The ongoing expansion of wolf (Canis lupus) populations has led to a growing demand for up-to-date abundance estimates. Non-invasive genetic sampling (NGS) is now widely used to monitor wolves, as it allows individual identification and abundance estimation without physically capturing individuals. However, NGS is resource-intensive, partly because of the wolf elusive behaviour and wide distribution, but also because of the cost of DNA analyses. Optimization of sampling strategies is therefore a requirement for the long-term sustainability of wolf monitoring programs. Using data from the 2020-2021 Italian Alpine wolf monitoring, we investigate how (i) reducing the number of samples genotyped, (ii) reducing the number of transects, and (iii) reducing the number of repetitions of each search transect, impacted spatial capture-recapture population size estimates. Our study revealed that a 25% reduction in the number of transects or, alternatively, a 50% reduction in the maximum number of repetitions yielded abundance estimates comparable to those obtained using the entire dataset. These modifications would result in a 2,046 km reduction in total transect length and 19,628 km reduction in total distance searched. Further reducing the number of transects resulted in up to 15% lower and up to 17% less precise abundance estimates. Reducing only the number of genotyped samples led to higher (5%) and less precise (20%) abundance estimates. Randomly subsampling genotyped samples reduced the number of detections per individual, whereas subsampling search transects resulted in a less pronounced decrease in both the total number of detections and individuals detected. Our work shows how it is possible to optimise wolf monitoring by reducing search effort while maintaining the quality of abundance estimates, by adopting a modelling framework that uses a first survey dataset. We further provide general guidelines on how to optimise sampling effort when using spatial capture-recapture in large-scale monitoring programmes.

Capercaillie in Scotland have declined in number and contracted in range since the 1970s, most remaining in Strathspey on the northwest flank of the Cairngorm mountains. Strathspey, however, is popular for recreation and suffers anthropogenic disturbance from visitors and their use of new forest tracks and remote, off-track areas. Disturbance reduces the area of forest available to Capercaillie. Refuge areas wherein the creation of new tracks is not allowed, and in which recreation is not encouraged, are a management option that might mitigate such effects. We simulate this possibility for the area covered by Forest and Land Scotland’s Strathspey Land Management Plan. Spatially explicit, stage-based matrix models assessed the potential of protecting this population with refuges under ‘optimistic’, ‘central’ and ‘pessimistic’ scenarios based on observed demographic data. Fifteen potential refuges comprised less-disturbed areas of forest still used by Capercaillie. We simulated population growth using combinations of 1, 3, 5, 7, 10, 12 and the full complement of 15 refuge areas. An increasing Capercaillie population could be sustained by a network of refuges, but refuges could not arrest a wider population decline due to causes other than disturbance. This suggests that refuges could play a role in mitigating the increasingly damaging effects of disturbance on Capercaillie in the Strathspey LMP but that the birds’ long-term prospects will depend upon improving their performance more widely.

As an island endemic with a decreasing population, the Critically Endangered Grenada Dove Leptotila wellsi is threatened by accelerated loss of genetic diversity resulting from ongoing habitat fragmentation. Small, threatened populations are difficult to sample directly but advances in molecular methods mean that non-invasive samples can be used. We performed the first assessment of genetic diversity of populations of Grenada Dove by a) assessing mtDNA genetic diversity in the only two areas of occupancy on Grenada, b) defining the number of haplotypes present at each site and c) evaluating evidence of isolation between sites. We used non-invasively collected samples from two locations: Mt Hartman (n=18) and Perseverance (n=12). DNA extraction and PCR were used to amplify 1,751 bps of mtDNA from two mitochondrial markers: NADH dehydrogenase 2 (ND2) and Cytochrome b (Cyt b). Haplotype diversity (h) of 0.4, a nucleotide diversity (π) of 0.4 and two unique haplotypes were identified within the ND2 sequences; one haplotype was identified within the Cyt b sequences. Of the two haplotypes identified; the most common haplotype (haplotype A = 73.9%) was observed at both sites and the other (haplotype B = 26.1%) was unique to Perseverance. Our results show low mitochondrial genetic diversity, a non-expanding population and clear evidence for genetically isolated populations. The Grenada Dove needs urgent conservation action, including habitat protection and potentially augmentation of gene flow by translocation in order to increase genetic resilience and diversity with the ultimate aim of securing the long-term survival of this Critically Endangered species.