The Herpetological Journal

pp.103-109

Authors: Arturo I. Kehr

Abstract: An analysis of major demographic characteristics of a cohort of Pseudacris ocularis tadpoles was performed under natural conditions. The study was carried out in a temporary pond within the Lower Suwannee National 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 throughout the study. The main results obtained were: (I) the mean time to metamorphosis was 7.3 1 d; (2) the tadpoles spent more time at stages 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 1 0.3%; (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 survival 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 periphery than in the centre of the pond. Significant differences in water temperatures between the peripheral and central sampling units were observed.