Birds as a common prey for Vipera latastei Boscá, 1878 in southern Iberia. An ecological strategy in arid environments?

Species with wide distributions often exhibit variation in ecological traits across their range, particularly along climatic gradients. An interesting example is Lataste’s viper, Vipera latastei, an endemic species of the Iberian Peninsula that occurs across a wide range of environmental conditions, from the rainiest to the driest regions. Adult vipers primarily prey on small mammals, supplemented by reptiles, and, more rarely, birds, amphibians and invertebrates. However, the relative consumption of the two main prey groups (mammals and reptiles) varies geographically from northern to southern Iberia. Here, we contribute to the knowledge of this species’ ecology by providing new records of birds as prey and in situ photographs of hunting behaviour in southern Iberian populations. Our findings suggest that adult vipers in eastern Andalusia (southern Spain) prey upon and hunt birds more frequently than populations elsewhere within the species’ range. This ecological strategy seems to be mediated by the low abundance of small mammals in the region, which is likely associated with the area’s arid climatic conditions.