Mauritius Kestrel
Tagged: animal, animals, bird, cat, insectFalco punctatus
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Reduced to a population of just four wild birds by 1974, the Mauritius kestrel has clawed its way back from the edge of extinction to become a spectacular success story. The island of Mauritius in the Indian Ocean will always be notorious as the former home of the dodo: the universal symbol of extinction. Until recently the Mauritius kestrel seemed bound to suffer the same fate since its numbers had reached a point from which recovery seemed impossible. The Mauritius kestrel hunts like a short winged sparrowhawk. Its relatively short wings give it the maneuverability to pursue prey beneath the canopy of dense evergreen forest that once covered much of the island. It usually hunts from a perch, moving swiftly and swerving through the branches to snatch prey (songbirds, dragonflies, or lizards) from the air or the trees. Among its favorite targets are the iridescent green geckos found only on Mauritius; the kestrel is expert at locating them as they bask, immobile in the sun. Occasionally, it hovers to pinpoint prey in low vegetation, but its wings are not really adapted to the task. It is a bird of the forests. As the forests were felled to provide farmland for a growing population, the kestrel gradually disappeared.
Relentless Decline
Mauritius kestrels have never been abundant. Each breeding pair occupies a large territory, and the entire island is no bigger than a large city. At most there were probably only 1,000 birds. By the 1970s rampant deforestation had eliminated most native forest cover, leaving only a few pockets of habitat in rocky gorges on the southwest of the island. The kestrels were also shot by farmers-who believed they stole poultry 174 and poisoned by pesticides. Their tree nesting sites were vulnerable to the egg-thieving nonnative macaque monkeys, as well as introduced cats, rats, and mongoose. It was a deadly combination, and by 1974 there were just four birds. That season one pair nested in a tree in the usual way, but their nest was raided by monkeys. For some reason the other pair chose to nest in a hole in a sheer cliff. The choice of this unusual nesting site saved the species because the cliff face was monkey-proof. Three chicks fledged, and for the first time in years the Mauritius kestrel population increased. The young birds adopted the cliff-nesting habit when they matured, and by 1976 they had boosted the population to 15 birds. Revival Early attempts to breed Mauritius kestrels in captivity ended in failure. The first success came in 1984, and since then many birds have been bred in captivity both in Mauritius and at the World Center for Birds of Prey in Boise, Idaho. By 1993 there were 200 birds. The object was always to reintroduce the birds to the wild. Released captive-bred birds initially had trouble establishing territories in areas where there were wild kestrels; only about 50 percent of birds released in prime habitat survived their first year. It was assumed that Mauritius kestrels would not thrive in other types of terrain, but the captive-bred birds have proved adaptable. Released into areas of degraded secondary forest, their survival rate after a year is about 80 percent. By the end of the 1999 to 2000 breeding season there were three subpopulations, including between 145 and 200 breeding pairs. At first the birds were sustained by supplementary feeding, nest guarding, predator control, and other conservation measures. But since 1994 there have been no more reintroductions, and apart from careful monitoring, the kestrels have virtually been left to their own devices. The Mauritius kestrel will never be quite safe: Its total population is so small that it will always be vulnerable to natural disasters such as tropical storms and infectious diseases. However, its story shows what can be done, given the will and a little luck.
Statistic
Mauritius kestrel
Falco punctatus
- Family: Falconidae
- World population: About 500-800 birds
- Distribution: Island of Mauritius in the southwestern Indian Ocean
- Habitat: Primarily evergreen subtropical forest, but captive-bred birds released into the wild have colonized degraded secondary forest and scrub
- Size: Length: 8-10 in (20-26 cm). Weight: male 6 oz (178 g); female 8 oz (231 g)
- Form: Small and stocky, with long legs and tail; unusually short, rounded wings for a kestrel. Female bigger than male. Black-barred, chestnut-colored upperparts, black-flecked white underparts, black eye with typical dark falcon “moustache” below; yellow skin on legs and at base of bill. Juvenile has blue-gray facial skin
- Diet: Lizards (mainly tree-climbing geckos), small birds, large insects, and introduced mice and shrews
- Breeding: Naturally nests in tree cavities, but may now use cliff sites and nest boxes; lays 2-5 (usually 3) eggs in August-November; young hatch after 4 weeks
- Related endangered species: Seychelles kestrel (Falco araea); lesser kestrel (FF naumanni)
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