Animal Conservation最新文献

{"title":"Energetics-based connectivity mapping reveals new conservation opportunities for the endangered tiger in Nepal","authors":"N. H. Carter,&nbsp;E. Berti,&nbsp;A. Zuckerwise,&nbsp;N. M. B. Pradhan","doi":"10.1111/acv.12937","DOIUrl":"10.1111/acv.12937","url":null,"abstract":"<p>Enhancing habitat connectivity is a key strategy for conserving endangered species in anthropogenic landscapes. However, connectivity planning often overlooks the crucial energetic costs to animals of traversing complex terrains. We applied a novel approach for estimating energy costs of movement for tigers – a globally endangered species. We used those estimates to calculate landscape connectivity for these animals across the extreme altitudinal gradient of Nepal, where recent sightings of tigers at higher elevations (~3200 m) suggest an upward range expansion from the tiger-rich lowlands. To evaluate our estimates, we simulated tiger routes to higher-elevation locations and compared modeled energy costs of those ascents to those derived from a previous model calibrated with data from GPS-collared tigers in Russia. In areas below 3200 m, we found about 7.5 times greater land areas with high connectivity outside protected areas (~51 000 km²) than inside (~6800 km²). However, most of the highly connected areas below 3200 m consist of croplands (56%). Importantly, community-managed forests, which spanned the altitudinal gradient, tended to include areas with moderate levels of connectivity. Our estimates of energy costs and those from Russia showed a strong consensus (<i>ρ</i> = 0.70, <i>P</i> &lt; 0.05), with ours better capturing the higher energy costs of traversing mountains and of very large total ascents. Our results show that while barriers to tiger movement across Nepal are ubiquitous, other effective area-based conservation measures (OECMs), like community-managed forests, can play prominent roles in promoting tiger habitat connectivity while minimizing human–tiger conflict across anthropogenic landscapes. Our results also underscore the utility of integrating first principles of energy efficiency into connectivity analyses and planning.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 5","pages":"639-647"},"PeriodicalIF":2.8,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12937","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140045957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the need and difficulty of evaluating management strategies improving species persistence","authors":"E. Gaget,&nbsp;T. Galewski,&nbsp;J. E. Brommer,&nbsp;I. Le Viol,&nbsp;F. Jiguet,&nbsp;N. Baccetti,&nbsp;T. Langendoen,&nbsp;B. Molina,&nbsp;F. Moniz,&nbsp;C. Moussy,&nbsp;M. Zenatello,&nbsp;M. Guillemain","doi":"10.1111/acv.12936","DOIUrl":"https://doi.org/10.1111/acv.12936","url":null,"abstract":"","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 1","pages":"21-22"},"PeriodicalIF":3.4,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139993897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Habitat management favouring duck hunting seems to prevent shifting distribution due to climate warming: Another avenue for hunting ‘greenwashing’?","authors":"J. G. Navedo","doi":"10.1111/acv.12934","DOIUrl":"https://doi.org/10.1111/acv.12934","url":null,"abstract":"&lt;p&gt;Habitat management favouring target species has long been proposed as a potential tool to buffer the consequences of natural habitat loss for such species. Furthermore, during the last two decades, several authors have proposed artificial wetland management as a critical tool to mitigate the ongoing effects of climate change on natural habitats for the conservation of waterbirds (wildfowl, shorebirds, herons, etc.) (e.g. Masero, &lt;span&gt;2003&lt;/span&gt;; Green &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2017&lt;/span&gt;). Among them, highly mobile taxa such as migratory waterbird species are declining globally, although with contrasting current trends depending on their geography and phylogeny. For example, duck species are overall experiencing population increases in North America (Rosenberg &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2019&lt;/span&gt;), while they are declining in Europe (Birdlife International, &lt;span&gt;2015&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;In the face of climate change, Gaget &lt;i&gt;et al&lt;/i&gt;. (&lt;span&gt;2023&lt;/span&gt;) recently found that most migratory waterbird populations in Europe (from a total of 110 species evaluated over 28 years at 851 sites) had shifted their non-breeding distribution towards northern areas following ambient temperature increases during this period, with the notable exception of hunted duck populations. Gaget &lt;i&gt;et al&lt;/i&gt;. (&lt;span&gt;2023&lt;/span&gt;) propose that habitat management targeting hunted ducks in southern Europe by providing attractive feeding grounds, which mainly occur in anthropogenic coastal wetlands surrounding the Mediterranean in France and Italy, as