Biology subjects

Feutry, P.

Publications and source records attributed to Feutry, P..

2 recordsLinked to original sources

bioRxiv2022

Rapid estimation of cryptic adult abundance and breeding dynamics in a critically endangered elasmobranch from close-kin mark recapture

AbstractElasmobranchs are one of the most highly-threatened vertebrate taxa. Estimating abundance of spawning adults is often extremely challenging, yet crucial for prioritization of conservation measures. Emblematic of these challenges, the speartooth shark (Glyphis glyphis, Muller and Henle, 1839) was initially known only from rare specimens collected in a few tropical regions river systems of Australia and Papua New Guinea. Listed as critically endangered in Australia (where only six adults have ever been recorded) and endangered by the IUCN, such scarcity and limited distribution prevent direct assessments of abundance or reproductive biology. We used close-kin mark-recapture to estimate the abundance of mature G. glyphis in a genetically isolated population in the Wenlock River, Queensland, Australia. From 224 juvenile/sub-adults and 2 adult samples taken over three years (2013-2016), 46 half-sibling and 33 full-sibling pairs were found. The adult population was estimated at 897 (80% Credible interval 531 - 1684) with a sex ratio (based on mitochondrial DNA) highly skewed to males (females - 0.09: males - 0.91). Based on juveniles sampled in different years that shared a mother, 71% of females were estimated to skip-spawn. In an average year we estimate 44 breeding females occupy the system. Importantly, these methods constitute a viable and relatively rapid approach to obtain robust estimates of absolute abundance and other key population parameters for similar rare species.

ecology↗

bioRxiv2021

Close-kin methods to estimate census size and effective population size

The last two decades have witnessed rapid developments and increasing interest in use of (1) genetic methods to estimate effective population size (Ne) and (2) close-kin mark-recapture (CKMR) methods to estimate abundance based on the incidence of close relatives. Whereas Ne estimation methods have been applied to a wide range of taxa, all CKMR applications to date have been for aquatic species. These two fields of inquiry have developed largely independently, and this is unfortunate because deeper insights can be gained by joint evaluation of eco-evolutionary processes. In this synthesis, we use simple analytical models and simulated pedigree data to illustrate how various factors (life-history traits; patterns of variation in individual reproductive success; experimental design; stochasticity; marker type) can affect performance of the estimators. We show that the Ne/N ratio and the probability of a close-kin match both depend on a vector of parental weights that specify relative probabilities that different individuals will produce offspring. Although age-specific vital rates are central to both methodologies, for CKMR they can potentially bias abundance estimates unless properly accounted for, whereas they represent the signals of genetic drift that Ne estimation methods depend upon. Coordinating Ne and CKMR estimation methods using the same or overlapping datasets would facilitate joint evaluation of both the ecological and evolutionary consequences of abundance.

evolutionary biology↗