Oystercatchers care classified together with other waders in the Charadriiformes. These birds all have features that enable them to live successfully in semi-aquatic habitats. Most are more or less restricted to the littoral zone throughout their lives. Until recent times shore birds, Cyster catchers have begun to breed inland in certain parts of their range. Buxton (1961) and Dare (1946) have shown that there has been an increase in the numbers of this species breeding inland in Britain, particularly within the last 30 years. Falla (1966) mentions a similar increase In New Zealand and Hulscher (pen. comm.) reports an extension of their range into North Holland. Baemctopus ostrcilegus longlpes breeds inland on the steppes of Central Russia (Crote, 1931). The use of coastal fields by Oystercotchers in winter also appears to be increasing 0>arer 1966). At present it may only be of localised occurrence being reported from Glamorgan, Lancashire and Aberdeenshire. Consideration of the above points leads to the question - What factors have been responsible for the increase in the use of Inland habitats? It is not possible to study the causes of post events; thus the problem may be approached by Investigating the respective survival values at the present time of breeding Inland and the use of fields In winter. If It is found that advantages are conferred on those birds Involved In these newly acquired habits, then It may be possible to suggest mechanisms underlying the recent changes In habit. The present study was designed to answer the following questions: 1. To what extent do birds feed in fields in winter and what is the resulting survival value? 2, Is there an advantage in breeding inland?
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:592567 |
| Date | January 1968 |
| Creators | Hoppleston, P. B. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602347 |
Page generated in 0.0015 seconds