Summary: Journal of Animal
Ecology 2004
73, 1089­1101
© 2004 British
Ecological Society
Blackwell Publishing, Ltd.
Low proportions of reproducing hemiclonal females
increase the stability of a sexual parasite­host system
(Rana esculenta, R. lessonae)
H.-U. REYER, M.-O. WÄLTI, I. BÄTTIG, R. ALTWEGG* and B. HELLRIEGEL
Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
Summary
1. The number of reproductive events per lifetime affects all levels of ecological
complexity, including the structure and dynamics of species communities. Here we
investigate a sexual parasite­host system with two water frog species of which one
(Rana esculenta, E) is a hemiclonal hybrid that depends on one of its parental species
(R. lessonae, L) for successful reproduction. Previous theoretical models have shown
that relative fecundities are important for the species composition and stability of this
system, but empirical data from natural mixed LE-populations were lacking.
2. We used three different methods to estimate the proportion of annually reproducing

Source: Altwegg, Res - Avian Demography Unit, Department of Statistical Sciences, University of Cape Town

Collections: Environmental Sciences and Ecology