Effects of stream acidity on non-breeding dippers cinclus cinclus in the south-central highlands of Scotland
Article first published online: 29 JUN 2006
Copyright © 1995 John Wiley & Sons, Ltd
Aquatic Conservation: Marine and Freshwater Ecosystems
Volume 5, Issue 1, pages 25–35, March 1995
How to Cite
Logie, J. W. (1995), Effects of stream acidity on non-breeding dippers cinclus cinclus in the south-central highlands of Scotland. Aquatic Conserv: Mar. Freshw. Ecosyst., 5: 25–35. doi: 10.1002/aqc.3270050104
- Issue published online: 29 JUN 2006
- Article first published online: 29 JUN 2006
- Manuscript Accepted: 2 SEP 1994
- Manuscript Received: 22 SEP 1993
- 1Macroinvertebrate and Dipper Cinclus cinclus abundances and pH were assessed on four rivers in the south-central highlands of Scotland in early winter 1990 to examine the general applicability of Dipper/acidity relationships established during the breeding season (Ormerod et al., 1985; Vickery, 1991).
- 2The most acid waters had the lowest invertebrate biomasses and Dipper densities. Birds on these rivers spent significantly more of the morning foraging and less time at rest, apparently reflecting reduced prey capture rates and hence the greater time required to replace overnight mass losses.
- 3Analysis of published data on seasonal changes in Dipper population densities and individual energetic demands suggests that even accounting for the higher numbers of Dippers in all habitats during autumn and winter, energetic requirements both of individuals and populations are greatest during breeding, when the costs of self maintenance are coupled with the additional demands of chick rearing.
- 4However, from the patterns found here and elsewhere during autumn it appears that the effects of acidity on Dipper populations are important generally during both the breeding and non-breeding seasons.