Most of the over 100 species of starlings are found in tropical Africa and South East Asia, but a few species breed in temperate regions, including the familiar European starling (usually just referred to as the starling).
Today this species is a widespread breeding bird in Scotland, but at the beginning of the 19th century it was virtually absent, except for the populations in Shetland, Orkney and the Outer Hebrides. By the end of the 20th century, starlings had re-colonised the Scottish mainland. However, the isolation of the Shetland population may have led to the evolution of a distinct sub-species.
Starlings in Shetland are mainly sedentary, although ringing recoveries indicate there is some migration. Immigrants from northern Europe arrive in the islands in autumn but most continue south to Scotland, so that most of the starlings found in the islands during winter are local.
The starling was first recorded as a breeding bird by Thomas Gifford in 1733. The population is now estimated at between 10,000 and 20,000 pairs, with highest densities found in crofting areas. Breeding starlings were present in 42 of the 49 square kilometres covered during the annual Shetland Breeding Bird Survey.
After the autumn moult, the feathers of adult birds are tipped with buff or white, giving them a spotty appearance. During the winter these feather tips wear away, and the plumage becomes glossy black with a metallic green and violet sheen. The dark brown bill also becomes yellow and the feet and legs turn reddish-pink. Sexes are generally alike, but the male has no spots on the breast and has blue-grey at the base of the bill, while the female has some pale spots on the breast and the bill base is creamy-pink. At close range, a female displays a pale ring in the dark brown iris while the male’s eye is uniformly dark brown.
Starlings are essentially birds of grasslands, having evolved a special open-bill technique when feeding. The muscles which open the bill allow the tips of the mandibles to part when the bill is pushed into the surface of the soil. The main diet during the breeding season is leather jackets, the larvae of craneflies or daddy long-legs.
In Shetland these grubs are known as story-wirms and can be serious pests as they eat the roots of grasses. The starling’s feeding technique is highly efficient in locating and removing these harmful larvae. Starlings also eat a variety of invertebrates, including worms, as well as fruit, seeds, nuts and kitchen scraps.
More signs of spring have been recorded this week such as skylark song and the first record of a returning lesser black-backed gull at Wester Quarff (average date for this species is around the 8th March).
Local rarities included the two tundra bean geese in the south Mainland along with a Greenland white-fronted goose and the coal tit which is back at Sandgarth, Voe. There were records of a few chaffinches and greenfinches in Lerwick, a couple of common scoters off Sumburgh, a few glaucous and Iceland gulls, a peregrine falcon at Scatness and a notable count of 60 grey herons near Voe.
Not only birds return to Shetland at this time of year. On the 1st March there were five killer whales at Reawick.
Joyce J M Garden