introduction - Pennsylvania Natural Heritage Program

documented in Pennsylvania. It hibernates in relatively small groups compared to other species andthus is more difficult to locate than more colonial species. The area of the BDA is core habitat,including the hibernaculum and adjacent forested areas. The forested areas at the northern end of thetunnel along the West Branch Susquehanna River likely provide important foraging habitat for theanimals when they emerge from hibernation.Threats and StressesThe species can be negatively impacted by disturbances in its hibernaculum during the winter months.Even low levels of noise, heat, or light can be sufficient to disturb this species, and individuals thatare roused out of hibernation may use up the energy reserves needed to survive in the spring.Physical disturbance of the rock surrounding the tunnel or the tunnel entrances could alter internalenvironmental conditions, which may make it unusable for this species.RecommendationsThe tunnel should be left undisturbed during the months of November through March, which is theseason when bats hibernate, and physical disturbances to the bedrock in the area should be avoided.If uninvited human traffic is a problem here, the installation of a special bat gate can serve to bettersecure the tunnel from frequent disturbance. However, the gate must be installed very carefully inorder to prevent rendering the tunnel unusable to bats. Please consult the Pennsylvania GameCommission for assistance with bat gate installation. Blasting and other bedrock disruption should beavoided within at least 400 m of the tunnel entrance. The forested areas at the northern end of thetunnel along the West Branch Susuquehanna River should be left in natural condition, and insecticidespraying should be avoided as the bats depend upon insects for food.Laurel Run & Saunders Run BDADescriptionThis BDA is designated to highlight the extensive forested seep communities that occur along thefloodplains of Laurel Run and Saunders Run, as well as the intact forested watersheds that support theseep communities and the water quality of the stream.Core Habitat Area—The floodplain of Laurel Run is broad in the core area of the BDA, with backchannels and depressions meandering along the base of the slope. The non-saturated portions of thefloodplain have hemlock-tuliptree-birch forest communities: there is a moderate-aged hardwood-tomixed hardwood-hemlock canopy, dominated by yellow birch (Betula allegheniensis) and hemlock(Tsuga canadensis), with green ash (Fraxinus pensylvanica) occasional, a moderate-density shrublayer of rhododendron (Rhododendron maximum) and witch hazel (Hamamelis virginiana), and anherb layer dominated by New York fern (Thelypteris noveboracensis) or needle and thread grass(Brachyelytrum erectum).The seeps and back channels have a diverse wetland flora, including: buttercup (Ranunculus sp.),slender manna-grass (Glyceria melicaria), hairy buttercup (Ranunculus hispidus), Christmas fern(Polystichum acrostichoides), golden ragwort (Senecio aureus), long beech fern (Phegopterisconnectilis), lady fern (Athyrium filix- femina), Northern wood-sorrel (Oxalis acetosella),intermediate wood fern (Dryopteris intermedia), sedges (Carex scabrata, Carex scoparia, Carexintumescens, Carex gynandra, Carex stipata, Carex frankii, Carex torta, Carex leptalea), mad-dogskullcap (Scutellaria lateriflora), cinnamon or interrupted fern (Osmunda sp.), bee balm (Monardadidyma), a chickweed species (Stellaria longifolia), crested wood fern (Dryopteris cristata), marshpennywort (Hydrocotyle americana), jewelweed (Impatiens capensis), marsh marigold (Caltha115