Pronounced genetic structure and low genetic diversity in European red-billed chough (Pyrrhocorax pyrrhocorax) populations

Conservation Genetics August 2015, Volume 16, Issue 4, pp 1011–1012 Erratum to: Pronounced genetic structure and low genetic diversity in European red-billed chough (Pyrrhocorax pyrrhocorax) populations Erratum to: Conserv Genet (2012) 13:1213–1230 DOI 10.1007/s10592-012-0366-6 In the original publication, Tables 3 and 6 were published with incorrect estimates of population heterozygosities. All other diversity statistics were correct as originally presented. Updated versions of Tables 3 and 6 with corrected heterozygosity estimates confirmed using Arlequin 3.5 (Excoffier and Lischer 2010) as in Dávila et al. (2014) are provided in this erratum. Discrepancies were minor for populations on the British Isles. The correct estimates for Spain are slightly larger than those reported for La Palma by Dávila et al. (2014), but this does not necessarily affect their interpretation that choughs on La Palma may have originated from multiple migration events. The original conclusion that chough populations on the British Isles have low genetic diversity compared to continental European populations remains and is now, in fact, strengthened.Peer reviewedPostprin

Tourism in protected areas can threaten wild populations: from individual response to population viability of the chough Pyrrhocorax pyrrhocorax

International audienceMany protected areas are now faced with increasing pressure from visitors and tourism development. There is thus an urgent need for conservation biologists to evaluate the full impact of human disturbance not only on individual responses but also on the viability of protected populations so that relevant management measures can be proposed. We studied the impact of tourism on the rare and endangered chough Pyrrhocorax pyrrhocorax on a protected french island to assess the relationship between visitor pressure, bird individual behavior and fitness, and population viability. During 8 years, we monitored foraging behavior and estimated monthly juvenile survival using mark-recapture data. Population viability was examined under different tourism scenarios, using a stochastic individual-based model that incorporated the impact of visitor numbers on juvenile survival. In summer, the foraging probability of choughs was negatively correlated with the number of visitors. As a result, the time allocated to foraging during peak tourist season, adjusted to day length and prey availability, was 50% lower than expected. Juvenile survival rates were lowest in August, the peak tourist season, and varied significantly across years. August survival rate and therefore annual survival were negatively correlated with the number of visitors on the island in August and, except for a minor negative effect of rainfall, were not influenced by other environmental variables. Sthochastic simulations predicted a low probability of extinction of the protected population if the number of visitors remains constant in the future. However, short-term viability would be dramatically reduced if the current rate of increase in visitor numbers is maintained. We show that a relatively minor human-induced disturbance (e.g. scaring individuals away) has dramatic effects on population viability in a protected area, even when breeding individuals are not directly affected. This suggests that the full impact of tourism in protected areas may be overlooked, and has direct consequences for the assessment of sustainable levels of human distrurbance and the design of quantitative management options compatible with tourist activities in protected areas. We specifically emphasize the need for more integrative approaches combining research at individual and population levels

Plant and spider communities benefit differently from the presence of planted hedgerows in highway verges

International audienceRoad verges should play a crucial role as a refuge for native flora and fauna in human dominated landscapes. However, the influence of construction choices, such as plantation of woody species, on the biodiversity supported by roadsides has received little attention, although the presence of hedgerows in roadsides is likely to enhance their role as a refuge, notably for woodland species. Using standardised methods, we assessed the impact of planted hedgerows on two taxonomic groups (plants and spiders) inhabiting highway verges within an intensive agricultural landscape. We examined community richness, taxonomic and functional composition in sites with and without planted hedgerows. At the site level, the response of plant and spider communities to the presence of planted hedgerows differed markedly: hedgerows were associated with significantly higher plant richness (higher α-diversity), but similar spider richness. Plant communities in sites without hedgerows appeared as a subset of communities in sites with hedgerows, whereas spider communities in non-planted sites were complementary to that of planted sites (increased β-diversity). The presence of planted hedgerows was also associated with increased taxonomic and functional trait diversity at the landscape level (γ-diversity), through an increased β-diversity in both plants and spiders. Our results thus suggest that a mosaic of planted hedgerows and grassland habitats is crucial for the maintenance of biodiversity at a landscape scale. By providing information for road practitioners and policy makers regarding their potential impact on biodiversity, these results have important direct implications for the management of road networks

Conséquences sur l'avifaune terrestre de l'île de Trielen (réserve naturelle d'Iroise, Bretagne) de l'éradication du Rat surmulot (Rattus norvegicus)

