Home About Browse Search
Svenska


Population fluctuations in mountain hares

a role for parasites?

Newey, Scott (2005). Population fluctuations in mountain hares. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2005:26
ISBN 91-576-7025-0
[Doctoral thesis]

[img]
Preview
PDF
260kB

Abstract

Throughout their circumpolar distribution mountain hares Lepus timidus show unstable population dynamics characterised by regular and sometimes dramatic changes in abundance. The periodicity, amplitude and degree of cyclicity are different in different regions. The reasons for these fluctuations and geographic differences are not fully understood. In Fennoscandia there is experimental and correlative evidence that some mountain hare populations are limited by predators, but the experiments needed to conclusively demonstrate the role of predators, or of other potential factors have not been undertaken. In Scotland the rigorous control of predators means that the role of predators is largely dismissed, but this has not been experimentally tested. The most promising line of enquiry suggests that intestinal parasites have the potential to destabilise some mountain hare populations. There is paucity of literature from Asia and central Europe and no firm conclusions could be drawn. Time-series analysis of hunting bag records from Scotland largely confirmed the dominance of weak cycles with a mean periodicity of around 9 years found in earlier studies. The analysis of bag records from Fennoscandia found a number of differences compared to earlier studies. We found only limited evidence for the presence of 4-year cycles, and found that the pattern and distribution of cycles has changed in the last 20 years since the fox mange epizootic. Data coverage from central Europe and Asia was very limited and no meaningful conclusions could be drawn. Populations of mountain hares in Scotland show unstable dynamics with 7-12 year fluctuations in abundance. I describe the findings of three studies which tested the hypothesis that intestinal parasites i) reduce female survival, body condition and fecundity, and ii) are randomly distributed within the host population. Parasite reduction experiments suggested that the intestinal parasite Trichostrongylus retortaeformis had little affect on female survival, but reduced female body condition and fecundity. A large scale cross-sectional study revealed that T. retortaeformis was loosely aggregated within the hare population and had a negative affect on body condition. These results are consistent with the hypothesis that parasites may destabilise some mountain hare populations in Scotland.

Authors/Creators:Newey, Scott
Title:Population fluctuations in mountain hares
Subtitle:a role for parasites?
Year of publishing :April 2005
Volume:2005:26
Number of Pages:40
Papers/manuscripts:
NumberReferences
ALLI. Newey, S., Dahl, F. Willebrand, T. & Thirgood, S.J. Mountain hare populations in Eurasia: A review of limiting and regulating factors.(Manuscript). II. Newey, S., Haydon, D.T., Willebrand, T., Aebischer, N.J., Dahl, F.,Smith, A.A. & Thirgood, S.J. Are mountain hare populations cyclic? (Manuscript). III. Newey, S., Thirgood, S.J. & Hudson, P.J. (2004) Do parasites burdens in spring influence condition and fecundity of female mountain hares Lepus timidus? Wildlife Biology 10: 171-176. IV. Newey, S. & Thirgood, S.J. (2004) Parasite-mediated reduction in fecundity of mountain hares. Proceedings of the Royal Society of London. B. 271: S413-S415. V. Newey, S., Shaw, D.J., Kirby A., Montieth, P., Hudson, P.J., & Thirgood S. J. (2005). Prevalence, intensity and aggregation of intestinal parasites in mountain hares and their potential impact on population dynamics. International Journal for Parasitology 35: 367-373. VI. Newey, S., Bell, M., Enthoven, S., & Thirgood, S.J. (2003) Can distance sampling and dung plots be used to assess the density of mountain hares? Wildlife Biology 9: 185-192.
Place of Publication:Umeå
ISBN for printed version:91-576-7025-0
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L20 Animal ecology
Subjects:Not in use, please see Agris categories
Agrovoc terms:hares, population dynamics, parasites, trichostrongylus, population density, scandinavia, scotland
Keywords:mountain hare, Lepus timidus, population dynamics, limitation, regulation, macroparasites, cycles.
URN:NBN:urn:nbn:se:slu:epsilon-607
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-607
ID Code:808
Department:(S) > Institutionen för skoglig zooekologi
Deposited By: Scott Newey
Deposited On:11 Apr 2005 00:00
Metadata Last Modified:02 Dec 2014 10:07

Repository Staff Only: item control page

Downloads

Downloads per year (since September 2012)

View more statistics

Downloads
Hits