THE RESTORATION OF THE MAURITIUS KESTREL FALCO-PUNCTATUS POPULATION

By 1974, the Mauritius Kestrel Falco punctatus had declined to only fo ur known wild birds, including one breeding pair, as a result of habit at loss and pesticide contamination. A conservation project begun in 1 973 has used many management techniques including captive breeding, su pplemental feeding of wild birds, provision of nestboxes, multiple clu tching, egg pulling, artificial incubation, hand rearing and release o f captive-bred and captive-reared birds by hacking, fostering and pred ator control. A total of 331 kestrels were released in the 10 years up to the end of the 1993-1994 breeding season; one-third of these were captive bred, the rest were derived from eggs harvested from the wild. About 257 (78%) released birds survived to independence and 61% of in dependent juveniles survived their first winter. Although at least 71% of ringed birds attempted to breed in their first year, only 38% of t he nests of first-year females successfully fledged young, averaging 1 .7 per successful nest. Older females fledged young from 64% of nests, fledging an average of 2.0 per successful nest. The breeding success of hacked birds was similar to that of parent-raised kestrels, though the clutches of hacked birds tended to be larger. Annual replacement o f birds holding territories averaged 17% for both sexes. By the 1993-1 994 season, an estimated 56-68 pairs had established territories in th e wild with a postbreeding population, including floating birds and in dependent young, of 222-286, Most of the kestrels were in three sub-po pulations, two of which were derived entirely from released birds, Mau ritius Kestrels are relatively sedentary; 89% of ringed birds found ne sting were less than 5 km from their release or fledging site. Since t he pesticides responsible for their decline are no longer used, the nu mber of Mauritius Kestrels should continue to rise through natural rec ruitment. The distribution of suitable habitat suggests that an eventu al population of 500-600 kestrels on Mauritius is possible. Due to its outstanding success, the release programme for the Mauritius Kestrel ended after the 1993-1994 breeding season,