Tail pattern variation in the Black Wheatear (Oenanthe leucura)

“This is a post-peer-review, pre-copyedit version of an article published in Journal of Ornithology. The final authenticated version is available online at: https://doi.org/10.1007/s10336-017-1524-x"Delayed plumage maturation occurs in birds when subadult plumage is retained until after the frst breeding season. We analysed data from 114 Black Wheatears (Oenanthe leucura), which were trapped during 2014–2016 in southeastern Spain, to explore whether biometric measurements, and more specifcally tail pattern, difered among age and sex classes, and whether there was a relationship between tail pattern and delayed plumage maturation. Males and adults were heavier and had longer wings and tails than females and juveniles, respectively. Adult birds had longer terminal black tail bars than juveniles, which suggests a potential dominance-signalling function for the tail pattern. Further research is needed to investigate the relationship between these traits and sexual selection and dominance in Black WheatearJS works within the Madrid’s Government research group network REMEDINAL3-CM (S-2013/MAE-2719

Extensive sheep grazing is associated with trends in steppe birds in Spain: recommendations for the Common Agricultural Policy

Iberian natural steppes have traditionally been used for extensive sheep grazing, which has been noted to be positively associated with steppe bird abundance and diversity. Sheep numbers in Spain, which harbors the largest European populations of many steppe bird species, decreased by 9.2 million (37.3%) between 1992 and 2020. Steppe birds in Spain have faced dramatic declines during the same period, but there is a lack of knowledge about the potential association between sheep and open-habitat bird declines. We used sheep data from the Spanish Ministry of Agriculture and bird data (1998–2018) from the Spanish Common Bird Monitoring Program to assess the association at the Spanish scale between sheep decline and the Farmland Bird Index (FBI) and the Natural Shrub-steppe Bird Index (SBI). We also used an independent dataset on population trends of the Dupont’s Lark (Chersophilus duponti) to assess the relationship between sheep numbers and the decline of this threatened steppe specialist passerine in Spain, whose European population is restricted to Iberian natural steppes. To test for a spurious relationship between temporal series, variables were tested for cointegration. After confirming cointegration, we found a strong positive relationship between sheep abundance and the trends of the FBI and SBI indices during the period 1998–2018. The association between sheep abundance and trends of the Dupont’s Lark (2004–2015) was positive although it was not statistically significant. Although the main causes of decline of farmland and steppe birds are mainly related to agricultural intensification and land use changes, the correlation found, using two independent cointegrated datasets, between the reduction in farmland and shrub-steppe birds and sheep numbers at the country scale suggests that the decline of steppe birds in Spain may be also associated with the decline in sheep numbers. This agrees with previous studies that found a positive relationship between intermediate levels of sheep grazing and steppe bird abundance in Iberian steppes. Further research (e.g. experimental studies) is needed to corroborate our study and identify the most appropriate level of grazing intensity for protecting the most farmland and shrub-steppe birds. Our results suggest that the promotion of extensive grazing should be considered as a key factor in future Common Agricultural Policy reforms and conservation programmes to protect steppe birds.This is a contribution to the Excellence Network Remedinal 3CM (S2013/MAE2719), supported by Comunidad de Madrid and to the LIFE Ricotí (ES-LIFE15/NAT/ES/000802) and LIFE Connect Ricotí (ES-LIFE20/NAT/ES/000133) projects, supported by the European Commission

The sound of the illegal: Applying bioacoustics for long-term monitoring of illegal cattle in protected areas

