Grey Falcon

The Grey Falcon, Falco hypoleucos, is a medium-sized raptor native to Australia, and is considered possibly the rarest of its kind. Exhibiting a predominantly grey plumage with white underparts, this elegant bird of prey is a sight to behold. The tips of its flight feathers are darker, and it sports a yellow cere. Adult Grey Falcons measure between 30 to 45 centimeters in body length, with a wingspan stretching from 85 to 95 centimeters, and weigh between 350 to 600 grams. Females are notably larger than their male counterparts.

Identification Tips

When identifying the Grey Falcon, look for its grey upperparts and contrasting white underparts. The yellow cere is a distinctive feature, as are the darker tips on the flight feathers. Juveniles present a darker grey coloration. The bird's size and wingspan are also key identification markers, with females being the larger sex.

Habitat

The Grey Falcon is an endemic species to Australia, favoring the arid inland regions. Its preferred habitats include Triodia grasslands, Acacia shrublands, and lightly timbered arid woodlands.

Distribution

This falcon is found throughout most of mainland Australia, with the exception of Cape York. Sightings are rare across the Nullarbor Plain and in the Great Victoria, Gibson, and Great Sandy Deserts. The species is most commonly observed within arid zones with annual rainfall below 500 mm.

Behaviour

Grey Falcons are often seen in small family groups, typically consisting of an adult pair and one or more first-year birds. They exhibit a hunting behavior and have been observed consuming their prey on the ground in open areas, making them relatively easy to watch during feeding.

Song & Calls

The vocalizations of the Grey Falcon include hoarse chattering, clucking, and whining sounds. These calls are reminiscent of the Peregrine Falcon but are slower and deeper, with a distinctive "kek-kek-kek" or "kak-ak-ak-ak" heard during vocal exchanges.

Breeding

Breeding occurs once annually within the more arid sections of their range, although they may nest twice in abundant seasons or forego nesting during droughts. The Grey Falcon typically uses abandoned stick nests from other birds of prey, often located in tall trees along dry inland watercourses. Clutch sizes range from two to four eggs, which are oval-shaped and average 51x38 mm.

Similar Species

The Grey Falcon can be confused with the Black Falcon (Falco subniger), but it can be distinguished by its lighter plumage and slightly smaller eggs.

Diet and Feeding

The Grey Falcon primarily preys on other birds, particularly those that form flocks and feed on the ground, such as parrots and pigeons. They also consume small mammals, reptiles, and invertebrates like locusts and worms.

Conservation status

The Grey Falcon is classified as Vulnerable, with an estimated 1,000 breeding pairs remaining. Habitat degradation due to grazing and land clearance poses a threat to their survival. However, the species is present in several protected areas, including Sturt National Park, and genetic studies suggest the population may be stable despite low genetic diversity.

Conservation listing

Internationally, the Grey Falcon is listed as Vulnerable and is included on CITES Appendix II. In Australia, it is classified as endangered under the Environment Protection and Biodiversity Conservation Act 1999. Various states within Australia, including Victoria, Queensland, Western Australia, and New South Wales, have listed the Grey Falcon as threatened or endangered, with specific action plans and management strategies in place for its conservation.