BRITISH ECOLOGICAL SOCIETY PRESS RELEASE

17 June 2005

Logging leads to rise in primate parasite infection

Increased rates of parasitic infection could be contributing to the decline in populations of certain primate species, ecologists have discovered. The research, published online by the British Ecological Society's Journal of Applied Ecology, sheds new light on the way in which habitat destruction can affect primate populations and hence has important implications for primate conservation.

Dr Thomas Gillespie and colleagues from the University of Florida and the US Wildlife Conservation Society collected faecal samples from three primate species in logged and unlogged areas of Uganda's Kibale National Park. The three primates they studied have responded differently to logging: populations of redtail guenon (Cercophithecus ascanius) are declining in logged forest, while red colobus (Piliocolobus tephrosceles) populations are slowly recovering and black-and-white colobus (Colobus guereza) numbers are increasing.

Between 1997 and 2002, the researchers collected and analysed more than 1,000 faecal samples from these three primate species. They found that the primate whose population has been declining in logged areas - the redtail guenon - had a larger number and higher rates of parasite infection that redtail guenons in unlogged areas. There was no difference in infection rates in colobus monkeys - the species not in decline - between logged and unlogged areas.

According to Gillespie: "We saw dramatic changes in the prevalence of infection and in the frequency of multiple infections in these logged areas. When you see infection characteristics like these, they can be associated with very detrimental effects on the host."

Although logging is known to reduce abundance of some primate species, the mechanisms responsible for these declines are unclear and the potential role of parasite infection has been largely ignored until now. "Selective logging results in a suite of alterations in host ecology and forest structure that may alter infection prevalence and infection risk in resident populations. Our research establishes that selective logging is associated with altered patterns of parasitism for some species," Gillespie says.

Gillespie and his colleagues found that, unlike the colobus they studied, redtail guenons in logged areas ranged much more widely than those in unlogged areas. This, they suggest, could be responsible for their higher rates of infection.

The results have important implications for conservation. "Knowledge of how particular species are affected by various forms of ecological change is essential to promote land-use policy that is compatible with animal and human health and biodiversity conservation," Gillespie says.

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Notes for editors

1. Thomas R Gillespie et al (2005). Effects of logging on gastrointestinal parasite infections and infection risk in African primates. Journal of Applied Ecology, doi 10.1111/j.1365-2664.2005.01049.x. Copies of the paper are available from Becky Allen, Press Officer, British Ecological Society, tel: 01223 570016, mob: 07949 804317, email: beckyallen@ntlworld.com.

2. For further information, please contact Dr Thomas Gillespie, tel: +256 789 02881.

3. The Journal of Applied Ecology is published by Blackwell Publishing for the British Ecological Society. Contents lists are available at www.blackwellpublishing.com/jpe.

4. The British Ecological Society is a learned society, a registered charity and a company limited by guarantee. Established in 1913 by academics to promote and foster the study of ecology in its widest sense, the Society has 5,000 members in the UK and abroad. Further information is available at www.britishecologicalsociety.org.