Addressing challenges in non invasive capture-recapture based estimates of small populations: a pilot study on the Apennine brown bear

摘要: It is often difficult to determine optimal sampling design for non-invasive genetic sampling, especially when dealing with rare or elusive species depleted of diversity. To address this problem, we ran a hair-snag pilot study on the remnant Apennine brown bear population. We used occupancy models estimate performance an improved field protocol, meta-analysis approach indirectly model capture probability, and simulations evaluate effect genotyping errors accuracy capture-recapture population estimates. In spring 2007 collected 70 hair samples in 15 5 × 5 km cells, using 5 10-day trapping sessions. Bear detectability was higher than previous attempt same 2004, reflecting protocols design. However, individual probability 0.136 (95% CI = 0.120–0.152), still below minimum requirements capture-mark-recapture closed models. genotyped (n = 63) at 9 microsatellite loci, obtaining 94% Polymerase Chain Reaction success, 13 genotypes. Estimated PIDsib 0.00594, per-genotype error rate 0.13, corresponding 99% correct identification. Simulation studies showed that non-corrected filtered estimates negligible only >0.2. Our results underline how interaction among protocols, strategies may affect DNA-based small genetically populations, warned us about feasibility survey traditional sampling. similar cases, indications from can provide cost-effective means efficiency designed modelling procedures.