Scottish crossbill census

Forest Research to determine the availability of the Scottish crossbill’s food, conifer seed in Scotland

News from Forest Research: April 2008

Male Scottish crossbill feeding female at nest
© David Whitaker

The Scottish crossbill (Loxia scotica) is the UK’s only endemic bird species and is on the World Conservation Union (IUCN) red list of threatened species. The bird is dependent on conifer woodlands for survival and is thought to rely on a range of conifer species for food, switching between species in response to seed availability throughout the seasons.

The first ever full census of crossbills is currently underway in Scotland as part of the Statutory Conservation Agency/Royal Society for the Protection of Birds (RSPB) Annual Breeding Bird Scheme (SCARABBS).

One component of the work is a survey by Forest Research to determine the availability of the Scottish crossbill’s food, conifer seed.

Coning assessments are being carried out at selected sites in Scotland on Norway spruce, Sitka spruce, larch and lodgepole pine. At each site, cone production is being scored on a selection of 20 to 24 trees, recording the current year’s cones on spruce and larch, and the green cones on pines (the seeds of which will become available to crossbills in the winter and early spring). This information will then be added to existing data for Scots pine from the Forestry Commission’s Forest Condition Monitoring survey.

The coning data, together with the results of the crossbill survey, will show how the birds use forests and the differing importance of particular conifer species, especially in relation to cone productivity. It will also clarify the birds’ habitat requirements and how best to manage conifer forests to suit their needs.

Information on coning, and therefore their food resource, will be linked to an RSPB national survey of Scottish crossbills, which aims to estimate population size.

For further information see our Scottish crossbill species action plabe research page.


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This and other news stories can be found in the April 2008 issue of FR Eye, our online newsletter.