Passive acoustic monitoring coupled with automated signal recognition software has been widely used in recent years as an effective and affordable tool for wildlife monitoring and to combat illegal activities within protected areas. Here, we evaluate this technique to monitor the patterns of illegal cattle occurrence in the Brazilian Pantanal over a complete annual cycle. We aim to provide one of the first assessments of the performance of automated signal recognition software to detect ungulates. Cattle occurrences reached their maximum during the end of the dry season when lowland areas provide excellent pastures for cattle. In contrast, cattle occurrences were very low during the rainy season when the study area was seasonally inundated. Automated software was an efficient tool that was able to detect approximately three-quarters of cow calls within the recordings. Passive acoustic monitoring can be used to direct patrols to areas where illegal activities, such as cattle and poaching or logging, have been confirmed, which could be a method that would be especially well suited for remote areas, such as tropical forests. Future studies should evaluate whether there is a relationship between cattle grazing intensity and its associated impacts on wildlife and flora. Rapid advances in automated recognition and the recent development of low-cost recorders foresee a new era of acoustic ecology for improved conservation in the short term.This study is part of the biodiversity monitoring project Sounds of the Pantanal - The Pantanal Automated Acoustic Biodiversity Monitoring of INAU/CO.BRA, Cuiabá, Mato Grosso, Brazil, which was conducted under SISBIO permit no. 39095 (KLS). We greatly appreciate the financial support provided by the following institutions: the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil (CAPES), Finance Code 01; Instituto Nacional de Ciência e Tecnologia em Áreas Úmidas (INAU/UFMT/CNPq); Centro de Pesquisa do Pantanal (CPP); and Brehm Funds for International Bird Conservation (BF), Bonn, Germany

Passive Acoustic Monitoring of Chaco Chachalaca (Ortalis canicollis) Over a Year: Vocal Activity Pattern and Monitoring Recommendations

Chaco Chachalaca (Ortalis canicollis) is a declining Neotropical bird, for which our current knowledge about its natural history is very limited. Here, we evaluated for first time the utility of passive acoustic monitoring, coupled with automated signal recognition software, to monitor the Chaco Chachalaca, described the vocal behavior of the species across the diel and seasonal cycle patterns, and proposed an acoustic monitoring protocol to minimize error in the estimation of the vocal activity rate. We recorded over a complete annual cycle at three sites in the Brazilian Pantanal. The species was detected on 99% of the monitoring days, proving that this technique is a reliable method for detecting the presence of the species. Chaco Chachalaca was vocally active throughout the day and night, but its diel activity pattern peaked between 0500 and 0900. The breeding season of Chaco Chachalaca in the Brazilian Pantanal, based on seasonal changes in vocal activity, seems to occur during the last months of the dry season, with a peak in vocal activity between August and October. Our results could guide future surveys aiming to detect the presence of the species, both using traditional or acoustic surveys, or to evaluate changes in population abundance using passive acoustic monitoring, for which recorders should be left in the field for a minimum period of nine days to obtain a low-error estimate of the vocal activity of the species. Our results suggest that passive acoustic monitoring might be useful, as a complementary tool to field studies, for monitoring other cracids, a family with several threatened species that are reluctant to human presence.We greatly appreciate the financial support from the following institutions: the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil (CAPES), Finance Code 01; Instituto Nacional de Ciência e Tecnologia em Áreas Úmidas (INAU/UFMT/CNPq); Centro de Pesquisa do Pantanal (CPP); and Brehm Funds for International Bird Conservation (BF), Bonn, Germany

Automated signal recognition as a useful tool for monitoring little-studied species: The case of the Band-tailed Nighthawk

Passive acoustic monitoring, when coupled with automated signal recognition software, is a useful technique for monitoring vocally active taxa. In this study, we evaluated the utility of automated signal recognition to gain insights into the ecology of little-studied species. For this purpose, we selected an avian family, Caprimulgidae (nightjars), composed of cryptic and nocturnal species, and focused the study on a Neotropical wetland, the Brazilian Pantanal. We reviewed the number of publications, observations, and recordings available for each nightjar inhabiting the Brazilian Pantanal and the Band-tailed Nighthawk (Nyctiprogne leucopyga) was identified as the species with the least information available. We employed automated signal recognition software to study the vocal behavior of this species over a complete annual cycle in the Pantanal. Previous knowledge about the ecology of this species is based on general descriptions and anecdotal observations. Our findings corroborate that the Nighthawk is a resident species of the Brazilian nightjars, and according to seasonal changes in vocal activity, the breeding season extends from July to October. The breeding period starts at the end of the dry season (July–August), and the nesting period may occur at the beginning of the wet season and following the first rains, which is a period of maximum insect food availability. The vocal activity of the Nighthawk was restricted to the nocturnal period and was maximum at dusk. That preference for dusk is in disagreement with the pattern described for the other four nightjars in the study area, which highlights the importance of performing species-specific studies and avoiding drawing any conclusions about the activity pattern of a species based on the genus or family to which it belongs to. Automated signal recognition software was able to detect over three quarters of the songs annotated by a human on a subset of sound recordings, therefore proving its utility for monitoring the Band-tailed Nighthawk.We greatly appreciate financial support from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil (CAPES), Finance Code 01; Instituto Nacional de Ciência e Tecnologia em Áreas Úmidas (INAU/UFMT/CNPq); Centro de Pesquisa do Pantanal (CPP); and Brehm Funds for International Bird Conservation (BF), Bonn, Germany

