Conflicting effects of microhabitat on long-toed salamander movement: implications for landscape connectivity

Background/Question/Methods: Understanding the dispersal ecology of species requires multiple lines of indirect investigation, from the study of patterns of population connectivity across landscapes to the identification of specific factors impacting movement at local scales.To determine the potential effects of microhabitat on landscape connectivity in a small-bodied vertebrate, we experimentally evaluated movement, moisture loss and habitat choice in response to five common substrates. Specifically, we tested the efficiency with which long-toed salamanders (Ambystoma macrodactylum) move across deciduous broadleaf and coniferous leaf litter, grass, moss and sand when motivated to move. We then quantified moisture loss in each of these substrates and evaluated salamander preference for these substrates as resting habitat. 

Results/Conclusions: Our results point to a discord between substrates that are easily traversed and substrates that offer high levels of protection against desiccation. Habitat choice appeared to balance these two aspects of substrate suitability, with salamanders choosing a substrate that offered both low resistance to movement and high protection against desiccation. This result was influenced by the availability of cover as salamanders sought out wetter but less easily traversed substrates when supplemental cover was available. Overall, our results highlight the potential for landscapes to have conflicting effects on individual behaviour and suggest that the link between individual behaviour and broader patterns of population connectivity may be context-dependent.