{"title":"In the still of the night: revisiting Eastern Whip-poor-will surveys with passive acoustic monitoring","authors":"Elly C. Knight, Kevin C. Hannah, Jonathan DeMoor","doi":"10.5751/ace-02080-170121","DOIUrl":null,"url":null,"abstract":". Recent advances in passive acoustic monitoring warrant the review of survey protocols because passive acoustic monitoring can increase sampling effort with minimal additional cost. In particular, protocols for nocturnal species should be re-evaluated because automated processing with signal recognition is expected to perform well for these species and surveys conducted by human observers are often limited by safety concerns. We revisited the best survey practices for the Eastern Whip-poor-will ( Antrostomus vociferus ), a nocturnal species of conservation concern. Whip-poor-will surveys are typically limited to nighttime, but also to times of high lunar illumination because their calling rate is associated with moonlight levels. We used automated recognition to extract Whip-poor-will detections from a dataset of autonomous recording unit (ARU) recordings from sites with known Eastern Whip-poor-will occupancy in Ontario, Canada. Temperature and time relative to sunset had particularly strong quadratic effects on detectability, with detectability maximized at 13 °C and 4 hours after sunset. Moon altitude and day of year had positive effects on detectability, while wind speed had negative effects on detectability. We found constraining surveys by optimal values of those detectability covariates was worthwhile only up until 10 recordings, at which point the cumulative probability of detecting an Eastern Whip-poor-will at each site was equal between constrained and unconstrained nocturnal recordings. The number of recordings required to reach an asymptote for detectability was between 81 and 97, depending on recording length. We provide objective-specific recommendations for Eastern Whip-poor-will surveys and suggest unconstrained passive acoustic monitoring as the preferred survey method for many objectives. Given the rise of passive acoustic monitoring, survey practices for many species should be revisited because the increases in sampling effort provided by ARUs can improve cumulative detection probability and potentially outweigh the advantages of limiting surveys to times and dates of optimal detectability. sur la détectabilité, la détectabilité maximale se situant à 13 °C et à 4 heures après le coucher du soleil. L'altitude de la lune et le jour de l'année ont eu des effets positifs sur la détectabilité, tandis que la vitesse du vent a eu des effets négatifs sur celle-ci. Nous avons constaté que le fait de restreindre les relevés aux valeurs optimales de ces covariables de détectabilité ne valait la peine que jusqu'à 10 enregistrements, après quoi la probabilité cumulée de détecter un engoulevent à chaque site était égale entre les enregistrements nocturnes restreints ou non restreints. Le nombre d'enregistrements requis pour atteindre une asymptote de détectabilité se situait entre 81 et 97, selon la longueur de l'enregistrement. Nous offrons des recommandations spécifiques aux objectifs pour les inventaires d'Engoulevent bois-pourri et proposons que le suivi acoustique passif sans restriction soit la méthode d'inventaire privilégiée pour de nombreux objectifs. Étant donné l'essor des suivis acoustiques passifs, les pratiques d'inventaire pour de nombreuses espèces devraient être réévaluées, car l'augmentation de l'effort d'échantillonnage fournie par les EA peut améliorer la probabilité de détection cumulative et l'emporter potentiellement sur les avantages de limiter les inventaires aux heures et aux dates de détectabilité optimale.","PeriodicalId":49233,"journal":{"name":"Avian Conservation and Ecology","volume":"1 1","pages":""},"PeriodicalIF":1.4000,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Avian Conservation and Ecology","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.5751/ace-02080-170121","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}
引用次数: 5
Abstract
. Recent advances in passive acoustic monitoring warrant the review of survey protocols because passive acoustic monitoring can increase sampling effort with minimal additional cost. In particular, protocols for nocturnal species should be re-evaluated because automated processing with signal recognition is expected to perform well for these species and surveys conducted by human observers are often limited by safety concerns. We revisited the best survey practices for the Eastern Whip-poor-will ( Antrostomus vociferus ), a nocturnal species of conservation concern. Whip-poor-will surveys are typically limited to nighttime, but also to times of high lunar illumination because their calling rate is associated with moonlight levels. We used automated recognition to extract Whip-poor-will detections from a dataset of autonomous recording unit (ARU) recordings from sites with known Eastern Whip-poor-will occupancy in Ontario, Canada. Temperature and time relative to sunset had particularly strong quadratic effects on detectability, with detectability maximized at 13 °C and 4 hours after sunset. Moon altitude and day of year had positive effects on detectability, while wind speed had negative effects on detectability. We found constraining surveys by optimal values of those detectability covariates was worthwhile only up until 10 recordings, at which point the cumulative probability of detecting an Eastern Whip-poor-will at each site was equal between constrained and unconstrained nocturnal recordings. The number of recordings required to reach an asymptote for detectability was between 81 and 97, depending on recording length. We provide objective-specific recommendations for Eastern Whip-poor-will surveys and suggest unconstrained passive acoustic monitoring as the preferred survey method for many objectives. Given the rise of passive acoustic monitoring, survey practices for many species should be revisited because the increases in sampling effort provided by ARUs can improve cumulative detection probability and potentially outweigh the advantages of limiting surveys to times and dates of optimal detectability. sur la détectabilité, la détectabilité maximale se situant à 13 °C et à 4 heures après le coucher du soleil. L'altitude de la lune et le jour de l'année ont eu des effets positifs sur la détectabilité, tandis que la vitesse du vent a eu des effets négatifs sur celle-ci. Nous avons constaté que le fait de restreindre les relevés aux valeurs optimales de ces covariables de détectabilité ne valait la peine que jusqu'à 10 enregistrements, après quoi la probabilité cumulée de détecter un engoulevent à chaque site était égale entre les enregistrements nocturnes restreints ou non restreints. Le nombre d'enregistrements requis pour atteindre une asymptote de détectabilité se situait entre 81 et 97, selon la longueur de l'enregistrement. Nous offrons des recommandations spécifiques aux objectifs pour les inventaires d'Engoulevent bois-pourri et proposons que le suivi acoustique passif sans restriction soit la méthode d'inventaire privilégiée pour de nombreux objectifs. Étant donné l'essor des suivis acoustiques passifs, les pratiques d'inventaire pour de nombreuses espèces devraient être réévaluées, car l'augmentation de l'effort d'échantillonnage fournie par les EA peut améliorer la probabilité de détection cumulative et l'emporter potentiellement sur les avantages de limiter les inventaires aux heures et aux dates de détectabilité optimale.
期刊介绍:
Avian Conservation and Ecology is an open-access, fully electronic scientific journal, sponsored by the Society of Canadian Ornithologists and Birds Canada. We publish papers that are scientifically rigorous and relevant to the bird conservation community in a cost-effective electronic approach that makes them freely available to scientists and the public in real-time. ACE is a fully indexed ISSN journal that welcomes contributions from scientists all over the world.
While the name of the journal implies a publication niche of conservation AND ecology, we think the theme of conservation THROUGH ecology provides a better sense of our purpose. As such, we are particularly interested in contributions that use a scientifically sound and rigorous approach to the achievement of avian conservation as revealed through insights into ecological principles and processes. Papers are expected to fall along a continuum of pure conservation and management at one end to more pure ecology at the other but our emphasis will be on those contributions with direct relevance to conservation objectives.