From 2001–2005, we collected and individually marked 219 Alsophis portoricensis anegadae from Guana Island, British Virgin Islands, during the months September–October to determine morphometric characters, evaluate incidence of scarring and tail damage, and assess habitat use and activity. Males were longer than females and significantly heavier and heavier per unit length. Sex ratio was almost exactly 1:1 (102 M:104 F). Undamaged tails of males were significantly longer than those of females, but rates of tail damage did not differ by sex. Scarring and tail damage were more abundant posteriorly on the body and tail, and were cumulative, occurring with significantly greater frequency in larger individuals. Most damage was probably attributable to unsuccessful predation attempts by Soldier Crabs (Coenobita clypeatus). We found snakes in all habitats except an open grassy plain. Activity appeared to be bimodal, with a depression during the heat of the day. Although usually diurnal, three snakes were observed active at night. Most snakes were on the ground, but a small number were in water or climbing on vegetation or human-made structures. Most were in full shade and very few in full sun when first observed. Snakes most frequently were sprawled, rarely coiled, and many were first seen while moving.