The Norwegian Rat (Rattus norvegicus) invaded the Trielen Island (Iroise Natural Reserve, Brittany, France) during the beginning of the XXth century and was eradicated in 1996. Breeding pairs of all terrestrial bird species were censused annually, from 1996 before the eradication operation to 2001. None of the 7 occasional breeding species (two being a priori exposed to Norwegian Rat predation) established as a regular breeder after the eradication operation. On the other hand, numbers of breeding pairs increased by a factor of 1.7 to 2.0 for the Dunnock (Prunella modularis), 2.2 to 2.7 for the Wren (Troglodytes troglodytes), and 5.5 to 7.0 for the Rock Pipit (Anthus petrosus). Many biological facts converged to identify the rodent disappearance as the major driving factor of these increases. This Norwegian Rat eradication was particularly pertinent as a biological conservation operation, because of its positive effect on the local Rock Pipit (Anthus petrosus) population as the French coast hosts near 50 % of the subspecies petrosus world population. The 2001 Trielen Island abundance index (26 to 46 breeding pairs per coastal km) was among the highest known ones for that species. The large and quick increase following the disappearance of the Norwegian Rat showed the high sensibility of the Rock Pipit to mammalian predationL'inventaire du nombre de couples nicheurs du peuplement d'oiseaux terrestres de l'île de Trielen (Réserve Naturelle d'Iroise, Bretagne) a été réalisé annuellement entre 1996 et 2001, suite à l'éradication, en 1996, de la population du Rat surmulot (Rattus norvegicus) installée sur l'île depuis le début du XXe siècle. La disparition du rongeur ne s'est accompagnée, ni d'apparition où de disparition d'espèces, ni de la pérennisation de la reproduction de 7 espèces réputées nicher occasionnellement sur le site, deux d'entre elles étant a priori vulnérables au comportement de prédation exercé par le Surmulot. Les effectifs de couples nicheurs de l'Accenteur mouchet (Prunella modularis), du Troglodyte mignon (Troglodytes troglodytes), et du Pipit maritime (Anthus petrosus), espèces a priori toutes vulnérables au comportement de prédation du rongeur, ont été multipliés respectivement par un facteur de 1,7 à 2,0, de 2,2 à 2,7 et de 5,5 à 7,0. Les faits convergent pour désigner l'éradication du rongeur comme le facteur de causalité majeur de ces augmentations. Cette opération qui relève de la biologie de la conservation est particulièrement pertinente vis-à-vis du Pipit maritime dont le linéaire côtier français accueille près de 50 % de la population mondiale de la sous-espèce petrosus. L'indice d'abondance relevé en 2001 sur l'île de Trielen (26 à 46 couples nicheurs par km de linéaire côtier) compte parmi les plus élevés connus à ce jour pour l'espèce. Son fort accroissement, suite à la disparition du Surmulot, témoigne de la sensibilité de l'espèce à la prédation mammalienne

DIET AND FUELLING OF THE GLOBALLY THREATENED AQUATIC WARBLER ACROCEPHALUS 1 PALUDICOLA AT AUTUMN MIGRATION STOPOVER AS COMPARED WITH TWO CONGENERS

International audienceThe effective conservation of aquatic warbler (Acrocephalus paludicola), one of the most threatened western Palaearctic migratory passerines, requires good knowledge of its ecological needs at stopover sites. In particular, identifying its diet, which controls the accumulation of fat reserves during migration, facilitates the selection and management of adequately protected areas. Further key information includes the relationship between prey species abundance and habitats of aquatic warbler on stopover. We performed standardised mist-netting in the Audierne marshes (western France) during 12 years, which resulted in the capture of 1,200 aquatic warblers, and provided measurements for mass gain and the collection of faeces to infer the birds’ diet. Invertebrate sampling was carried out in the three main Audierne marshhabitats(reedbed, fen mire and meadow). In order to go beyond prey digestibility bias,we also studied two closely related Acrocephalusspecies, present at migration stopover sites during the same period. We found that the diet composition of aquatic warbler observed at migration stopover sites is based on large-sizedprey (Odonata, Orthoptera, Lepidoptera).Likes edge warblers, aquatic warblers put on weight during migration stopovers (daily mass gain =0.38g). This increase in weight suggests that the aquatic warblers might have adopted a strategy for long-distance migration with few stopovers only. Due to great differences in diet, conservation management for the threatened aquatic warbler at stopover sites should not rely on existing knowledge abouts edge and reed warblers. Similarities in the diet of aquatic warbler between nesting areas and migration stopover areas and the relationship between habitat and prey abundance suggest that fen mires play an important role in the quality of the for aging habitat at stopover site

Acoustic activity of bats at power lines correlates with relative humidity: a potential role for corona discharges

