The Spatial Ecology of the Southern Copperhead in a Fragmented and Non-Fragmented Habitat

Habitat fragmentation may alter the spatial ecology of organisms inhabiting the fragmented landscape by limiting the area of habitat available and altering microhabitat features. I quantified and compared movement of southern copperheads (Agkistrodon contortrix contortrix) in a fragmented and non-fragmented habitat to determine the effects of habitat fragmentation on the spatial ecology of the southern copperhead. Effective distance moved by each individual was measured by the use of thread bobbins attached via medical tape to the posterior quarter of the snake. Straight-line distance moved and occupied area were calculated with the GPS coordinates recorded at each snake sighting. Straight-line distance moved and occupied area did not differ between fragmented and non-fragmented habitats. However, season-specific effective distance moved differed between fragmented and non-fragmented habitats. In fragmented habitats, effective distance moved by individual snakes increased from summer to autumn, whereas, it decreased in non-fragmented habitats. Increased snake movement from summer to autumn in fragmented habitats may have been the result of coinciding increased human activity during this time. Increased exposure of snakes to humans through direct encounters such as outdoor recreational activities and indirect encounters through increased vibrations from vehicles, lawn mowers, and foot traffic may have disrupted endogenous movement behaviors and prompted an agitated movement pattern. I also quantified microhabitat use by the snakes between the fragmented and non-fragmented habitat to determine if microhabitat suitability was influenced by fragmentation. Tracked snakes were located and microhabitat use was measured within a 1m2 quadrat was placed around the snake capture location. Background microhabitats were randomly selected and microhabitat characteristics were quantified. Background sites were assessed as microhabitat available to the snakes but not chosen. Microhabitat characteristics were measured by quantifying the number of trees, woody vegetation stems, herbaceous vegetation stems, percent grass cover, and percent canopy cover. Microhabitat features were similar between the fragmented and non-fragmented environments; however, the number of herbaceous vegetation stems and percent canopy cover were the only model terms that were associated with locations where snakes were observed (BIC = 468, ⍵i = 0.47). It is likely A. contortrix can persist in a variety of habitats in the southeast because their preferred microhabitat features are widely distributed and common in both fragmented and non-fragmented environments