes of my birding during the days after I returned. I also took rolls of film. One roll starts with a close-up of a Bar-tailed Godwit, then the next shot is a blur of brown feathers hitting to godwit, and then a series of the falcon carrying it off to be devoured. Some of my best stuff — and my only recollections are these photos. Its a weird feeling.

While the big falcons are glamorous and get all the ink, I am more emotional about the story of the Mauritius Kestrel (right). Over the sorry history of man’s destruction of birds and their habitats, this is one of the best success stories going. When I first began birding at a more active pace and my thoughts first turned to world birding in 1974, this was considered the rarest bird in the world. There were only two nesting pairs but two unmated individuals — a total of just six birds — left in the world. But conservationists, spearheaded by Tom Cade, Stanley Temple, C. G. Jones and others, got international backing just in time. They developed a captive breeding program and a public awareness campaign. By the publication of Cade’s (1982) Falcons of the World there were 15 in the wild; 1983 ten of those were captured for breeding (see Jones 1980 for more details). The government of Mauritius also increased the sizes of reserves. When I visited ten years later (1992) the program was going so well there were 250 in the wild and many still being raised in captivity. I understand the wild population is now up to 500 or so and all available habitats on the island have been recolonized. Given this dramatic history — an escape from extinction that passed through a genetic bottleneck when numbers were so low — I still consider the Mauritius Kestrel of the “best birds in the world,” even though today’s birder need only visit Mauritius briefly to see one.

Among the falcons, some 13 species are called “kestrels” but all of these are still retained in the genus Falco that includes all the large hunting falcons; together the genus Falco comprises 38 species, or 60% of the Falconidae.

The other species within the Falconidae are scattered among the caracaras — long-legged neotropical birds, some of which include carrion in their diet, the unique Laughing Falcon Herpetotheres cachinnans and the forest-falcons of the Neotropics (many of them secretive), and the pygmy-falcons and falconets of the Old World tropics. The latter are tiny species like this Pygmy Falcon (below; photo by Dale & Marion Zimmerman) of the open plains of East Africa. The small falconets hunt the forests of Southeast Asia, Borneo and the Philippines.

In the New World, the caracaras can be conspicuous. Birds in the “Crested Caracara” group are prime examples. They are very much an open country bird and readily willing to take carrion. This Southern Caracara (above left) on the Brazilian Pantanal has just recently been split from the Northern Caracara Caracara plancus which ranges from south Texas and Florida to northern South America (Dove & Banks 1999). Their ranges are divided by the Amazon River, and the southern species has a uniformly barred back, rump and tail (and breast) unlike the white-chested, black-backed birds north of the river. Other caracaras are forest edge species, often following the rivers through the lowlands and hunting along the banks. The Black Caracara (below) is such a bird. It is widespread in the South American lowlands; here it uses driftwood on a Napo River islet as a hunting post.



The best known falcon is the Peregrine (above in a fine photo by Ed Greaves) which, if I’m not mistaken, has the most extensive range of any bird species in the world. It is a magnificent hunter, dropping from the skies at high speeds on its prey. This photographed Peregrine has just taken, plucked, and eaten a shorebird on a beach in northern California but Peregrines also prey heavily on waterfowl and, in cities around North America, the prey is mostly introduced Rock Doves (feral pigeons). There the Peregrine has adapted to city life by nesting on skyscraper ledges or bridge girders which replicate the conditions of the steep, inaccessible cliffs it uses for breeding in the wilderness.

In the United States, Peregrines were once more widespread and reasonably common but the species suffered precipitous continental declines in the 1960s and early 1970s due to pesticides, shooting, and nest-robbing for falconry. The widespread use of the pesticide DDT caused eggshell thinning; thin eggs easily broke and eventually nest sites were abandoned. By the early 1970s only one pair was known to nest in the California. In my home county (Monterey) Peregrines had historically been known at some 24 nest sites but the last site was abandoned in the mid-1960s. Fortunately the banning of DDT and governmental listing as an Endangered species, aided tremendously by a hands-on recovery program, have returned the Peregrine to a stable healthy population. The recovery effort was spearheaded in the late 1970s and 1980s by the Santa Cruz Predatory Bird Research Group who removed thin-shelled eggs from nests for safe hatching in captivity, returned young to nests and then closely monitored their success. The Ventana Wilderness Society also released captive-reared birds from a hack site above the Big Sur coast beginning in 1986. By 1980 there were again five Monterey County nests occupied that fledged 4 young. The active intervention phase of Peregrine Falcon management ended in my county about 1990. With these management efforts the local breeding population has rebounded; today there are 6-9 nests from Hurricane Pt. south to the San Luis Obispo Co. line, and it is possible that traditional interior sites have been or will be reclaimed.