Mauritius Kestrel

Q: How many Mauritius kestrels are left in the wild?

Fewer than 250 birds, of which about 140-170 are mature adults, according to the 2018 estimate used by the IUCN. The species was moved back up to Endangered in 2014 after numbers fell from a peak of about 350-500 birds in the late 1990s (BirdLife International).

Q: Why did the Mauritius kestrel nearly go extinct?

Forest clearance and pesticides. Less than 2% of Mauritius's original forest remains, and organochlorine pesticides such as DDT, used in the 1950s and 1960s, poisoned the food chain (BirdLife International). By 1974 only four kestrels were known in the wild, including a single breeding pair (Jones et al. 1995).

Q: How was the Mauritius kestrel saved?

Mostly by hands-on breeding led by Carl Jones from 1979. He fed wild kestrels white mice so they laid more eggs, then took the eggs to incubators so the females laid a second clutch (The Guardian). Between 1984 and 1994, 331 kestrels were released, a third bred in captivity and the rest hatched from wild eggs (Jones et al. 1995).

Q: Did zoos help save the Mauritius kestrel?

Yes. The Peregrine Fund bred 46 Mauritius kestrels at its World Center for Birds of Prey in Idaho from 1988 to 1991 and sent them back to Mauritius (The Peregrine Fund). Kestrels are still hand-reared for release at the Gerald Durrell Endemic Wildlife Sanctuary in Black River, named after the Jersey Zoo founder (MWF).

Q: How is the Mauritius kestrel different from a common kestrel?

It is a forest specialist. Its short, broad, rounded wings help it chase prey between branches, geckos and other lizards make up about 90% of its diet, and males and females look the same, unlike common and American kestrels (The Peregrine Fund). Compare our Peregrine Falcon card.

Falco punctatus

Mauritius Kestrel (Falco punctatus): The Falcon Saved From Four Birds

The Mauritius kestrel is a small, spotted forest falcon found only on Mauritius. Forest loss and pesticides cut it to four known wild birds in 1974, making it the rarest bird in the world. Captive breeding, egg pulling and releases led by Carl Jones brought it back to a few hundred birds, but numbers have fallen again and it is Endangered today.

Habitat: Native evergreen forest, gorges and cliffs; also secondary forest with nest boxes
Size: 17.7-25.5 cm long, 170-227 g
Diet: Mostly Phelsuma day geckos and other lizards, plus insects, small birds and shrews
Range: Only Mauritius: three subpopulations in the east and south-west
Conservation: Endangered (IUCN 2023), 140-170 mature birds (2018 estimate)
Low point: Four known wild birds in 1974

Habitat & range

The Mauritius kestrel lives only on the island of Mauritius in the Indian Ocean. It once lived in forest across the whole island, but by the 1950s it was confined to the remote, steep forests of the Black River Gorges in the south-west (BirdLife red data book; Nicoll et al. 2021). Its main habitat is native evergreen forest, which now survives mostly in the south-west, and less than 2% of the island's original forest remains. Released birds proved more tolerant of secondary forest and scrub, and today the species lives in three separate subpopulations in the east and south-west (BirdLife International).

A falcon built for the forest

This is a small falcon, 17.7-25.5 cm long and 170-227 g. It has a rusty head and back, white underparts covered in dark spots and a barred tail. Unlike common and American kestrels, males and females look the same (The Peregrine Fund). Its wings are short, broad and rounded, which helps it twist between branches in dense forest. It watches from a perch, then dashes after prey, and it can also hover like other kestrels. Phelsuma day geckos and other lizards make up about 90% of its diet, with insects, small birds and shrews on the side (The Peregrine Fund). It nests in cliff and tree cavities and now also in nest boxes, laying 2-5 eggs that hatch after about 30 days (The Peregrine Fund; BirdLife International).

Down to four birds

Clearing the forests started the decline, and organochlorine pesticides such as DDT, used in the 1950s and 1960s on crops and against malaria mosquitoes, finished much of the job (BirdLife International). By 1974 only four Mauritius kestrels were known in the wild, including a single breeding pair (Jones et al. 1995). That made it the rarest bird in the world (Durrell).

