An Experimental Investigation of Landscape Resistance of Forest versus Old-Field Habitats to Emigrating Juvenile Amphibians

摘要: Abstract: We used an experimental approach to investigate the effects of landscape composition on initial dispersal success juvenile amphibians. Larval amphibians—spotted salamander (Ambystoma maculatum), small-mouthed (A. texanum), and American toad (  Bufo americanus )—were added artificial pools in four arrays forest edges. Each array consisted a pool surrounded by circular drift fence with pitfall traps two 2.5 × 50 m enclosures (runs) extending into old-field habitat. Juveniles captured at fences were individually marked released either field or runs. determined distance, rate, total net distance moved juveniles versus from recaptures also conducted 24-hour dehydration trials compare rates evaporative water loss spotted salamanders forest. Initial orientation toads was significantly biased toward Orientation did not differ random expectations. The avoidance open-canopy habitat particular indicates that predictions behavior based adult use may be misleading. Spotted almost times farther more than three field, recapture both species much lower field. attribute shorter distances higher mortality due desiccation abundance predators. Juvenile experienced greater Our data movement suggest habitats offer resistance dispersing some species. Thus, fragmentation is likely reduce between local populations these species, potentially negative consequences for population persistence altered landscapes.