Diel and seasonal variation of Striped Cuckoo (Tapera naevia) vocalizations revealed using automated signal recognition

Studying seasonal changes in the vocal activity of birds may shed light on the function of avian vocalizations and the phenology of life history events. Our current knowledge regarding the seasonality of the vocal behaviour of tropical birds in general, and avian brood parasites in particular, is very limited. Here, we employed passive acoustic monitoring with automated signal recognition to monitor the vocal behaviour of the Striped Cuckoo Tapera naevia over a complete annual cycle in the Brazilian Pantanal. We evaluated whether the pattern of vocal activity differed between the two main vocalizations of the species (sem-fim and wee-series songs) and whether vocal activity varied with time of day and season. The diel pattern of vocal activity for both vocalization types showed a bimodal pattern, with the first peak of vocal activity in the few hours after sunrise and the second peak before sunset, in agreement with prior studies in other cuckoos. The sem-fim song was also produced during the night, while the wee-series song was produced only during the day. Both vocalization types showed clear seasonality and were produced between mid-June and mid-February. Seasonal changes in vocal activity suggest that the Striped Cuckoo breeds during the dry season and leaves the study area during the flooding period. The seasonal pattern of the wee-series song showed strong seasonality, with 90% of these calls detected in September and October, whereas the sem-fim song showed weaker seasonality, with 80% of the calls detected during the July–October period. Our study indicates that automated signal recognition might be a reliable tool for monitoring cuckoos. Further research could evaluate whether the different seasonal patterns of the sem-fim and wee-series songs of the Striped Cuckoo are related to different functions.We greatly appreciate financial support from: the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil (CAPES), Finance Code 01; Instituto Nacional de Ciência e Tecnologia em Áreas Úmidas (INAU/UFMT/CNPq); Centro de Pesquisa do Pantanal (CPP); and Brehm Funds for International Bird Conservation (BF), Bonn, Germany. Furthermore, we thank the SESC Pantanal, Mato Grosso, for permission to conduct research on their property and their logistical help with our fieldwork. C.P.G. acknowledges support from Ministerio de Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo – Convocatoria 2020)

Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, daily rainfall was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.This research was funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil (CAPES), Finance Code 01; Instituto Nacional de Ciência e Tecnologia em Áreas Úmidas (INAU/UFMT/CNPq); Centro de Pesquisa do Pantanal (CPP); and Brehm Funds for International Bird Conservation (BF), Bonn, Germany