With the ever-increasing dependency on electric power, electrical grid networks are expanding worldwide. Bats exhibit a wide diversity of foraging and flight behaviours, and their sensitivity to anthropogenic stressors suggests this group is very likely to be affected by power lines in a myriad of ways. Yet the effects of power lines on bats remains unknown. Here we assessed the responses of insectivorous bats to very high voltage power lines (VHVPL; greater than 220 kV). We implemented a paired sampling design and monitored bats acoustically at 25 pairs, one pair consisting of one forest edge near to VHVPL matched with one control forest edge. Relative humidity mediates the effects of power lines on bats: we detected bat attraction to VHVPL at high relative humidity levels and avoidance of VHVPL by bats at low relative humidity levels. We argue that the former could be explained by insect attraction to the light emitted by VHVPL owing to corona discharges while the latter may be owing to the physical presence of pylons/cables at foraging height and/or because of electromagnetic fields. Our work highlights the response of bats to power lines at foraging habitats, providing new insight into the interactions between power lines and biodiversity

Acoustic activity of bats at power lines correlates with relative humidity: a potential role for corona discharges

With the ever-increasing dependency on electric power, electrical grid networks are expanding worldwide. Bats exhibit a wide diversity of foraging and flight behaviours, and their sensitivity to anthropogenic stressors suggests this group is very likely to be affected by power lines in a myriad of ways. Yet the effects of power lines on bats remains unknown. Here we assessed the responses of insectivorous bats to very high voltage power lines (VHVPL; greater than 220 kV). We implemented a paired sampling design and monitored bats acoustically at 25 pairs, one pair consisting of one forest edge near to VHVPL matched with one control forest edge. Relative humidity mediates the effects of power lines on bats: we detected bat attraction to VHVPL at high relative humidity levels and avoidance of VHVPL by bats at low relative humidity levels. We argue that the former could be explained by insect attraction to the light emitted by VHVPL owing to corona discharges while the latter may be owing to the physical presence of pylons/cables at foraging height and/or because of electromagnetic fields. Our work highlights the response of bats to power lines at foraging habitats, providing new insight into the interactions between power lines and biodiversity

Toward solving the global green-green dilemma between wind energy production and bat conservation.

Wind energy production is growing rapidly worldwide in an effort to reduce greenhouse gas emissions. However, wind energy production is not environmentally neutral. Negative impacts on volant animals, such as bats, include fatalities at turbines and habitat loss due to land-use change and displacement. Siting turbines away from ecologically sensitive areas and implementing measures to reduce fatalities are critical to protecting bat populations. Restricting turbine operations during periods of high bat activity is the most effective form of mitigation currently available to reduce fatalities. Compensating for habitat loss and offsetting mortality are not often practiced, because meaningful offsets are lacking. Legal frameworks to prevent or mitigate the negative impacts of wind energy on bats are absent in most countries, especially in emerging markets. Therefore, governments and lending institutions are key in reconciling wind energy production with biodiversity goals by requiring sufficient environmental standards for wind energy projects

Articulating citizen science, semi-automatic identification and free web services for long-term acoustic monitoring: examples from France and UK

Monitoring biodiversity over large spatial and temporal scales is crucial for assessing the impact of global changes and environmental mitigation measures. Bats often have high conservation prioritisation owing to their trophic position, habitat associations and threat level, and many have dedicated management plans. However, poor knowledge of species' ecology, identification issues and surveying challenges mean that large-scale monitoring to produce required distribution and abundance information is less developed than for some other taxa. Exciting possibilities applicable to professional and citizen science are offered by new recording techniques and methods of semi-automated species recognition based on sound detection. Static detectors deployed to record bats throughout whole nights have been recommended for standardised acoustic monitoring but until recently cost and lack of software to support the analyses of such data has prohibited wide uptake. Such monitoring schemes have recently been deployed in both Britain and France allowing the fast and standardized collection of millions of bat records together with very interesting data on non-targeted taxa such as bush-crickets. Such data management led us to develop generic and open tools: (1) the Tadarida software toolbox providing a generic detection and classification of sound events, and (2) an open dedicated web portal (www.vigiechiro.herokuapp.com) to allow participants to manage and upload their data, then being processed trough Tadarida to get a quick feedback on the content of the data. We demonstrate how such data can accurately describe pronounced ecological patterns for numerous species at different scales: spatial variation in activity as a proxy for relative abundance, habitat selection and phenology of seasonal and nocturnal activity. If maintained in the long term, such schemes will also greatly improve estimates of species temporal trends and hence the assessment of conservation priorities. The feedback produced by these two monitoring schemes allows us the opportunity to provide recommendations for the sustainability of long-term acoustic monitoring of bats. These include a database that is adaptively managed to allow all raw data to be re-analysed every time automatic identification makes significant progress, while keeping the link with expert validation to ensure consistency in the semi-automated process. More importantly, there are real benefits of developing long-term acoustic monitoring within a collaborative framework. Specifically, (1) for collaboration among bat scientists for the collection of reference sound data, because diversity and quantity of the reference library remains a limiting factor for automatic identification, and (2) for work on bats to consider the wider acoustic monitoring of other species groups by working with other zoologists to share resources and costs