Little raven

In the 1960s, the CSIRO were intensively studying Australian raven populations and their relationship to lambing and sheep in southeastern Australia. It became evident that there was a smaller species of raven living alongside the Australian raven. These birds lived in smaller trees, had smaller throat hackles and lacked the bare skin of their larger relative. They were also nomadic and made different calls. Ian Rowley investigated old scientific names assigned to type specimens and concluded that they matched Corvus mellori as described by Gregory Mathews in 1912. The type specimen was collected from Angas Plains in South Australia in 1901. It disappeared in transit in 1966. The little raven is closely related to the other four species of Australian corvid, which include the Torresian crow and little crow as well as the forest raven and Australian raven. Initial single gene genetic analysis of the genus using mitochondrial DNA showed the three raven species to belong to one lineage and the two crows to another. The genetic separation between species is small and there was a suggestion the little raven may be nested within the Australian raven, though the authors conceded more genetic work was needed. Subsequent multigene analysis using nuclear DNA by Jønsson and colleagues in 2012 showed the forest and little raven are each other's closest relatives, with the Australian raven an earlier offshoot. Rowley proposed that the common ancestor of the five species diverged into a tropical crow and temperate raven sometime after entering Australia from the north. The raven diverged into the ancestor of the forest and little ravens in the east and Australian raven in the west. As the climate was cooler and drier, the aridity of central Australia split them entirely. Furthermore, the eastern diverged into nomadic little ravens as the climate became dryer and, in forested refuges, forest ravens. As the climate eventually became warmer, the western ravens spread eastwards and outcompeted forest ravens on mainland Australia but coexisted with little ravens. Rowley proposed the name "little raven" for the new species, conceding it was generic but noting it was demonstrative, and that "little crow" had been adopted over "Bennett's crow" for Corvus bennettii. The term "crow" is colloquially applied to any or all species of Australian corvid. ==Description==

The little raven is, at about 48–50 cm in length on average, somewhat smaller than the Australian raven (though sizes do overlap between both species), the little raven's beak is slightly smaller. The little raven is a somewhat more sociable species than the Australian raven, often forming large flocks that roam freely over wide areas in search of food. Eye colour varies with age: nestlings up to three months old have blue-grey eyes, juveniles aged from three to eleven months have brown eyes, and immature birds have hazel eyes with blue eyerings around the pupil until age one year and eleven months. The eyes turn white when the birds mature into adults. Vocalisations Its call is a harsh, guttural "kar-kar-kar-karrr" or "ark-ark-ark-arrk" with a similarly drawn-out call to the Australian and forest raven. Like all species of raven in Australia (with the exception of the forest raven) the little raven sometimes stretches or flicks its wings outward slightly when calling. Like all corvids, the little raven is capable of vocal mimicry, but this behavior is mostly recorded in captivity and only rarely in the wild. ==Distribution and habitat==

The little raven ranges over southeastern Australia from southern South Australia, Victoria and New South Wales. Also in Kangaroo Island (S.A) and King Island (Bass Strait). Living within scrub, agricultural areas, grazing pasture, woodlands to treeless plains, coasts, and suburbs. Little ravens are absent from west Gippsland, where the land is dominated by forest ravens. Its large range, abundance and stable population mean it is classified as least concern on the IUCN Red List. ==Behaviour==

Breeding Little ravens often nest in a loose colony of up to fifteen pairs, with nests few metres apart. They are closer together as the territories are for breeding only and not feeding, which is more communal. They have often been recorded as having several nests within the nesting territory of a single Australian raven which, presumably due to different food preferences, does not seem to consider them a threat to its own food resources. Cover does not appear to be important as dead trees with bare branches are used. Little Ravens have also been observed predating upon little penguin nests on Phillip Island, where large individual little ravens were found to be more capable of raiding the penguin nests. Little ravens are intelligent birds, and have been recorded using tools as well as having innovative methods of seeking out food. == Explanatory notes ==