| Autor: |
Patterson TA; CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, Tasmania 7004, Australia., Hillary RM; CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, Tasmania 7004, Australia., Kyne PM; Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory 0909, Australia., Pillans RD; CSIRO Oceans and Atmosphere, QLD Biosciences Precinct, 306 Carmody Road, St Lucia, Queensland 4067, Australia., Gunasekera RM; CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, Tasmania 7004, Australia., Marthick JR; Menzies Centre for Population Health, University of Tasmania, Hobart, Tasmania 7000, Australia., Johnson GJ; Department of Industry, Tourism, and Trade, Berrimah, Northern Territory 0828, Australia., Feutry P; CSIRO Oceans and Atmosphere, Castray Esplanade, Battery Point, Tasmania 7004, Australia. |
| Abstrakt: |
The viability of spatially structured populations depends on the abundance and connectivity between subpopulations of breeding adults. Yet, for many species, both are extremely difficult to assess. The speartooth shark is a critically endangered elasmobranch inhabiting tropical rivers with only three adults ever recorded in Australia. Close-kin mark-recapture models, informed by sibling pairs among 226 juveniles, were developed to estimate adult abundance and connectivity in two Australian river systems. Sixty-eight sibling pairs were found, and adult abundance was estimated at 892 for the Adelaide River and 1128 for the Alligator Rivers. We found strong evidence for female philopatry, with most females returning to the same river to pup. Adelaide River males appear largely philopatric, whereas Alligator Rivers males are highly connected to the Adelaide River. From only 4 years of sampling, our results demonstrate that juvenile-only kin pairs can inform simultaneous estimates of abundance and connectivity in a rare and threatened species. |
