Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.473727
Title: Studies on the Population Ecology of British Bats.
Author: Stebbings, R. E.
Awarding Body: University of East Anglia
Current Institution: University of East Anglia
Date of Award: 1976
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Abstract:
This project involved three major parts which were concerned with some df the factors limiting distribution and abundance of temperate bats. A study of the population ecology of separate colonies of Plecotus auritus and P. austriacus occupying one roost, where the latter is on the extreme edge of its range, provided some interesting results. These two morphologically similar species were apparently exploiting the same, or at least parts of the same, niche. Their individually varying population sizes when combined resulted in an annually stable total. P. austriacus was the more plentiful prior to the long 1962/63 winter but its population crashed and did not recover subsequently. This lack of recovery was probably in part due to the fenales being too few in number to optimise breeding roost temperatures and ensure good breeding success. Low weight bats in hibernation did not produce young the following summer. Bats of both species measured before and after the P. austriacns population crash showed relative increases and decreases in variation and this together with increased variability amongst P. auritus colonies in areas with fewer bat species suggested some character displacement in areas where there was less competition. Geographic variation in Pipistrelluspipistrollus was studied in order to ascertain it, and how, it adapted to changes in climate. It was found that direct correlations existed between June temperature and air heat content with body size, with larger animals occurring in cooler areas. Thus this species appears to behave as a homeotherm to Bergmann's rule. In addition to phenotypic clines there were sudden changes in size which could be due to different genotypes. Rhinnlonhus ferrume t urn was studied in Dorset because it was declining in numbers and range, The likely reasons were climatic change, loss of roosts or direct human effects leading to reduction in survival. tJhilo no proof was forthcoming for the first, the later two causes were shown to have reduced bat numbers.
Supervisor: Not available Sponsor: Not available
Qualification Name: Doctoral Thesis - University of East Anglia. Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.473727  DOI: Not available
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