This content requires Adobe Flash Player version
or later.
Either you do not have Adobe Flash Player installed,
or your version is too old,
or there is a problem with your Flash installation and we were unable to detect it.
Table 4.1. Bird Species that are Included in the Unidentified Groups Unidentified Group 1
Red-throated diver Black- throated diver Great northern diver
Common gull Black-headed gull Kittiwake
Lesser black-backed gull Great black-backed gull
Herring gull Lesser black-backed gull Great black-backed gull
Common tern Arctic tern
Guillemot Razorbill
25. Divers
Unidentified Group 2 Divers
Small gulls
Gulls
Black-backed gulls Large gulls
‘Commic’ Tern Guillemot / Razorbill
Terns Auks
The number of unidentified birds in a group is proportioned to the specific species that are contained within that group based on the relative abundance of the positively identified species in that month’s survey. For example, in the case of kittiwake, the count consists of:
Positively identified kittiwake + proportion of unidentified small gulls + proportion of unidentified gulls
26.
For common tern and Arctic tern no species specific identification is possible (size and plumage features are so close that it is impossible to separate them) and as a result there is no information on which to apportion these two species. They remain grouped in the data as ‘commic’ tern.
27.
The ability to identify bird images to the species level has advanced considerably in recent years with advances in technology, including higher resolution cameras and more refined software to help identify species and measure species-specific parameters. The result is that for the surveys for East Anglia THREE the unidentified groups contained within the data set were limited to: