Green Salamander Estimated Abundance and Environmental Associations in South Carolina
Green Salamanders, Aneides aeneus, are habitat specialists found in narrow crevices of rock outcrops and under flaky bark of trees. The species has a high conservation priority throughout its range and has been negatively affected by habitat loss, climate change, disease, and overcollection. In portions of the Blue Ridge Escarpment population, many historical locations for this species have not been visited since the 1980s or earlier. Across three counties in South Carolina, we conducted visual encounter surveys of known rock outcrops that were accessible, and used binoculars to conduct arboreal surveys in the adjacent forest. We detected Green Salamanders at 30 of the 61 sites surveyed (49.2%). We collected a variety of habitat variables and compared a suite of N-mixture models using an Akaike information criterion framework. Detection probability was positively influenced by time of day. A model of abundance that included aspect, habitat size, and elevation had the most support. Specifically, Green Salamanders were more abundant at larger sites at lower elevations with south-facing slopes. Knowledge of factors that influence population abundance will help guide future efforts to protect the species in the southern portion of its range.Abstract
Inset map at the top shows counties within South Carolina known to contain Green Salamander (Aneides aeneus) localities. From left to right, shaded polygons are Oconee, Pickens, and Greenville counties. The main map shows the known distributional range of Green Salamanders in upstate South Carolina. Expected abundance for Green Salamander at historical localities in the state is represented by circles colored with a gray-scale gradient (with lighter shades being less abundant sites and darker colors being more abundant sites).
Aspect, habitat size, and elevation emerged as the best predictors of abundance for Green Salamanders (Aneides aeneus) in South Carolina (Table 2). The top panel illustrates the effect of aspect on the estimated abundance of Green Salamanders when both habitat size and elevation are held at their mean values. The middle panel illustrates the effect of size on the estimated abundance of Green Salamanders when both aspect and elevation are held at their mean values. The bottom panel illustrates the effect of elevation on the estimated abundance of Green Salamanders when both aspect and habitat size are held at their mean values. All panels include 95% CI.
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