the main explanation for this absence of geographical shifting to track improved environmental suitability towards the northern latitudes. They further suggest that ‘habitat management for hunting purposes may hence have counter-balanced the effect of climate warming and ‘retain’ hunting ducks to these wintering grounds, which they would otherwise abandon for more northern areas’ (Gaget &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2023&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;While habitat management for hunting at such specific sites could have partially driven this absence of non-breeding distribution shifting in ducks, regional land-use changes that occur especially in the southern limit of their distribution range in southwestern Europe could have a role. In this light, the creation of several small-scale reservoirs (&lt;1,500 ha) close to rice fields in the mid-Guadiana basin, Extremadura, Spain, during the late 1990s, improved habitat conditions for duck populations that may have resulted in a partial non-breeding redistribution within the Flyway (Navedo &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2012&lt;/span&gt;). Therefore, if such reservoir creation in nearby rice fields overall improved habitat conditions for duck populations, this could alternatively explain the lack of distribution shifting reported by Gaget &lt;i&gt;et al&lt;/i&gt;. (&lt;span&gt;2023&lt;/span&gt;) but would support their broader point: habitat management can influence winter distributions of waterbirds.&lt;/p&gt;&lt;p&gt;Among specific long-term consequences of this","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 1","pages":"19-20"},"PeriodicalIF":3.4,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12934","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139993927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disentangling the complexity of climate change and land-management effects on wildlife communities","authors":"A. Santangeli","doi":"10.1111/acv.12923","DOIUrl":"https://doi.org/10.1111/acv.12923","url":null,"abstract":"&lt;p&gt;As the climate is changing, wildlife species and communities often shift towards high latitudes, among other possible responses (Pecl &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2017&lt;/span&gt;). However, such climate-driven latitudinal shifts are often mediated, hindered or facilitated, by other forces. Such forces materialize at different scales, from regional to continental level, such as ecological barriers (Marjakangas &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2023&lt;/span&gt;), to local scale, such as land-use and habitat management (e.g. Thomas &amp; Gillingham, &lt;span&gt;2015&lt;/span&gt;). The study by Gaget &lt;i&gt;et al&lt;/i&gt;. (&lt;span&gt;2023&lt;/span&gt;) uses a long-term dataset from non-breeding water bird surveys to answer a topical question: Under climate change, do distribution shifts of hunted duck species differ from those of non-hunted (and other hunted) species? The prediction was that local-scale hunting habitat management would increase the site fidelity of hunted species, thereby hindering their climate-driven latitudinal shift as compared to non-hunted species. The authors apply a widely used community-level approach (Devictor &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2008&lt;/span&gt;) to quantify the overall response to climate change. The approach is based on combining site-level survey data with species-specific temperature index (i.e. the average long-term temperature experienced by the species across its range) to derive a community-weighted mean thermal affinity (i.e. an index representing the balance between warm and cold-dwelling species; Devictor &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2008&lt;/span&gt;). The authors are then able to trace the individual contribution of each species to the community shift and relate this contribution to species-level traits. While the broad pattern of community-level shift following climate change has been widely demonstrated, this research is the first to reveal that hunted duck species appear to be less inclined to shift their distribution in response to climate warming compared with non-hunted species (Gaget &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2023&lt;/span&gt;). This highlights the broad potential impacts of anthropogenic interventions on wildlife communities which may not only facilitate shifts under climate change, but also hinder them. Hunting habitat management, often based on managing habitat to increase the food base for plant-eating waterbirds, is thought to be rather common in the study region, South-Western Europe. This intervention may boost winter site fidelity for waterbirds, thereby explaining the pattern found. Indeed, rather convincingly, all of the hunted plant-eating species considered in this study had a negative contribution towards the overall community shift (Gaget &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2023&lt;/span&gt;). That is, they hinder the community adjustment to climate change.