STAGE-FREQUENCY AND HABITAT SELECTION OF A COHORT OF PSEUDACRIS-OCULARIS TADPOLES (HYLIDAE, ANURA) IN A FLORIDA TEMPORARY POND

An analysis of major demographic characteristics of a cohort of Pseuda cris ocularis tadpoles was performed under natural conditions. The stu dy was carried out in a temporary pond within the Lower Suwannee Natio nal Wildlife Refuge, in Florida, USA. Five developmental stage-groups were established. Several samples were taken at different times during development of the cohort. The pond water-level was nearly constant t hroughout the study. The main results obtained were: (1) the mean time to metamorphosis was 7.31 d; (2) the tadpoles spent more time at stag es 33-36 (2.42 d) than at other stages; (3) the shortest developmental stages were 25-28 (only 0.99 d); (4) the survival rate was 10.3%; (5) the range of the survival rate for the five stage-groups was 47.1-73. 6%; (6) the estimated unit time survival rate was 73.3%; (7) the life expectancy (e(x)) for a tadpole just hatched was 3.07 d; (8) the survi val curve (l(x)) was comparable to a Type II curve; and (9) the value of H (entropy) was 0.824. The tadpoles spent more time at the peripher y than in the centre of the pond. Significant differences in water tem peratures between the peripheral and central sampling units were obser ved.