UK Group Investigates Decline in Starlings and Sparrows
© Environment News Service (ENS) 2000
November 6, 2000
LONDON, United Kingdom, November 6, 2000 (ENS) - Numbers of house sparrows and starlings, two of the UK's most well known bird species, have declined by 50 percent in farm and woodland areas since 1970.
The long term decline will be investigated by the British Trust for Ornithology (BTO), Environment Minister Michael Meacher announced today.
With the help of 10,000 volunteer members, the BTO has been gathering detailed information on the birds of the UK and Ireland for more than 60 years. It does census work by recording at nests, counting wading birds on estuaries, plotting birds on atlases or ringing (banding) them.
A BTO scheme for weekly counts of birds coming into gardens has more than 5,000 participants.
For its investigation into the decline of house sparrows and starlings, the BTO will lead a consortium of scientists and bird experts from the Royal Society for Protection of Birds, Oxford University, the Central Science Laboratory and Wildwings Bird Management.
The group will try to discover what is causing the decline and, for the first time, examine the trends in urban populations of the two species.
House sparrows (Passer domesticus) were once so common they were considered pests in many regions. When introduced to the United States from the UK in 1852, house sparrows quickly exploited their new habitat, aggressively taking over the nests of native swallows, bluebirds, and house wrens.
It is a 14 centimeter (5.5 inch) brown bird, and males have a black bib. Large sparrow populations were once supported by waste grain from the feed of horses. But the number of sparrows in urban areas declined as horses were replaced by automobiles.
Starlings are any number of birds composing most of the family Sturnidae (order Passeriformes), especially Sturnus vulgaris, a 20 centimeter (eight inch) iridescent black bird with a long sharp bill. They often damage fruit and grain crops but consume harmful insects.
The BTO consortium will map trends according to region and habitat, record winter and summer survival rates, and breeding success, examine human influences, such as pest control, and assess the relative importance of demographic and environmental influences in causing the declines.
Birds have long been regarded as important indicators of environmental change because they are sensitive to differences in atmospheric conditions. The BTO consortium has a mountain of data to start from. Monitoring schemes such as the Common Birds Census, the Garden Bird Feeding Survey, Garden BirdWatch and the Breeding Bird Survey, as well as data from intensive field studies, all point to a drop in numbers of the two birds.
"I share the concerns of all British bird lovers about the significant decline in these species," said Meacher. "I am confident that this major research project will help us to save our sparrows and starlings. It will give us a fresh insight into what is causing the problem and what we can do to reverse the situation."
The 18 month research program will start in December. It will build on research commissioned by the Environment Ministry two years ago, and will attempt to fill in the gaps in knowledge about population trends in urban and suburban areas.
This will involve sophisticated analysis of long term population census data in relation to environmental data sets using newly developed methods. Detailed analysis of bird ringing data, nest record data and detailed information from intensive field studies will be combined in population models to identify the demographic and environmental factors contributing most to population declines.