&lt;/p&gt;&lt;p&gt;This research provides two main pointers for discussion regarding future applied research lines, with wide implications for biodiversity conservation under global change. Firstly, it indicates the potential effects of a persistence stra","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 1","pages":"17-18"},"PeriodicalIF":3.4,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12923","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139993901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the role of caretaker-rated personality traits for reproductive outcomes in a highly endangered Hawaiian corvid","authors":"A. M. Flanagan,&nbsp;M. B. Petelle,&nbsp;A. L. Greggor,&nbsp;B. Masuda,&nbsp;R. R. Swaisgood","doi":"10.1111/acv.12931","DOIUrl":"10.1111/acv.12931","url":null,"abstract":"<p>Personality studies are increasingly relevant and applicable to a broad range of conservation issues, including a role for selecting compatible mates in conservation breeding programs (CBPs). Choosing compatible breeding pairs is essential for maximizing reproductive success in CBPs, which provide assurance populations for species facing extinction and candidates for translocation to support wild populations. We investigated the value of caretaker-assessed personality ratings of the critically endangered ‘Alalā (Hawaiian Crow, <i>Corvus hawaiiensis</i>) in predicting reproductive outcomes: nest quality, fertile egg production, and hatchability in the ‘Alalā CBP. Caretakers used well-defined operational definitions to rate 22 personality traits for 69 male and 59 female ‘Alalā, achieving high inter-rater agreement (ICC ≥ 0.85) for 8 traits – aggressive, bold/fearless, fearful, imprinted/abnormal, inept, submissive, territorial, and tendency to feather pluck (a stereotypic behavior) – used in a principal components analysis to distill intercorrelated variables into three principal components. While we did not find that personality influences nest quality or hatchability (based on limiting inferences to fixed effects with high relative importance scores; ≥0.8), we found some evidence that pairs with males that were more territorial/aggressive and fearful than their mates had a higher probability of egg fertilization, but there was substantial variability in this relationship, with confidence intervals overlapping zero. These personality traits may influence pair dynamics, enhancing compatibility, may predict better pair coordination on the nest, or both. Our results highlight the ability of caretakers to successfully identify ‘Alalā personality traits and provide some support for integrating personality into the pairing process; however, further research is needed to understand the value of ‘Alalā personality as a mate selection tool. The application of similar approaches to enhance CBP performance in other taxa is promising, but will require overcoming methodological challenges surrounding the complexity of data collection and interpretation of consistency among raters.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"554-565"},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139678103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perceptions and reality in fisher coexistence with aquatic predators in the Peruvian Amazon","authors":"M. Recharte,&nbsp;P. Lee,&nbsp;D. Meza,&nbsp;S.-J. Vick,&nbsp;M. Bowler","doi":"10.1111/acv.12932","DOIUrl":"10.1111/acv.12932","url":null,"abstract":"<p>Humans and large aquatic predators compete for fish and negative interactions are widely reported as ‘human–wildlife conflicts’. When aquatic predators are perceived to damage fisheries or fishing equipment, lethal control can occur. The perceptions and reality of damage are infrequently compared, but this relationship is key to determining how negative outcomes can be mitigated. We examine coexistence between people and six large aquatic piscivores (two caiman, two dolphins, two otters) in Amazonian Peru. We determine the extent of damage to fishing equipment caused by each species and compare this to the amount of damage perceived by fishers. Giant otter populations have recently recovered in some areas, so we expected different perceptions relating to experiences with otters. We trained fishers to complete fishing registers (<i>n</i> = 278, 1173 h of fishing) to record damage to nets by wildlife. We interviewed 302 people from three sites to determine perceptions of damage by predators, and attitudes towards giant otters. Rates of damage to nets reflected the presence and populations of different aquatic predators at each site, but when present, dolphins and caimans damaged nets more than otters, which rarely damaged nets. People living where giant otters had recently recovered perceived higher relative levels of damage to nets by them and had more negative attitudes about them, compared to people from areas where giant otters had been present for longer, aquatic predators were more abundant, and community resource management was longer-established. Better knowledge and more experience with a species may lead to more accurate perceptions of damage and increased tolerance. Where humans and animals compete for natural resources, conflict mitigation rarely includes better resource management. If tolerance of predators is greater where predators are common, and resources have not been overexploited, resource management may yield greater gains for stakeholders than other commonly prescribed forms of mitigation.