Automated signal recognition software is increasingly used to extract species detection data from acoustic recordings collected using autonomous recording units (ARUs), but there is little practical guidance available for ecologists on the application of this technology. Performance evaluation is an important part of employing automated acoustic recognition technology because the resulting data quality can vary with a variety of factors. We reviewed the bioacoustic literature to summarize performance evaluation and found little consistency in evaluation, metrics employed, or terminology used. We also found that few studies examined how score threshold, i.e., cutoff for the level of confidence in target species classification, affected performance, but those that did showed a strong impact of score threshold on performance. We used the lessons learned from our literature review and best practices from the field of machine learning to evaluate the performance of five readily-available automated signal recognition programs. We used the Common Nighthawk (Chordeiles minor) as our model species because it has simple, consistent, and frequent vocalizations. We found that automated signal recognition was effective for determining Common Nighthawk presence-absence and call rate, particularly at low score thresholds, but that occupancy estimates from the data processed with recognizers were consistently lower than from data generated by human listening and became unstable at high score thresholds. Of the five programs evaluated, our convolutional neural network (CNN) recognizer performed best, with recognizers built in Song Scope and MonitoR also performing well. The RavenPro and Kaleidoscope recognizers were moderately effective, but produced more false positives than the other recognizers. Finally, we synthesized six general recommendations for ecologists who employ automated signal recognition software, including what to use as a test benchmark, how to incorporate score threshold, what metrics to use, and how to evaluate efficiency. Future studies should consider our recommendations to build a body of literature on the effectiveness of this technology for avian research and monitoring. Recommandations pour l'évaluation des performances de reconnaissance acoustique et application à cinq programmes courants de reconnaissance automatisée de signaux sonores RÉSUMÉ. Les logiciels de reconnaissance automatisée de signaux sonores sont de plus en plus utilisés pour extraire les données de détection des espèces d'enregistrements acoustiques récoltés au moyen d'unités d'enregistrement autonomes (ARU en anglais), mais il existe peu d'instructions pratiques sur l'utilisation de cette technologie pour les écologistes. L'évaluation de la performance est une étape importante dans l'utilisation d'une technologie de reconnaissance acoustique automatisée parce que la qualité des résultats peut varier en fonction de divers facteurs. Nous avons passé en revue la littérature sur la bioacoustique afin de résumer les critères d'évaluation de ...

Research666 the probability that our method missed peaks (spatial: 0.12, temporal: 0.18) or detected false peaks (spatial: 0.11, temporal: 0.37) due to data gaps and showed that our approach remains useful even for sparse and/or sporadic location data. Our study presents a generalizable approach to evaluating migratory connectivity across the full annual cycle that can be used to focus migratory bird conservation towards places and times of the annual cycle where populations are more likely to be limited.

Agricultural expansion and intensification are some of the leading drivers of biodiversity loss globally. Effective conservation and management strategies for threatened species in agroecosystems require information on how these species are affected by (1) the amount and configuration of natural habitats, and (2) the type and extent of agricultural land covers. The Eastern Whippoor-will (Caprimulgus vociferous) and Common Nighthawk (Chordeiles minor) are two nocturnal aerial insectivores in decline in North America, and have breeding ranges that include agriculturally dominated landscapes. We first assessed mean breeding occupancy of both species in eastern Ontario, Canada in 2016 using acoustic recording units at 127 sites. We then assessed the effects of landscape composition (forest, agriculture, wetlands, and urban covers), forest configuration (mean patch size, number of patches, distance to nearest patch), and agriculture type (perennial forages versus cropland) on Eastern Whip-poor-will occupancy. Eastern Whip-poorwill and Common Nighthawk occupancy in the study area averaged 0.244 and 0.064, respectively. We were unable to examine the relationships between landscape composition/configuration and Common Nighthawk occupancy because of small sample sizes. Nonetheless, Eastern Whip-poor-will occupancy was positively correlated with the amount of wetland cover and forest patch size, was weakly negatively correlated with urban land cover, and was unrelated to the type of agriculture. Our results highlight how the conservation of the Eastern Whip-poor-will in agricultural landscapes of eastern Canada would benefit from both wetland protection and the presence of larger forest patches, which can be accomplished through both forest protection and by allowing forest regeneration on abandoned lands.Les effets de la composition et de la configuration du paysage sur la présence de l'Engoulevent boispourri (Caprimulgus vociferous) et de l'Engoulevent d'Amérique (Chordeiles minor) dans un agroécosystème RÉSUMÉ. L'expansion et l'intensification de l'agriculture sont parmi les causes principales de perte de biodiversité à l'échelle mondiale. Pour que les stratégies de conservation et de gestion des espèces menacées vivant dans les agroécosystèmes soient efficaces, il est important de savoir comment ces espèces sont affectées par (1) la superficie et la configuration des milieux naturels, et (2) le type et l'étendue des terres agricoles. L'Engoulevent bois-pourri (Caprimulgus vociferous) et l'Engoulevent d'Amérique (Chordeiles minor) sont deux insectivores aériens nocturnes en diminution en Amérique du Nord, et leur aire de nidification comprend des paysages dominés par l'agriculture. Premièrement, nous avons déterminé la présence de ces deux espèces au moment de la nidification dans l'est de l'Ontario, Canada, à l'aide d'enregistreurs automatiques à 127 sites en 2016. Nous avons ensuite évalué les effets de la composition du paysage (couvert forestier, agricole, de milieux humides ou urbain), de la configuration forestièr...

No abstract

The Northern Hawk Owl (Surnia ulula) remains one of the least-studied birds in North America. Although hawk owls use burned forest, reports of this association have been primarily anecdotal and outside the breeding season. We present the first comparison of hawk owl relative abundance between burned and unburned conifer-dominated boreal forest in North America. Hawk owls were detected only in postfire forest and were not detected in nearby unburned coniferous forest. There was a significant negative exponential relationship between hawk owl abundance and burn age, suggesting that burns were only suitable up to 8 years post- fire. A conservative estimate of a peak in breeding density was three nests per 100 km2 for a 2-year-postfire forest. Wildfire and newly burned forests may be an important feature for hawk owls in the Nearctic boreal forest. This raises the question whether management of this species through improved forestry techniques is a sufficient conservation measure. Surnia ulula y Fuegos Recientes: ¿Es la Edad de la Quema Importante? Resumen. El búho Surnia ulula es una de las aves de Norte América que ha sido menos estudiada. Aunque estos búhos utilizan bosques quemados, los reportes de esta asociación han sido principalmente anecdóticos y han tenido lugar fuera de la época reproductiva. En este estudio presentamos la primera comparación de la abundancia relativa de S. ulula entre ambientes quemados y no quemados en bosques boreales de Norte América dominados por coníferas. Los búhos fueron detectados únicamente en bosques quemados y no se encontraron en bosques de coníferas cercanos que no habían sido quemados. Existió una relación exponencial negativa significativa entre la abundancia de S. ulula y la edad de las quemas, lo que sugiere que los bosques quemados sólo fueron adecuados para la especie hasta ocho años después del fuego. Una estimación conservadora del pico en la densidad reproductiva fue de tres nidos por 100 km2 para un bosque luego de dos años de ser quemado. Los fuegos naturales y los bosques recientemente quemados podrían ser importantes para S. ulula en los bosques boreales Neárticos. Esto lleva a considerar si el manejo de esta especie a través de técnicas forestales mejoradas es una medida de conservación suficiente.