Eggs, incubators and nest boxes

A recovery project began in 1973, but the turning point came when Carl Jones arrived in 1979, aged 24, at a time when few people thought the kestrel could be saved (Mauritian Wildlife Foundation; New Scientist). He worked with captive birds and the last wild pairs. He fed wild kestrels white mice so they laid more eggs, then took their eggs to incubators so the females would lay a second clutch, a method called double-clutching (The Guardian). Chicks were hand-reared and released by hacking or fostered to wild pairs, while nest boxes and predator control helped them breed. In the ten years up to the 1993-94 season, 331 kestrels were released: a third bred in captivity, the rest hatched from eggs taken from the wild (Jones et al. 1995). The Peregrine Fund sent falcon breeder Willard Heck to help hatch eggs on Mauritius and bred 46 more birds at its World Center for Birds of Prey in Idaho from 1988 to 1991, which went back to Mauritius (The Peregrine Fund). Jones worked closely with Gerald Durrell's Jersey Wildlife Preservation Trust (now Durrell) and the Mauritian Wildlife Foundation, and he won the 2016 Indianapolis Prize for this work (Durrell).

Falling again

The population peaked at around 350-500 birds and 99 breeding pairs at the end of the 1990s. Earlier estimates of up to 800-1,000 birds are now thought too high (BirdLife International). An island-wide survey in 2007 found about 325 birds, and the small reintroduced population in the Moka mountains had disappeared (Mauritian Wildlife Foundation). The IUCN moved the species from Vulnerable back to Endangered in 2014. In 2018 there were fewer than 250 birds, or 140-170 mature adults. The eastern population is stable at around 50 pairs, but the western one fell below 15 pairs (BirdLife International; Nicoll et al. 2021). Invasive plants, rats, monkeys, mongooses and cats, plus the genetic damage from the bottleneck, are the main threats. More nest boxes are seen as the most practical way to help (BirdLife International; Nicoll et al. 2021).

Fun facts about Mauritius Kestrel

In 1974 only four Mauritius kestrels were known in the wild, including a single breeding pair.
Carl Jones fed wild kestrels white mice so they would lay more eggs, then took the eggs to incubators so the females laid again.
Geckos and other lizards make up about 90% of the Mauritius kestrel's diet.
Unlike common and American kestrels, male and female Mauritius kestrels look the same.
The Peregrine Fund bred 46 Mauritius kestrels in Idaho from 1988 to 1991 and sent them back to Mauritius.

Mauritius Kestrel vs Peregrine Falcon (cousin comparison)

In open sky the peregrine wins. Inside a Mauritian forest, the kestrel's rounded wings give it the edge.

This is a comparison of two cousins, not a fight. Both are falcons in the genus Falco. The peregrine is built for open sky and high-speed dives, while the Mauritius kestrel has short, broad, rounded wings that let it weave between branches and snatch geckos off trunks inside dense forest (The Peregrine Fund). Both were hit hard by DDT-era pesticides, and The Peregrine Fund worked on both. For the Mauritius kestrel it sent a breeder to Mauritius and bred 46 birds in Idaho for release (The Peregrine Fund; BirdLife International).

Common questions about Mauritius Kestrel

How many Mauritius kestrels are left in the wild?

Fewer than 250 birds, of which about 140-170 are mature adults, according to the 2018 estimate used by the IUCN. The species was moved back up to Endangered in 2014 after numbers fell from a peak of about 350-500 birds in the late 1990s (BirdLife International).

Why did the Mauritius kestrel nearly go extinct?

Forest clearance and pesticides. Less than 2% of Mauritius's original forest remains, and organochlorine pesticides such as DDT, used in the 1950s and 1960s, poisoned the food chain (BirdLife International). By 1974 only four kestrels were known in the wild, including a single breeding pair (Jones et al. 1995).

How was the Mauritius kestrel saved?

Mostly by hands-on breeding led by Carl Jones from 1979. He fed wild kestrels white mice so they laid more eggs, then took the eggs to incubators so the females laid a second clutch (The Guardian). Between 1984 and 1994, 331 kestrels were released, a third bred in captivity and the rest hatched from wild eggs (Jones et al. 1995).

Did zoos help save the Mauritius kestrel?

Yes. The Peregrine Fund bred 46 Mauritius kestrels at its World Center for Birds of Prey in Idaho from 1988 to 1991 and sent them back to Mauritius (The Peregrine Fund). Kestrels are still hand-reared for release at the Gerald Durrell Endemic Wildlife Sanctuary in Black River, named after the Jersey Zoo founder (MWF).

How is the Mauritius kestrel different from a common kestrel?

It is a forest specialist. Its short, broad, rounded wings help it chase prey between branches, geckos and other lizards make up about 90% of its diet, and males and females look the same, unlike common and American kestrels (The Peregrine Fund). Compare our Peregrine Falcon card.

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