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"566-579"},"PeriodicalIF":2.8,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12932","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139552855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unravelling unique responses of mammal abundance to road proximity in agricultural landscapes","authors":"V. Alberici,&nbsp;A. L. J. Desbiez,&nbsp;N. Pasqualotto,&nbsp;A. G. Chiarello","doi":"10.1111/acv.12933","DOIUrl":"10.1111/acv.12933","url":null,"abstract":"<p>Roads can impact population abundance due to mortality from collisions with vehicles, habitat degradation and loss of connectivity. Some species, however, can be unaffected or even positively affected by roads and roadside environments. Despite this, there is scarce information on population-level responses to roads. To fill this knowledge gap, we sampled medium and large mammals with camera traps near two paved roads with low and high traffic volumes in agricultural landscapes in the Brazilian Cerrado. We used Royle-Nichols' occupancy models to investigate the effects of road proximity on the local abundance of 12 mammal species with varying susceptibility to roadkill. We found that road proximity affected only three species, all of which had high roadkill rates. While two of these species exhibited lower abundance near roads, the third showed the opposite response. For most species, irrespective of their roadkill rates, variations in local abundance were strongly correlated with habitat quality and connectivity. Species' life-history traits, individual behaviour and the impact of roads and traffic on populations over time may explain these idiosyncratic responses.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 5","pages":"611-625"},"PeriodicalIF":2.8,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139553194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multiscale perspective for improving conservation of Conchos pupfish","authors":"L. C. Elkins,&nbsp;M. R. Acre,&nbsp;M. G. Bean,&nbsp;S. M. Robertson,&nbsp;R. Smith,&nbsp;J. S. Perkin","doi":"10.1111/acv.12930","DOIUrl":"10.1111/acv.12930","url":null,"abstract":"<p>Desert spring systems of the American southwest hold high local fish endemism and are ranked among the most threatened ecosystems in the world. The prioritization of conservation resources to protect species living within these arid landscapes requires knowledge of species abundance and distribution. The plight of Conchos pupfish (<i>Cyprinodon eximius</i>) is representative of freshwater fishes the world over, including population extirpations caused by human poisoning of streams and reservoir construction, to the extent that the species was once considered extinct in the USA. We developed a distance-sampling framework to monitor Conchos pupfish abundance and coupled this approach with species distribution modeling to guide conservation actions. Our multiscale approach included surveying abundances within 5-m transects at three reaches of the Devils River, where the last known USA populations persist. We combined this fine-scale analysis with species distribution modeling for stream segments across the range of the species in Mexico and USA. Modeling revealed Conchos pupfish abundance among transects was negatively correlated with current velocity and detection was negatively correlated with water depth. Estimated abundance at a reach where the species was previously reintroduced was greater than other reaches combined in November 2019, lowest in March 2021 when reach water levels were very low, then equivalent with other reaches by October 2021 after water returned to the reach. Modeled Conchos pupfish distribution illustrated a high probability of occurrence on the periphery of the species' overall range within Texas, USA and broadly across Chihuahua, Mexico, where proposed protected areas might benefit the species. Our study provides conservation guidance by establishing (1) baseline and trajectory values for abundance, (2) transect locations where abundances might be managed within existing protected areas, (3) reaches where high abundances could be used for future repatriation, and (4) stream segments where future surveys might be conducted to assess conservation opportunities.