The 30th RSPB Big Garden Birdwatch was held over the weekend. The aim is to record the highest number of each species of bird visiting a garden or local park, during one hour on the 24th or 25th of January.
The survey started in the late 1970s, when the junior membership of the organisation were asked to count the birds in their garden over one weekend. This “one-off” idea grew into the world’s biggest bird survey. The RSPB collate all the records, which provide an extremely important snapshot of the UK’s garden birds each winter, and scientists use the results to prioritise bird conservation work.
Over the years the surveys have highlighted decreases in some species and increases in others, such as a decline in the average numbers of house sparrows and starlings and a dramatic decrease in song thrush populations. There have been increases in the numbers of some species such as wood pigeons, collared doves and several species of tit.
The top 10 birds nationally in the 2008 survey were, in order of average numbers per garden: house sparrow, starling, blackbird, blue tit, chaffinch, woodpigeon, collared dove, robin, great tit and goldfinch. The Shetland results for 2008 were starling, house sparrow, blackbird, hooded crow, feral pigeon, collared dove, common gull, woodpigeon, herring gull and robin.
It is interesting to compare the average number of the top three garden birds in Shetland with the national averages. For the top bird, the starling, the figures are 21 compared with 3.4, the house sparrow is 11.2 compared with 3.6 and the blackbird is only slightly less numerous in gardens here, at two compared with a national average figure of 2.5.
My own 2009 survey results compare very well to the Shetland 2008 numbers, with 20 starlings, 12 house sparrows, four blackbirds and one robin (robin is 0.2 in the Shetland 2008 survey and 1.3 nationally).
In Shetland, house sparrows are common breeding residents, choosing to nest near human habitation. They are also a very sedentary species, rarely moving more than a few kilometres from their breeding sites.
One of the longest recorded movements of a house sparrow is 70 km – a sparrow ringed in Fair Isle in 1969 was caught on Foula.
Highly gregarious birds, they can be found in large flocks outside the breeding season, but generally live in loose social groupings within an area. Their main diet is grain and seeds, but they also eat items such as shoots, berries, buds, peanuts and household scraps. Another prominent bird species in the week of Lerwick Up-Helly-A’ is the raven, the bird depicted on the banner. Ravens are first mentioned in a Shetland court statute in 1615, but these birds were here long before the 17th century.
It is recorded that the early Norse explorer Floki came to Shetland searching for young ravens on his way to Iceland. Floki used the ravens to help navigate, releasing them at sea and watching in which direction they flew before setting his course.
While he was here, his daughter drowned in an accident on the Loch of Girlsta, the deepest loch in Shetland. Girlsta is a corruption of the girl’s name, Geirhilda. The Norse held the raven in high esteem and their god Odin was known as the Raven God as he had a pair of tame ravens which brought him back everything that was said. The most famous of the Viking standards, the “Landeyda or land-ravager”, depicted a raven.
Today the raven is considered as a fairly common breeding resident and a scarce passage migrant.
It is estimated that there are about 200 raven nest sites in Shetland, the most favoured sites being sheltered geos. These large, impressive birds form life-long pair bonds and can live for 50 years or more.
Joyce J M Garden