More Birds in Taiwan
SPOTLIGHT ON TAIWAN “Endemic Subspecies of Taiwan birds—first impressions”, by N. J. Collar, from BirdingASIA No. 2, December 2004. Presented with permission. BirdingASIA is the bulletin of the Oriental Bird Club. Please see our Links page for benefits of membership in the OBC.
The Peregrine Falcon is a magnificent bird. It is a raptor; a bird of prey, meaning that it hunts other birds and animals forfood, primarily using its talons (long, sharp, grasping claws). The word “falcon” comes from a Latin word, and refers to the hooked shape of the talons. The beak is also hooked, sharply pointed and strong. “Peregrine” in Latin is Peregrinus, which means “traveler,” “wanderer” or “pilgrim.” Peregrine Falcons are well known for their long fall and spring migratory flights to and from their nesting and wintering habitats.
Peregrines are widespread and are found on all continents except Antarctica. There are at least 25 subspecies. It is a large falcon, about 45 to 50 cm long, from beak to tip of the tail, and with a wingspan of about 1 meter. Females are bigger (averaging about 1/3 larger) and stronger than males. Peregrine body mass varies according to sex, origin, age, time of year and most recent meal; a large female can weigh as much as 1595 g, while a small male can weigh as little as 590 g.
The Peregrine can be identified by its black “hood” and black cheek. Its shape is streamlined, with long, pointed wings for very powerful, fast flight. It has superb eyesight and can see and recognize prey more than a kilometer away. Prey may be spotted from a daytime roost (usually) or while circling high in the sky. Peregrines chiefly hunt birds such as pigeons, doves, starlings, shorebirds, and waterfowl, but will sometimes take mammals (bats, squirrels, rats, mice), reptiles, or insects. It is one of the fastest flying birds in the world. It attacks by power-diving (called “stooping”); the wings are folded so that they are nearly parallel, and the bird dives headfirst toward its prey at speeds that may exceed 300 km/hour. The falcon will then strike the prey with its feet, usually killing it upon impact. The prey may be retrieved in midair or from the ground. Any small-to medium-sized bird can be a target for the falcon; however, colonial nesting birds and those that flock are more likely to be chosen.
Peregrines live in a wide variety of habitats, from sea level to 3650 m (12,000 feet), often nesting on a cliff ledge. The pair mates for life; the life span of the Peregrine is usually 8 to 10 years, but can be as long as 20 years. The female is dominant over the male. Mated pairs will return to the same spot year after year. Part of the mating display involves the pair engaging in amazing aerial acrobatics; power dives, tight cornering, high soaring, and body rolls. In the northern hemisphere, nesting usually takes place in February and March; July to August in the southern hemisphere. Increasingly Peregrines have chosen to nest in cities, on man-made structures such as cathedrals, high bridges, towers, tall chimney stacks and ledges on tall buildings which resemble natural cliff ledges. Both parents participate in incubation and brooding activities, but the female remains at the nest for the majority of the time while the male hunts and brings food to her and the young.
In areas where the Peregrine is a year-round resident, the pair may winter together, but in most parts of the world, the male and female go their separate ways after the breeding season, returning to the nest site and each other for the next nesting season. Sometimes an unmated pair will choose to roost together as a couple for the winter.
In the 1950s and 1960s, the Peregrine Falcon became endangered in some parts of the world, because of overuse of pesticides, especially DDT. Pesticide build-up interfered with reproduction, causing thinning eggshells that would break before chicks could develop and hatch. In some areas, the Peregrine Falcon was wiped out by pesticides. To save the peregrine, conservation measures were taken, and reduction of pesticide use has enabled some populations to recover. The world population is now considered stable.
Because of its strength, intelligence and maneuverability, the peregrine is highly prized by falconers. Peregrine eggs and chicks are often targeted by thieves and collectors, so the location of their nest should not be revealed, unless they are protected.
In Taiwan, the Peregrine Falcon is considered “uncommon in winter” and “rare resident.”
There is only one confirmed breeding record, in northern Taiwan, in 1997 (Dr. K.Y. Huang, pers. comm. Feb. 2007).*
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Peregrine Falcon Story
Two Peregrine Falcons Falco peregrinus, male and female, chose to spend the winter of 2006–2007 in an area of tall apartment buildings in Kaohsiung City, Taiwan. They selected a small, sheltered ledge high on a 22-storey building as their daytime roost. Jason Tu ???, who lives nearby, had the rare privilege of being able to observe the birds and photograph their everyday activities. They departed in the evening for a night roost elsewhere, and returned early in the morning. They were almost certainly the same birds that spent two weeks in March, 2006, on the same ledge.
The female Kaohsiung Peregrine was a juvenile when she was first observed in March, 2006, with an adult male. She (presumed to be the same) was in immature plumage when she returned seven months later (October 2006). She was the primary hunter, bringing a variety of prey, mostly Rock Pigeon Columba livia, back to the ledge. She ate first, not permitting the male to eat until she finished. Her dominance in feeding is typical paired Peregrine Falcon behavior. The two birds apparently did well during the winter of 2006–07.
The two Peregrine Falcons abandoned their Kaohsiung City high-rise ledge in early February, 2007; where they went is unknown, although they were observed in the neighborhood from time to time.
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Document cited: (marked * in text)
*Huang, Kuang-Ying and L. L. Severinghaus. 2005. The nocturnal hunting of a diurnal raptor, the Peregrine Falcon (Falco peregrinus), in southern Taiwan. Proceedings of “Conservation of Asian Raptors through Science and Action,” Asian Raptor Research & Conservation Network, 4th Symposium on Asian Raptors, 28–31 October 2005, Taiping, Malaysia.
Literature and Internet Sources:
A Field Guide to the Birds of China, MacKinnon, John & Karen Phillipps, Oxford University Press, 2000
Ask an Expert—Geoff Holroyd,
Birds of North America Online, Peregrine Falcon Falco peregrinus. White, C. M., N. J. Clum, T. J. Cade, and W. G. Hunt. (2002). Peregrine Falcon (Falco peregrinus). The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North American Online database: http://bna.birds.cornell.edu/BNA/demo/account/Peregrine_Falcon/
Handbook of the Birds of the World - Volume 2: New World Vultures To Guineafowl. 1992, del Hoyo, Josep, Andrew Elliott and Jordi Sargatal,
Hinterland Who’s Who, Canadian Wildlife Service, 2007, http://www.hww.ca/hww2.asp?id=60
Life History Notes: Peregrine Falcon Falco peregrinus, Ohio Department of Natural Resources, 2003 http://www.ohiodnr.com/wildlife/Resources/wildnotes/pub080.htm
Peregrine Falcon, Environment Canada http://www.on.ec.gc.ca/wildlife/wildspace/life.cfm?Lang=e
Peregrine Falcon Falco peregrinus, A Success Story, USFWS, Chesapeake Bay Field Office
Peregrine Falcon, http://users.cybercity.dk/~ccc12787/raptors/peregrinus.html
Peregrine Falcon (Falco peregrinus) http://www.robstewartphotography.com/facts/Falcon.asp?i_id=553
Peregrine Falcon Information, http://www.regencybrighton.com/birds/info/
Raptors of the World, Ferguson-Lees, J. and D.A. Christie, Houghton Mifflin Co., Boston, 2001
What is a Peregrine Falcon? http://www.regencybrighton.com/birds/info/