A wintering waterbird community in an artificial wetland: Laguna de Meco

[EN]: The progressive loss of natural wetlands throughout Europe has led to the use of human infrastructures such as gravel pits, irrigation ponds and reservoirs by waterbirds as an alternative habitat. In Central Spain, the presence of man-made wetlands is essential for waterfowl conservation. The temporal dynamics of the wintering waterbird community was studied in an artificial wetland located in Madrid, Central Spain (Laguna de Meco). We carried out fortnightly censuses between October 2011 and February 2012 (total of 10) to describe variations in patterns of abundance and of species and taxonomic group richness. A total of 27 aquatic species and 2,901 birds were recorded. Diversity, number of birds and species richness varied between months. The highest numbers of birds occurred in October and February, while the greatest diversity and species richness were recorded during the postnuptial migration in October and November due to the large number of shorebirds occurring in those months. The most abundant species over the study period was the Common Coot Fulica atra, with 38% of the total birds counted, the only exception being the last half of February when the Black-headed Gull Chroicocephalus ridibundus was commonest. Despite only having been created in 2008, this lagoon hosts one of the most important waterfowl communities in Madrid and plays a crucial role in shorebird migration and waterbird conservation in the area. The information provided here could be useful for management strategies in this artificial wetland, which include protecting the lagoon and discarding the idea of moving it to a nearby area.[CA]: La pèrdua progressiva de zones humides naturals fa que les aus aquàtiques facin servir cada cop més, com a hàbitats alternatius, infraestructures humanes, com graveres, basses de reg o embassaments. Al centre d’Espanya, la presència de zones humides d’origen humà és fonamental per a la conservació de les aus aquàtiques. Es va estudiar la dinàmica temporal de la comunitat d’aus aquàtiques hivernants en un aiguamoll artificial de Madrid, la llacuna de Meco. Es van dur a terme deu censos quinzenals entre octubre de 2011 i febrer de 2012 amb l’objectiu de descriure el patró de variació temporal en l’abundància i riquesa de les espècies i grups taxonòmics. Es van detectar un total de 102 espècies, 27 de les quals eren aquàtiques, amb un total de 2.901 aus censades. La diversitat, el nombre d’aus i la riquesa d’espècies va variar entre mesos. Els valors més alts d’abundància d’individus es van obtenir a l’octubre i febrer, mentre que la major diversitat i riquesa d’espècies es van donar durant la migració postnupcial a l’octubre i novembre, a causa del gran nombre de limícoles presents en aquells mesos. L’espècie més abundant durant tot el període d’estudi va ser la Fotja Vulgar Fulica atra, que va suposar el 38% total dels individus censats, exceptuant la segona meitat de febrer durant la qual l’espècie més abundant va ser la Gavina Vulgar Chroicocephalus ridibundus. La llacuna de Meco, en només quatre anys des de la seva creació, ha estat capaç d’albergar una de les comunitats d’aus aquàtiques més importants de Madrid. La presència i estructura d’aquesta llacuna juga un paper clau per a les limícoles en migració i per a la conservació de les aus aquàtiques a la regió. Els resultats d’aquest estudi proporcionen informació útil per a la gestió d’aquesta zona humida artificial, com la seva protecció en lloc de la seva translocació a una zona propera a causa de l’ampliació de les infraestructures que l’envolten.[ES]: La pérdida progresiva de humedales naturales ha hecho que las aves acuáticas usen cada vez más, como hábitats alternativos, infraestructuras humanas, tales como graveras, balsas de riego o embalses. En el centro de España, la presencia de humedales de origen humano es fundamental para la conservación de las aves acuáticas. Se estudió la dinámica temporal de la comunidad de aves acuáticas invernantes en un humedal artificial de Madrid, la laguna de Meco. Se llevaron a cabo diez censos quincenales entre octubre de 2011 y febrero de 2012, con objeto de describir el patrón de variación temporal en la abundancia y riqueza de las especies y grupos taxonómicos. Se registraron un total de 102 especies, 27 de ellas acuáticas, con un total de 2.901 aves censadas. Los valores más altos de abundancia de individuos se obtuvieron en octubre y febrero, mientras que la mayor diversidad y riqueza de especies se dieron durante la migración postnupcial en octubre y noviembre, debido al gran número de limícolas presentes en aquellos meses. La especie más abundante durante todo el periodo de estudio fue la Focha Común Fulica atra, que supuso el 38% total de los individuos censados, exceptuando la segunda mitad de febrero en que la especie más abundante fue la Gaviota Reidora Chroicocephalus ridibundus. La laguna de Meco, en tan solo cuatro años de existencia, ha sido capaz de albergar una de las comunidades de aves acuáticas más importantes de Madrid. La presencia y estructura de esta laguna juega un papel clave para las limícolas en migración y para la conservación de las aves acuáticas en la región. Los resultados de este estudio proporcionan información útil para la gestión de este humedal, como su protección en vez de la translocación a una zona cercana debido a la ampliación de las infraestructuras que la rodean.Peer Reviewe

