Sex ratio bias and extinction risk in an isolated population of Tuatara (Sphenodon punctatus).

ABSTRACT: Understanding the mechanisms underlying population declines is critical for preventing the extinction of endangered populations. Positive feedbacks can hasten the process of collapse and create an 'extinction vortex,' particularly in small, isolated populations. We provide a case study of a male-biased sex ratio creating the conditions for extinction in a natural population of tuatara (Sphenodon punctatus) on North Brother Island in the Cook Strait of New Zealand. We combine data from long term mark-recapture surveys, updated model estimates of hatchling sex ratio, and population viability modeling to measure the impacts of sex ratio skew. Results from the mark-recapture surveys show an increasing decline in the percentage of females in the adult tuatara population. Our monitoring reveals

SUBMITTER: Grayson KL 

PROVIDER: S-EPMC3979778 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature