Natural and anthropogenic substrates affect movement behavior of the Southern Graycheek Salamander (Plethodon metcalfi)

Movement behavior is a critical process that interacts with landscape structure to affect population connectivity and persistence in fragmented or altered landscapes. The purpose of our study was to test whether different substrates (forest litter, soil, grass, gravel, and asphalt) found in fragmented forested landscapes affected the movement behavior of the Southern Graycheek Salamander (Plethodon metcalfi Brimley, 1912). Latency period of the salamanders was highest on grass substrate and significantly lower only on soil substrate. Sinuosity of the movement path of salamanders was lowest and contained more turns in grass and was significantly higher than only gravel and asphalt substrates. Velocity of the salamanders was highest on asphalt substrate but was not different from gravel substrate. Velocity was higher on asphalt than on grass, forest, or soil, and velocity was higher on gravel than on grass substrate. The results indicated that P. metcalfi reacted differently to natural and anthropogenic substrates, and we suggest that these behavioral differences could have both positive and negative implications for movement success and habitat resistance in forested landscapes fragmented by roads and development. Key words: amphibian, connectivity, habitat resistance, movement behavior, roads, sinuosity, Southern Graycheek Salamander (Plethodon metcalfi), substrate, velocity. Le comportement de deplacement est un processus cle dont les interactions avec la structure du paysage ont une incidence sur la connectivite et la persistance des populations dans les paysages fragmentes ou modifies. L'etude avait pour but d'evaluer si differents substrats (litiere, terre, herbe, gravier et asphalte) presents dans des paysages forestiers fragmentes avaient une incidence sur le comportement de deplacement de la salamandre Plethodon metcalfi Brimley, 1912. La periode de latence des salamandres etait la plus longue sur l'herbe, mais ce parametre n'etait significativement plus faible que sur le substrat terreux. La sinuosite de la trajectoire des deplacements des salamandres etait la plus faible et comptait le plus grand nombre de virages sur l'herbe, ce nombre n'etant toutefois significativement plus eleve que le nombre de virages sur substrats de gravier et d'asphalte. La vitesse des salamandres etait la plus grande sur le substrat d'asphalte, bien que cette vitesse ne soit pas differente de la vitesse sur gravier. La vitesse etait plus grande sur l'asphalte que sur l'herbe, la litiere et la terre, et la vitesse sur gravier etait plus grande que sur l'herbe. Ces resultats indiquent que les P. metcalfi ont reagi differemment selon que le substrat etait naturel ou artificiel. Nous postulons que ces differences de comportement pourraient avoir des consequences aussi bien positives que negatives sur le succes des deplacements et la resistance de l'habitat dans des paysages forestiers fragmentes par des routes et amenagements. Mots-cles : amphibien, connectivite, resistance de l'habitat, comportement de deplacement, routes, sinuosite, salamandre Plethodon metcalfi, substrat, vitesse. [Traduit par la Redaction]
Introduction The movement of individuals is a critical ecological process that maintains populations through dispersal and connectivity. Successful movement is especially important in fragmented and altered landscapes for rescue of [...]