Less colourful than its North American cousin, this kestrel is a small falcon adapted to living in Mauritian forests. It has short rounded wings and a relatively long tail and legs. It measures 15–18 centimetres from beak to tail and weighs 135–165 grams.
About 90 per cent of a kestrel’s diet consists of Phelsuma geckos, supplemented by other lizards, insects and shrews. Typically, the kestrel breeds once each year, between September and November. It will lay a second clutch of eggs, usually within 14 days, if the first clutch is lost. Clutches are two to four eggs, primarily incubated by the female.
Native only to Mauritius, the Mauritius kestrel was historically found throughout the island. By the early 1970s, its range was reduced to the mountainous Black River Gorges in southwestern Mauritius. Kestrels occupy territories of about three square kilometres in both upland and lowland native forest.
The pre-colonial kestrel population was never large, estimated between 175 and 325 breeding pairs. At one point, however, the population dropped to just four birds. Today, thanks to an intensive breeding and reintroduction program, there are now an estimated 300–500 kestrels in the wild. Most importantly, this includes at least 100 breeding pairs.
The status of this species is still precarious. When the population peaked at 500–800 birds in 2000, the Mauritius kestrel was downlisted to Vulnerable. However, recent declines led to this species being re-assessed as Endangered in 2014.
The original threats of DDT-based pesticides and habitat degradation are now largely gone. However, the limited amount of original habitat that remains in protected parks and reserves means the population will probably never grow large. Although the species is adapting to new habitats, the small population size leaves the kestrel vulnerable to natural disasters such as cyclones.