Factors affecting dispersal and web tenacity in the lampshade spider, Hypochilus pococki Platinick (Araneae: Hypochilidae)

The ability of a species to disperse is a key component in maintaining gene flow and therefore genetic diversity between populations. Dispersal in the lampshade spider Hypochilus, may be adversely affected by their extreme habitat specialization, restricting them to habitats consisting of damp, shaded rock faces in montane regions. These habitats are often patchy in nature and in some areas may be threatened by destructive fragmentation due to human activities. Movement of adult females within a population of Hypochilus pococki Platnick were observed in the Pisgah National Forest, Canton, NC. Eighty-nine individuals were marked within five designated plots. Web use and movement within plots was tracked over multiple visits over a breeding season. Females were shown to have a greater propensity toward web-tenacity than toward movement between web-sites. Individuals that did re-locate were more likely to travel a shorter distance than a greater distance between visits than was expected by chance. Results provide empirical support for previous genetic study conclusions and anecdotal observations that females exhibit limited movement and are therefore dispersal limited. The role that juvenile spiders and mature males might play in maintaining gene flow among populations is discussed as is how understanding the processes of gene flow among Hypochilus populations is critical to the conservation biology of all three species in Western North Carolina