Rock crevice morphology and forest contexts drive microhabitat preferences in the Green Salamander (Aneides aeneus)

Little is known about how vertical rock habitats are selected by organisms in forest ecosystems. Multiple lungless salamanders use rock outcrops in the Appalachian Mountains of eastern North America, with Green Salamanders (Aneides aeneus (Cope and Packard, 1881)) showing the strongest associations as an outcrop specialist. Although previous work has identified environmental correlates of rock face and arboreal habitat use in this species, it remains to be known if and how Green Salamanders select crevice refugia as a function of both outcrop morphology and the context of outcrops within the surrounding forest. We performed an intensive survey of an abundant Green Salamander population on Virginia’s Appalachian Plateau to examine which features of vertical habitats are associated with salamander occupancy. Occupancy was highest in deeper rock crevices closer to surrounding trees, a likely consequence of arboreal behavior and the ability for crevice refugia to modulate the surrounding microclimate. Although uncertainty exists with regards to the generality of these results across the species’ range, our results underscore linkages between embedded rock outcrop habitats and their surrounding forest contexts for amphibians. Our results also provide a model of Green Salamander habitat associations that may be valuable to efforts to elucidate its geographic distribution.

Woody and arboreal habitats of the Green Salamander (Aneides aeneus) in the Blue Ridge Mountains

The green salamander (Aneides aeneus) is primarily considered a rock crevice dwelling species. However, many early observations from Kentucky, Tennessee, Virginia, and West Virginia report A. aeneus taken from woody and arboreal habitats. There have been only four published records of A. aeneus using such habitats within the Blue Ridge Disjunct population of southwest North Carolina, northeast Georgia, and northwest South Carolina, and no records since 1952. Here I report two personal observations of A. aeneus using arboreal habitats in North Carolina. Additionally, I report nine observations, made by others, of A. aeneus using woody, arboreal, or otherwise non-rock-crevice habitats in North and South Carolina, including the first non-rock-crevice A. aeneus nesting record for the Blue Ridge. I also speculate that woody and arboreal habitats play a much larger role in the life-history of A. aeneus than generally thought, and that the rarity of A. aeneus is linked to the loss of American Chestnut and old-growth forests.