Truly enigmatic declines in terrestrial salamander populations in G reat S moky M ountains N ational P ark

Aim Woodland salamanders (genus: P lethodon ) declined synchronously across many protected areas in E astern N orth A merica by the mid‐1980s, but no cause was attributed to these declines. We hypothesized that the rapid, synchronous loss of several populations of many species was consistent with the invasive pathogen B atrachochytrium dendrobatidis ( B d ), and we resurveyed historic sites to search for Bd in current populations. LocationG reat S moky M ountains N ational P ark. Methods We surveyed 35 sites 2–4 times between M arch and N ovember 2009, quantified community composition and abundance of 72 populations of six species and three hybrids of P lethodon salamanders, and collected 665 skin swabs to detect B d . Results At 22 of the 35 sites, we were unable to find one or more species that were historically present. P lethodon glutinosus and P . teyahalee and their hybrids were less abundant than historically found, P . jordani x metcalfi and P . ventralis were more abundant and the remaining three species fluctuated but showed no net change. Yet, only one of the 665 salamanders was positive for B d . Main conclusions Declines were not associated with particular localities, but occurred in particular species. We conclude that over collecting, logging, and acid rain are unlikely to have caused these population declines, but we were unable to rule out disease or climate change as contributing factors. Population declines of P lethodon salamanders in the Park are substantial and have persisted for 30 years. Determining the cause and the extent of these declines is important for managing this area of global salamander biodiversity.