Managing hedgerows for nocturnal wildlife:Do bats and their insect prey benefit from targeted agri-environment schemes?

1. Mitigating the detrimental impacts of intensive farming on biodiversity requires the implementation of cost-effective conservation actions. Targeted agri-environment-schemes (AESs) to enhance populations of threatened species inhabiting farmland have been proposed for this purpose, yet their effectiveness for nocturnal wildlife remains unknown. 2. We assessed whether hedgerow management prescribed by targeted AESs to improve habitat conditions for the greater horseshoe bat (Rhinolophus ferrumequinum) in England may positively influence the species, the entire bat assemblage and the insect prey of bats. We specifically investigated the responses of bats (occurrence, activity, and species richness) and insects (biomass, abundance, and diversity) to time since last trimming (from 1 up to 10 years). We explored the mechanisms underlying the effects of AES via changes in trimming regime on bats. Moreover, we investigated the effects of landscape context on bats as we expected that highly mobile species would benefit further from landscape-scale management. 3. Bat species richness significantly increased with time since last trimming. Three bat taxa of major conservation concern in Western Europe substantially benefited from the targeted prescription, namely R. ferrumequinum, R. hipposideros and Plecotus spp. Insect-family richness and dipteran abundance were also significantly greater at hedgerows that were untrimmed for at least three years. The activity of more common bat species (i.e. pipistrelle bats) was not influenced by time since last trimming. 4. Changes in trimming regime strongly affected hedgerow height which directly and indirectly (by increasing prey abundance) influenced bat occurrence, activity and species richness along hedgerows. 5. The activity of highly mobile bat species was mainly associated with a range of landscape attributes. The amount of semi-natural grassland within 0.5 km of the sampling sites positively influenced R. ferrumequinum while the presence of urban areas negatively affected light-sensitive bat species. 6. Synthesis and applications. The implementation of targeted agri-environment-schemes can include effective measures to enhance bats and their insect prey in farmland. Although we highlight the success of current prescriptions on hedgerow management, we suggest that their effectiveness can easily be optimized by encouraging farmers to keep hedgerows untrimmed for longer periods (>3 up to 10 years). We also highlight that a multi-scale management approach is required to successfully promote bats in farmland

An Incremental Shuttle Walk Test to Estimate Maximal Aerobic Functional Capacity

Background: The goal of the present study was to compare the maximum walking speed and peak oxygen consumption (VO2 peak) obtained during the 6-min walk test (6 MWT) and an incremental shuttle walking test (ISWT) in a trained older population. Methods: A total of 22 older adults (16 female and 6 male) with a group mean age of 70&#177;5.8 yr (range 58 to 79) completed the 6 MWT and ISWT within a 2 wk period. Heart rate (HR) and VO2 peak were measured during each test with a portable metabolic cart (Cosmed, K4B2). The VO2 peak, the maximum walking speed and the total distance walked measured during both tests (6 MWT and ISWT) were compared. Results: A total of 110 recordings for the VO2 peak were obtained and analyzed. Strong correlations were found for the VO2 peak and the walking speed (r=0.91 and r=0.89, respectively, for 6 MWT and ISWT). VO2 peak values obtained with the ISWT were significantly greater (P < 0.05) than with the 6 MWT (21.6 &#177; 5.3 vs 18.9 ml/kgmin &#177; 4.5, respectively). There was no difference between sexes. In addition, the maximum heart rate as predicted from age during the ISWT was reached by all participants while it was not during the 6 MWT. Conclusion: Thus, the ISWT appears to a better tool to assess the maximal aerobic functional capacity in older healthy adults based on the higher VO2 peak values obtained in comparison to the 6 MWT

Santé et arrêt de tranche en centrale nucléaire : une étude épidémiologique

Une enquête épidémiologique, initiée en 1989, a été réalisée dans les centrales nucléaires de la vallée de la Loire et du Blayais. Elle porte sur les conditions de travail, l'organisation du travail et leurs liens avec la santé lors des arrêts de maintenance annuels dits arrêts de tranche programmés (ATP). Dans cette étude, transversale, la santé a été essentiellement examinée sous ses aspects psychologiques : anxiété et symptômes dépressifs (échelles de Spielberger et CES-D). Des comparaisons ont été effectuées en et hors arrêt, sur quatre groupes professionnels différemment sollicités, chaque sujet étant pris pour son propre témoin. Le test du khi-deux a été utilisé pour les variables qualitatives et le test sur la différence pour les variables quantitatives. On observe en ATP des heures supplémentaires et des horaires atypiques déclarés plus fréquents (p < 0,01), un rythme de travail et des règles de sécurité jugés plus contraignants, une exposition à l'irradiation jugée plus importante (p < 0,01). Des modifications de l'état psychologique en ATP ont été objectivées pour les agents de conduite alors qu'elles étaient attendues pour les agents de maintenance. Des résultats analogues ont été obtenus en tenant compte de la fréquence des arrêts. Des interprétations sont données en faisant référence à des études qualitatives sur le sujet. Ceci invite à prolonger la réflexion selon les deux axes d'approches, quantitatif et qualitatif

Timing of the evening emergence from day roosts of the grey-headed flying fox, Pteropus poliocephalus: the effects of predation risk, foraging needs, and social context

This study addresses the functional question of how variation in foraging strategy, predation risk, and social context influence the timing of the evening emergence from day roosts of the grey-headed flying fox, Pteropus poliocephalus. The onset of evening emergence was expected to vary according to the relative costs and benefits of emerging early and should, therefore, reflect an optimal trade-off between predation risks and foraging needs. The onset of the colony-wide emergence was closely correlated with the time of sunset and cloud cover. However, as expected, the onset of the colony-wide emergence was delayed when a diurnal avian predator was present, whereas the onset was advanced during lactation when presumably energetic demands are higher. The trade-off between predation risks and foraging needs was further reflected in the emergence times of individual bats: adult females emerged earlier when they had higher foraging needs as indicated by their body condition; young emerged later when they were smaller and likely to be more at risk from predation due to their less developed flying skills. However, the emergence time of adult males depended on their social status: smaller bachelor males emerged from the colony earlier than larger harem-holding males who guard their harems until the last female had left. Thus, whereas the colony-wide emergence time reflected the outcome of a trade-off between predation risks and general foraging needs, on an individual level, the outcome of this trade-off depended on sex, age, body condition, and structural size and was modified by social context