We studied the southern river otter Lontra provocax and the American mink at five marine sites, where they coexisted,

and at one freshwater Selleck 3-deazaneplanocin A site, where only mink were present, in southern Chile. We used the signs of both species to study their habitat use and diet, and radio tracking to study their activity patterns. The results indicated that otters and minks tended to use different habitats in marine environments, the otter favouring littoral areas that are rocky and steep while the mink favours areas of gravel with a gently sloping intertidal zone. These differences were also reflected in their diets. At one of the coastal sites where the diet of the two species was similar, the activity pattern of minks was mostly diurnal, which is unusual. Daporinad molecular weight While differential habitat use may be the way through which the American

mink is able to coexist with the southern river otter in coastal habitats of southern Chile, it is possible that otters are having an effect on individual minks by affecting their activity patterns, although more observations are needed to confirm this hypothesis. “
“In ectotherms, decreasing season length and lower temperature towards higher latitudes often favour higher growth and developmental rates. However, the underlying physiological mechanisms and particularly the hormonal correlates of clinal variation remain unexplored. The growth hormone (GH) plays a crucial role in growth of all vertebrates and high expression of GH is associated with rapid growth in many species. We tested the hypothesis that GH expression is correlated with a latitudinal gradient in growth in Paclitaxel solubility dmso Scandinavian Rana temporaria tadpoles. Using quantitative polymerase chain reaction, we measured GH and growth hormone receptor (GHR) expression at two time points from laboratory-raised tadpoles originating from eight populations collected along the latitudinal gradient. To explore latitudinal differences in stress-induced changes in GH expression, we also compared GH expression in tadpoles raised with and without predators. In accordance

with previous studies we found a clear latitudinal gradient in growth. There were no latitudinal effects, or predator-induced effects on GH or GHR expression. However, there was some indication for among-population variation in GH expression. The lack of a latitudinal pattern in GH and GHR expression may be due to that the growth promoting effects of GH is dependent on other factors including insulin-like growth factor-I (IGF), IGF-binding proteins or prolactin. Further studies on these factors may provide insight on the proximal mechanisms of differences in growth in R. temporaria tadpoles. “
“Analyses of leopard Panthera pardus prey choice reveal a strong preference for species weighing 10–40 kg.