Does testis weight decline towards the Subarctic?
Hettyey A; Laurila A; Herczeg G; Jnsson KI; Kovcs T; Meril J Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest 1117, Pázmány Péter s. 1/c, Hungary. hettyeya@freemail.hu Interpopulation comparisons of variation in resource availability and in allocation patterns along altitudinal and latitudinal gradients allow insights into the mechanisms shaping the life history of animals. Patterns of between-population differences in female life history traits have been studied intensively across a wide range of taxa, but similar investigations in males have remained scarce. To study if testis weight-a measure of reproductive investment-varies on a geographical scale in anurans, we focussed on the variation in relative testis weight (RelTW) and asymmetry in 22 populations of the common frog Rana temporaria along a 1,600-km latitudinal transect across the Scandinavian peninsula. We found that RelTW decreased towards the north. Body mass and bo
