Fourteen fresh animal carcasses were monitored throughout decomposition in a mixed flatwood forest in East Baton Rouge Parish, LA, from 5 October to 7 December 1999 (fall) and from 18 January to 30 March 2000 (winter). Species composition and residency patterns of necrophilous insects were documented for four animal species per seasonal experiment: one Louisiana black bear (threatened species), two white-tailed deer, two alligators, and two swine (experimental reference). Results suggested variation in species composition associated with temperature (fall versus winter conditions) and carcass type. In total, 89 species from 39 families and three classes were manually collected from the seven fall carcasses. Ninety-five species from 38 families and three classes were collected at the seven winter carcasses. Overall arthropod diversity was greatest for fall deer and winter swine carrion. Fall alligator carcasses were associated with fewer taxa than the three mammal species during both seasons. The hairy maggot blow fly, Chrysomya rufifacies (Macquart), was the dominant species of the fall study, impacting developmental rates and overall carrion community structure. The winter study was characterized by prolonged carcass decomposition and reduced insect activity due to fluctuating ambient temperatures.