Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Growth, Reproduction and Residency in a Declining Population of Microtus agrestis

P. N. Ferns
Journal of Animal Ecology
Vol. 48, No. 3 (Oct., 1979), pp. 739-758
DOI: 10.2307/4193
Stable URL: http://www.jstor.org/stable/4193
Page Count: 20
  • Read Online (Free)
  • Download ($18.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Growth, Reproduction and Residency in a Declining Population of Microtus agrestis
Preview not available

Abstract

(1) The population dynamics of Microtus agrestis (L.) inhabiting a young larch plantation in south-west Britain were studied from spring 1967 to spring 1969. As the larch trees grew they shaded out the ground layer vegetation and there was a resultant decline in vole density from 97/ha to 6/ha during the 2 main years of study. By the summer of 1972, this species had disappeared altogether. (2) Vole growth rates were significantly correlated with an index reflecting the abundance and rate of growth of the grasses which formed their main source of food. (3) Despite a good start to the breeding season in 1968, conditions deteriorated rapidly as a result of shading, and there was a considerable rise in perinatal mortality. (4) Rates of residency (minimum survival) were lowest during two main periods of the year. The first, in spring, involved mainly males, and coincided with the onset of sexual activity. The second, in summer, involved mainly females, and coincided with the replacement of overwinter residents by animals of the year. (5) Decreases in the rates of residency were correlated with increases in the distances moved between consecutive captures by male voles, reflecting a concomitant increase in the size of their home ranges. (6) Previously published records of male spring body weights from several parts of Britain were found to be significantly correlated with the standing crop of a meadow at Moor House Experimental Station and with the hay yields of the unfertilized control plots in the Rothamsted Park Grass Experiment. These correlations suggest a link between vole population fluctuations and climate. The effects of the quality or quantity of the spring food supply upon vole growth and reproduction could play an important part in this link.

Page Thumbnails

  • Thumbnail: Page 
739
    739
  • Thumbnail: Page 
740
    740
  • Thumbnail: Page 
741
    741
  • Thumbnail: Page 
742
    742
  • Thumbnail: Page 
743
    743
  • Thumbnail: Page 
744
    744
  • Thumbnail: Page 
745
    745
  • Thumbnail: Page 
746
    746
  • Thumbnail: Page 
747
    747
  • Thumbnail: Page 
748
    748
  • Thumbnail: Page 
749
    749
  • Thumbnail: Page 
750
    750
  • Thumbnail: Page 
751
    751
  • Thumbnail: Page 
752
    752
  • Thumbnail: Page 
753
    753
  • Thumbnail: Page 
754
    754
  • Thumbnail: Page 
755
    755
  • Thumbnail: Page 
756
    756
  • Thumbnail: Page 
757
    757
  • Thumbnail: Page 
758
    758