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Population dynamics of the sea snake Emydocephalus annulatus

Citation

Shine, Richard; Brown, Gregory; Goiran, Claire (2021), Population dynamics of the sea snake Emydocephalus annulatus, Dryad, Dataset, https://doi.org/10.5061/dryad.qbzkh18hx

Abstract

For sea snakes as for many types of animals, long-term studies on population biology are rare and hence, we do not understand the degree to which annual variation in population sizes is driven by density-dependent regulation versus by stochastic abiotic factors. We monitored three populations of turtle-headed sea snakes (Emydocephalus annulatus) in New Caledonia over an 18-year period. Annual recruitment (% change in numbers) showed negative density-dependence: that is, recruitment increased when population densities were low, and decreased when densities were high. Windy weather during winter increased survival of neonates, perhaps by shielding them from predation; but those same weather conditions reduced body condition and the reproductive output of adult snakes. The role for density-dependence in annual dynamics of these populations is consistent with the slow, K-selected life-history attributes of the species; and the influence of weather conditions on reproductive output suggests that females adjust their allocation to reproduction based on food availability during vitellogenesis.

Methods

Mark-recapture surveys of sea snakes at three sites beside the city of Noumea. Surveys were conducted in january each year from 2004 to 2021.

Funding

Australian Research Council, Award: FL120100074