Passive acoustic monitoring for estimating human-wildlife conflicts: The case of bee-eaters and apiculture

In human-wildlife conflicts, it is crucial to develop accurate protocols for the reliable verification of the causative species and its relationship with potential damage claims. One of such conflicts is that occurring between apiarists and bee-eaters. In this work, we aim to assess the utility of passive acoustic monitoring (PAM) as an efficient methodology to measure European bee-eater (Merops apiaster) predation pressure at beehives and its impact on honeybees foraging activity. Using Autonomous Recording Units (ARUs) in apiaries, coupled to automated recognition methods for bee-eater calls identification, we found a positive relationship between Vocal Activity Rate (VAR) index and number of bee-eaters hunting attempts on honeybees. We also found that VAR varied over time, showing a lower predation pressure during midday hours and higher during the post-breeding migratory period. Honeybees flying activity was negatively associated with VAR and this relationship was conditioned by the hour of the day. Our study offers a new application of PAM and acoustic derived indices for the evaluation of potential damages caused by wildlife. We focused on the interaction between honeybees and the European bee-eater, but we expect PAM might be useful also to remotely monitor impacts to human activities produced by other vocally active species.European bee-eater monitoring was funded by the Department of Territory and Sustainability of the Generalitat de Catalunya. ARUs conception and design were partially supported by Programa de Investigación y Conservación del Zoo de Barcelona within the project ‘Nuevas tecnologías para viejos trabajos. Uso de grabadores automáticos para la detección y censo de especies raras y amenazadas. El caso de la alondra ricotí en Lleida y otras poblaciones pequeñas’. CPG acknowledges the support from Ministerio de Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo – Convocatoria 2020)

Low-cost open-source recorders and ready-to-use machine learning approaches provide effective monitoring of threatened species

Passive acoustic monitoring is a powerful tool for monitoring vocally active taxa. Automated signal recognition software reduces the expert time needed for recording analyses and allows researchers and managers to manage large acoustic datasets. The application of state-of-the-art techniques for automated identification, such as Convolutional Neural Networks, may be challenging for ecologists and managers without informatics or engineering expertise. Here, we evaluated the use of AudioMoth — a low-cost and open-source sound recorder — to monitor a threatened and patchily distributed species, the Eurasian bittern (Botaurus stellaris). Passive acoustic monitoring was carried out across 17 potential wetlands in north Spain. We also assessed the performance of BirdNET — an automated and freely available classifier able to identify over 3000 bird species — and Kaleidoscope Pro — a user-friendly recognition software — to detect the vocalizations and the presence of the target species. The percentage of presences and vocalizations of the Eurasian bittern automatically detected by BirdNET and Kaleidoscope software was compared to manual annotations of 205 recordings. The species was effectively recorded up to distances of 801–900 m, with at least 50% of the vocalizations uttered within that distance being manually detected; this distance was reduced to 601–700 m when considering the analyses carried out using Kaleidoscope. BirdNET detected the species in 59 of the 63 (93.7%) recordings with known presence of the species, while Kaleidoscope detected the bittern in 62 recordings (98.4%). At the vocalization level, BirdNet and Kaleidoscope were able to detect between 76 and 78%, respectively, of the vocalizations detected by a human observer. Our study highlights the ability of AudioMoth for detecting the bittern at large distances, which increases the potential of that technique for monitoring the species at large spatial scales. According to our results, a single AudioMoth could be useful for monitoring the species' presence in wetlands of up to 150 ha. Our study proves the utility of passive acoustic monitoring, coupled with BirdNet or Kaleidoscope Pro, as an accurate, repeatable, and cost-efficient method for monitoring the Eurasian bittern at large spatial and temporal scales. Nonetheless, further research should evaluate the performance of BirdNET on a larger number of species, and under different recording conditions (e.g., more closed habitats), to improve our knowledge about BirdNET's ability to perform bird monitoring. Future studies should also aim to develop an adequate protocol to perform effective passive acoustic monitoring of the Eurasian bittern.CPG acknowledges the support from the Ministerio de Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo – Convocatoria 2020)