Effect of introduced ungulates on density, dietary preferences, home range, and physical condition of the iguana (Cyclura pinguis) on Anegada

I examined distribution, population density and structure, diet, habitat us e, home-range dynamics, and physical condition of the Anegada population of Cyclura pinguis using ground surveys, interviews with residents, mark-and- recapture estimates, fecal analysis, feeding experiments, radiotelemetry, a nd life-history data. When compared with a study of 1968: the density of th e extant population at a 43-ha study site was 0.36/ha, as opposed to 2.03/h a. Leaves represented only 38% of dietary volume, in contrast to 71% in 196 8. Fruit comprised 56% of the diet. Well fed individuals of C. pinguis from a relocated population on Guana Island would not eat the leafy components of the Anegada iguanas' diet. Home ranges on Anegada overlapped and were 10 0 times larger than previously recorded. The sex ratio was two males to one female as opposed to 1:1 in 1968. Iguanas had proportionately lower body m ass than animals captured in 1968. population decline on Anegada seems larg ely due to increased competition from live stock, managed in 1968 but now f eral, eating most palatable vegetation from the understory. Predation by ca ts and dogs is also a threat. The total remaining population is estimated a t <200 individuals. A national park designed to protect the endangered popu lation of C. pinguis has been proposed for Anegada.