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"538-553"},"PeriodicalIF":2.8,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12930","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139552772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of forest fragmentation and associated edge effects on the population density of four nocturnal lemur species in North West Madagascar","authors":"D. Hending,&nbsp;H. Randrianarison,&nbsp;N. N. M. Andriamavosoloarisoa,&nbsp;C. Ranohatra-Hending,&nbsp;G. McCabe,&nbsp;S. Cotton,&nbsp;M. Holderied","doi":"10.1111/acv.12929","DOIUrl":"10.1111/acv.12929","url":null,"abstract":"<p>The clearing and fragmentation of tropical forests is the single biggest threat to primate populations who depend on this habitat for survival. In contrast to primates that live in continuous, undisturbed forests, primate communities of fragmented forests need to adapt to decreased food availability and increased inter- and intraspecific competition typical of these degraded and anthropogenically disturbed habitats. Some primate species are highly sensitive to habitat fragmentation, whilst other species can adapt and even thrive in fragmented and degraded forests. Here, we assessed how forest fragmentation and associated edge effects impact the population density of four species of nocturnal lemur in the Sahamalaza-Iles Radama National Park, North West Madagascar. We conducted 118 transect walks over a 3-year period covering a total distance of 107 km to collect encounter rate (<i>N</i>/km) and population density (<i>N</i>/Ha) data for each species, which we then compared between the edge and core areas of a continuous forest and a fragmented forest. Our results were highly species-specific, with the population densities of two species (<i>Lepilemur sahamalaza</i> and <i>Microcebus sambiranensis</i>) increasing in edge and fragmented habitat, whilst we observed the opposite for <i>Cheirogaleus medius</i>. <i>Mirza zaza</i> density appeared consistent between the continuous and fragmented forest and in both edge and core areas. We also found evidence of species-specific population density relationships with fragment size, core area and fragment shape; however, further work is needed to support these findings. This study demonstrates that some nocturnal lemurs can adapt to degraded habitats and thrive within fragmented forests, whilst other species are less capable of doing so.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"522-537"},"PeriodicalIF":2.8,"publicationDate":"2024-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12929","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139516950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating abundance of a small population of Bryde's whales: a comparison between aerial surveys and boat-based platforms of opportunity","authors":"O. N. P. Hamilton,&nbsp;R. M. Fewster,&nbsp;P. Low,&nbsp;F. Johnson,&nbsp;C. Lea,&nbsp;K. A. Stockin,&nbsp;K. van der Linde,&nbsp;R. Constantine","doi":"10.1111/acv.12928","DOIUrl":"10.1111/acv.12928","url":null,"abstract":"<p>Accurate abundance estimates are essential for the development of effective conservation management strategies, yet they are difficult to produce for small populations that are elusive and sparsely distributed throughout their range. For such populations it is challenging to collect a representative dataset sufficient for robust estimation of detectability and abundance. Over a one-year study, we used two methods to estimate abundance of a Nationally Critical, widely dispersed Bryde's whale population in the Hauraki Gulf, Aotearoa/New Zealand; (i) distance sampling from systematic line-transect aerial surveys (<i>n</i> = 22 surveys, 9,944 km, total sightings 21–24 whales), and (ii) mark-recapture (MR) using photo-identification images collected from a platform-of-opportunity and small-boat surveys (218 sampling occasions, 27 whales). From the aerial surveys, we estimated an average of 15 whales (95% CI = 6, 30; CV = 37%) at the sea-surface at any time. For the boat-based surveys, we developed a custom MR model to address seasonal and individual heterogeneity in capture probabilities and obtained an estimate of 72 distinct whales (95% CI = 38, 106; CV = 24%) in the population. These two approaches provide different perspectives on the abundance and dynamics of Bryde's whales. The aerial surveys estimate the average number of individuals present at any one time, whereas the MR model estimates the total number of animals that used the Gulf during the study. Although neither sampling method is optimal for estimating the abundance of this small, dispersed population, the use of two complementary approaches informs conservation managers about patterns of abundance and distribution over different temporal and spatial scales. It is common to have limited resources for marine research where model assumptions cannot be met. Here, we highlight pragmatic strategies showing how models can be customized to the population of interest to assist with monitoring species of conservation concern.</p>","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"426-436"},"PeriodicalIF":2.8,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12928","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}