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Agonistic behavior, a critical component of territoriality, is widespread throughout terrestrial plethodontid salamanders, though geographic variation in this behavior is poorly understood. Using color polymorphic Eastern Red-backed Salamanders (Plethodon cinereus), we conducted same-sex laboratory trials to compare aggressive and submissive behaviors between two genetically distinct groups in northern Ohio. For each group, we tested 120 individuals from 3 populations. We predicted that the genetic group with a single color morph would exhibit a higher degree of agonistic and territorial behavior compared to the genetic group with two morphs as an adaptive consequence of altered social dynamics in monomorphic populations. Contrary to our prediction, laboratory trials demonstrated that residents from the polymorphic group were significantly more aggressive than residents from the monomorphic group. This finding was corroborated by a strong residency effect in the polymorphic group, an effect that was weaker in the monomorphic group. Our results suggest that individuals in the polymorphic group are more aggressive and territorial than individuals in the monomorphic group, signifying a greater propensity to secure a territory and defend it against intruders. Our results add important insight into how geographic variation and differences in morph frequency can be attributed to behavioral differences. [ABSTRACT FROM AUTHOR]

Invasive earthworms are rapidly transforming detrital communities in North America. Recent studies have investigated the effects of European earthworms, whereas Asian earthworms, such as species of the genus Amynthas Kinberg, 1867, remain understudied. Amynthas is a surface-dwelling earthworm that voraciously consumes the litter layer of temperate forest floor habitats. The accumulation of detritus is important for the terrestrial Eastern Red-backed Salamanders (Plethodon cinereus (Green, 1818)) because this microhabitat provides the matrix through which salamanders travel when foraging, searching for mates, and dispersing. We examined the effect of Amynthas on the activity of 'naive' (no history of co-occurrence with Amynthas) and 'experienced' (recent co-occurrence with Amynthas) salamanders in laboratory microcosms. We hypothesized that earthworms would disturb normal salamander activity through the reduction of leaf litter and physical impediment, with greater negative effects on naive salamanders encountering this 'novel' invasive species. Consistent with published studies, earthworm presence significantly decreased leaf-litter mass over time. Prior experience with earthworms did not appear to influence salamander response. However, earthworm presence had a significant effect on salamander activity, with salamanders exhibiting increased movement, cover-object use, and co- occurrence under cover objects with earthworms as the study progressed. Unnecessary movement has the potential to incur fitness costs to salamanders in the form of energetic expenditure and increased exposure to predators. Key words: Plethodon cinereus, Eastern Red-backed Salamander, Amynthas, crazy snake worm, Megascolecidae, non-native, leaf-litter community, physical disturbance. Les lombriciens envahissants transforment rapidement les communautes detritiques d'Amerique du Nord. Si des etudes recentes se sont penchees sur les effets des lombriciens europeens, les lombriciens asiatiques tels qu'especes du genre Amynthas Kinberg, 1867 demeurent sous-etudies. Amynthas est un ver de terre vivant a la surface du sol qui consomme voracement la couche de litiere d'habitats de tapis forestier de forets temperees. L'accumulation de detritus est importante pour les salamandres cendrees (Plethodon cinereus (Green, 1818)) terrestres parce que ce microhabitat constitue la matrice a travers laquelle les salamandres se deplacent quand elles s'approvisionnent, cherchent un compagnon ou se dispersent. Nous avons examine les effets d'Amynthas sur l'activite de salamandres<< naives>> (aucun antecedent de cooccurrence avec Amynthas) et << experimentees>> (cooccurrence recente avec Amynthas) dans des microcosmes en laboratoire. Nous avions postule que les lombriciens perturberaient l'activite normale des salamandres en reduisant la couverture de feuilles mortes et les obstacles physiques, les effets negatifs les plus importants etant sur les salamandres naives mises en presence de cette << nouvelle >> espece envahissante. Conformement a des etudes publiees, la presence de lombriciens se traduisait par une diminution significative de la masse de la litiere de feuilles mortes dans le temps. Une experience prealable de la presence de lombriciens ne semblait pas influencer la reaction des salamandres. La presence de lombriciens avait toutefois un effet significatif sur l'activite des salamandres, qui presentaient des augmentations, au fil de l'etude, de leurs deplacements, de l'utilisation d'objets de la litiere et de la cooccurrence avec des lombriciens sous les objets de la litiere. Les deplacements non necessaires pourraient entrainer des couts relatifs a l'aptitude pour les salamandres sous forme de depenses d'energie et d'une exposition accrue aux predateurs. [Traduit par la Redaction] Mots-cles : Plethodon cinereus, salamandre cendree, Amynthas, lombric gris, megascolecides, non indigene, communaute de litiere de feuilles mortes, perturbation physique., Introduction Invasive species are considered one of the greatest threats to biodiversity (Simberloff and Rajmanek 2010). The ability of exotic species to predate, infect, and outcompete native species has reduced [...]

