The Mauritius Kestrel, Falco punctatus, is a small, rare falcon endemic to Mauritius. It symbolizes a remarkable turnaround from the brink of extinction. Its journey from near disappearance to a recovering population highlights the impact of dedicated scientific efforts, demonstrating what focused conservation can achieve in safeguarding biodiversity.
A Unique Falcon’s Profile
The Mauritius Kestrel is a compact falcon, typically measuring between 25 and 29 centimeters in length with a wingspan of 49 to 56 centimeters. Males generally weigh 123 to 178 grams, while females are slightly larger and heavier, ranging from 173 to 231 grams.
Its plumage features rufous upperparts adorned with black barring and spotting on the mantle and wings, complemented by black streaking on its head. The underparts are whitish, marked with black streaking on the upper breast and distinct black spots and chevrons on the lower breast and belly.
This falcon’s natural home is within the native forests, cliffs, and ravines of Mauritius, primarily concentrated in the southwestern plateau. Historically, it inhabited evergreen forests from sea-level up to 800 meters, but its range significantly contracted due to habitat loss.
The kestrel’s diet consists mainly of arboreal geckos, particularly Phelsuma day geckos, which can constitute up to 90% of its food intake. It also preys on small birds, rodents, and various insects like dragonflies, cicadas, and crickets.
The Mauritius Kestrel employs several hunting strategies, including hunting from a perch, in flight, or on the ground. It is known for its ability to hover in the air, similar to a helicopter, allowing it to spot prey from above. This species nests in natural tree or rock cavities, particularly in cliff faces, and has also adapted to using artificial nest boxes provided by conservationists.
On the Brink of Extinction
The Mauritius Kestrel faced a drastic decline, pushing it to the edge of extinction. Its population, estimated between 175 and 325 breeding pairs in pre-colonial times, suffered initial reductions due to deforestation in the 18th century and natural disasters like cyclones. However, the most severe decline occurred in the 1950s and 1960s.
Extensive habitat destruction, primarily deforestation for agriculture and construction, significantly reduced the kestrel’s natural forest home, leaving only a small percentage of native forest remaining. This loss of habitat was compounded by the widespread use of persistent pesticides, such as DDT, from the 1940s to the 1970s. These chemicals, used for malaria control and crop protection, accumulated in the food chain, poisoning the kestrels and causing their eggs to become fragile and crack during incubation.
The introduction of non-native predators further decimated the kestrel population. Invasive species like black rats (Rattus rattus), small Indian mongooses (Herpestes auropunctatus), feral cats (Felis catus), and crab-eating macaques (Macaca fascicularis) preyed on kestrel eggs, chicks, and even adult birds. By 1974, the wild population plummeted to a critically low number, with only four known individuals remaining, including just one breeding female.
A Remarkable Recovery Story
The recovery of the Mauritius Kestrel is recognized as one of the most successful bird restoration projects globally. Beginning in 1973, a comprehensive recovery program was launched by organizations like the World Wildlife Fund and the International Council for Bird Preservation, in collaboration with the Mauritius Forestry Department. This initiative involved a multi-faceted approach, including pioneering captive breeding programs and reintroduction strategies.
Captive breeding played a central role in boosting population numbers. Between 1981 and 1986, fertile eggs and young were collected from the wild, leading to the establishment of a healthy captive breeding stock. By 1993, over 600 eggs had been laid in captivity, with many hatching and producing young. Techniques such as “double-clutching,” where a second clutch of eggs is laid after the first is removed, were employed to maximize reproductive output.
Reintroduction efforts involved releasing captive-bred birds into protected areas, often after a period of “hacking.” Hacking involves placing young birds in nest boxes at release sites and providing food until they can hunt independently, allowing them to adapt to the wild.
Predator control measures were also implemented around nests and release sites, targeting invasive species like mongooses and feral cats through trapping. Habitat restoration initiatives, including replanting native tree species and removing invasive plants, helped improve the quality of the kestrel’s natural environment. These combined strategies led to a substantial increase in the wild population, reaching an estimated 222 to 286 birds by the end of the 1993-1994 breeding season.
Current Status and Ongoing Protection
The Mauritius Kestrel’s population has significantly recovered. By the early 2000s, the population had increased to an estimated 500-600 individuals, leading to its downlisting to “Vulnerable” on the IUCN Red List in 2000. However, recent trends indicate a decline, and the species was re-assessed as “Endangered” in 2014, with estimates placing the current wild population at around 250-400 mature birds.
Despite its recovery, the Mauritius Kestrel continues to face ongoing conservation challenges. Habitat fragmentation remains a significant threat, as only a small percentage of good-quality native forest remains on the island. Invasive plant species, such as the traveller’s palm and strawberry guava, also affect habitat quality and can reduce the kestrel’s hunting efficiency. The persistent threat of introduced predators continues to impact kestrel eggs, chicks, and adults.
Current and future protection strategies involve continued monitoring programs across the island to track breeding activity and numbers. Ongoing predator control around nests and release sites remains a focus. The provision and maintenance of artificial nest boxes are also important, offering secure nesting sites and increasing breeding success, especially where natural cavities are limited. Community involvement and public awareness campaigns also foster support for conservation efforts and ensure the species’ long-term survival.