Effects of egg and hatchling harvest on American alligators in Florida

Harvest of crocodilian eggs and young for captive rearing (ranching) has be en used worldwide as an option for producing crocodilian skills and meat fr om wild stock. The long-term effects of harvesting a certain proportion of early age class, wild American alligators (Alligator mississippiensis) with out repatriation is unknown. We removed an estimated 50% of annual producti on of alligators on Lakes Griffin and Jesup in central Florida over an 11-y ear period and monitored population levels via night-light counts. Densitie s of the total alligator population increased (P < 0.037) on all areas. Cou nt densities of adult (greater than or equal to 183 cm total length [TL]) a lligators increased (P < 0.003) on harvest areas but remained stable (P = 0 .830) on the control (no han est) area, Lake Woodruff National Wildlife Ref uge (Lake Woodruff NWR). Observed densities of juvenile (<122 cm TL) alliga tors remained stable (P > 0.117), and subadult (122-182 cm TL) alligators i ncreased (P < 0.011) on han est areas. The density of juveniles on the cont rol area increased (P = 0.006), and the density of subadults showed some ev idence of increasing (P = 0.088). No changes were detected in size distribu tions on the treatment areas. Nest production, as observed from aerial heli copter surveys, increased (P < 0.039) on Lake Woodruff NWR and Lake Jesup a nd showed some evidence of an increase on Lake Griffin (P = 0.098) during 1 983-91. A 50% harvest rate of eggs or hatchlings did not adversely affect r ecruitment into the subadult or adult size classes.