Behavioral repeatability greatly affects the capacity of an individual to respond to varying environments. When multiple behaviors within individuals are repeatable and correlated across time or across contexts, it is termed a behavioral syndrome. However, not all behaviors exhibit the same level of repeatability, and relatively few studies have examined repeatability in amphibians. We examined the repeatability of foraging behavior in the Eastern Red-backed salamander (Plethodon cinereus), a color-polymorphic terrestrial salamander, following a simulated predation attempt. We tested several hypotheses: (1) Simulated predation would negatively affect foraging, increasing latency to feed and decreasing the number of prey items eaten in a fixed time period compared to a control group; (2) Because striped color morphs of P. cinereus are more aggressive, striped individuals would exhibit "bold" behavior by resuming foraging sooner and consuming more prey; and (3) Foraging behavior would be more repeatable for males. We found that the predation treatment inhibited foraging behavior, although neither morphs nor sexes differed in either forging metric. The number of prey eaten was repeatable for all groups of salamanders. Latency to feed, however, was not repeatable for control salamanders. Simulated predation induced repeatable latencies, but when morphs and sexes were analyzed separately, only unstriped and male salamanders were repeatable, suggesting characteristics of these groups related to behavioral syndromes drive this response. We speculate that the greater repeatability of the unstriped morph's latency to feed may result from more frequent encounters with predators in the leaf litter matrix while foraging. Striped salamanders from the source population, in turn, exhibit greater territorial success, and thus may experience more variation in encounters with predators and conspecifics over the course of their lifespans. Our results illustrate the need to carefully define the behavior and subset of the population to be tested when studying behavioral repeatability or behavioral syndromes. [ABSTRACT FROM AUTHOR]

Several studies suggest that small terrestrial salamanders are important regulators of leaf litter arthropod communities, and likely contribute to ecosystem processes such as decomposition and nutrient cycling. Despite the recognition that salamanders have the potential to strongly affect ecosystem function through both direct and indirect pathways, little is known regarding the nature of interactions between small vertebrates and the large, predatory arthropods with which they share both microhabitat and prey. Our study was designed to explore interactions between Eastern Red-backed Salamanders, Plethodon cinereus, and spiders in the genus Wadotes in an eastern North American temperate forest ecosystem. We were particularly interested in teasing apart behaviors such as territoriality and intraguild predation in an attempt to determine specifically which interaction is most likely responsible for the observed negative relationship between salamander and spider abundance at our field site. Field data indicate that P. cinereus and large syntopic spiders exhibit negative spatial associations in the microhabitat beneath cover objects, a possible indication of interspecific territoriality. In our laboratory experiments, resident salamanders displayed agonistic postures similarly toward both intruding conspecifics and spiders, suggesting that salamanders may perceive large intruding spiders as competitors. Finally, we observed no injuries to individual P. cinereus or adult spiders even though occasional chases and bites by both were recorded during the behavioral trials. We found no evidence that adults or juveniles of P. cinereus were envenomated by adult Wadotes spp., and there were no instances of intraguild predation in this study. Multiple lines of evidence from this study, and others, suggest that the primary interaction between individuals of P. cinereus and large spiders is competitive in nature rather than predatory. We suggest that the cost associated with intraguild predation on salamanders with noxious skin secretions may preclude them from being preyed upon by spiders. [ABSTRACT FROM AUTHOR]

The article examines prey availability within the territories of striped and unstriped Eastern Red-backed Salamanders (Plethodon cinereus) and investigates how these differences might influence territorial behavior and diet. Topics discussed include the impact of color polymorphism on prey resources, the role of territoriality in foraging, and the correlation between morph type and prey quality.