Movement patterns, maximum distances traveled and microhabitat selection of spadefoot toad tadpoles in temporary ponds

Abstract

Abstract Understanding the movement of individuals across natural habitats is important to determine fundamental aspects of their ecology, from dispersal patterns and habitat selection to interactions with predators, pathogens or conspecifics. Amphibian larvae are key to aquatic systems, playing fundamental roles as both consumers and prey, affecting nutrient cycling and even physico-chemical properties of the water bodies they occupy. Nevertheless, despite an extensive body of literature on most other aspects of their ecology, we know very little about spatial movements of amphibian larvae in their natural habitats, and the little information we have is restricted to lotic systems. Here we use a mark-and-recapture procedure using elastomers to determine movement patterns and microhabitat selection of western spadefoot toad tadpoles (Pelobates cultripes) in two large ponds in southwestern Spain. We observed maximum distances moved by these tadpoles of >67 m and >245 m, depending on the pond. These distances coincided with the maximum cross distance in each pond, suggesting that they could potentially move even farther in larger wetlands. Mean distances moved were 29.7 and 105 m in each pond. We sampled at two, four and nine days after release of tagged individuals, and we observed a stable, not expanding, movement pattern across sampling dates, suggesting that tadpoles resumed normal activity immediately after release. Tadpoles showed preference for deeper and more densely vegetated areas of the ponds, especially associated with plant species such as Ranunculus peltatus and Potamogeton pectinatus.