Scottish Crossbill
|
|
| Scottish Crossbill Conservation status: Data deficient | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Scientific classification | ||||||||||||||
| ||||||||||||||
| Binomial name | ||||||||||||||
| Loxia scotica Hartert,, 1904 |
The Scottish Crossbill (Loxia scotica) is a small passerine bird in the finch family Fringillidae.
This bird breeds to a small extent in the native Scots pine (Pinus sylvestris), forests of central Scotland, but (perhaps surprisingly), rather more often in forestry plantations of exotic conifers, notably Larch (Larix decidua and L. kaempferi) and Shore pine (Pinus contorta). It is currently listed as the only bird species endemic to Great Britain, but its taxonomic status is controversial, often being considered a race of either Parrot Crossbill or Common Crossbill, both of which breed within its range. The population is less than 2000 birds. It nests in pines or other conifers, laying 2-5 eggs.
This crossbill is resident, and is not known to migrate. This species will form flocks outside the breeding season, often mixed with other crossbills.
The crossbills are characterised by the mandibles crossing at their tips, which gives the group its English name. They are specialist feeders on conifer cones, and the unusual bill shape is an adaptation to assist the extraction of the seeds from the cone. The Scottish Crossbill appears to be a specialist feeder on the cones of pines (Scots pine and Shore pine) and larch, though its diet is not yet fully investigated.
Adult males tend to be red or orange in colour, and females green or yellow, but there is much variation.
This species is extremely difficult to impossible to separate from Common and Parrot, and plumage distinctions are negligible. The head and bill size is intermediate between and overlapping extensively with the other two, and extreme care is needed to identify this species. The metallic jip call is probably the best indicator, but even this needs to be recorded and analysed on a sonogram to confirm the identity.