Wind farm facilities in Germany kill noctule bats from near and far

Over recent years, it became widely accepted that alternative, renewable energy may come at some risk for wildlife, for example, when wind turbines cause large numbers of bat fatalities. To better assess likely populations effects of wind turbine related wildlife fatalities, we studied the geographical origin of the most common bat species found dead below German wind turbines, the noctule bat (Nyctalus noctula). We measured stable isotope ratios of non-exchangeable hydrogen in fur keratin to separate migrants from local individuals, used a linear mixed-effects model to identify temporal, spatial and biological factors explaining the variance in measured stable isotope ratios and determined the geographical breeding provenance of killed migrants using isoscape origin models. We found that 72% of noctule bat casualties (n = 136) were of local origin, while 28% were long-distance migrants. These findings highlight that bat fatalities at German wind turbines may affect both local and distant populations. Our results indicated a sex and age-specific vulnerability of bats towards lethal accidents at turbines, i.e. a relatively high proportion of killed females were recorded among migratory individuals, whereas more juveniles than adults were recorded among killed bats of local origin. Migratory noctule bats were found to originate from distant populations in the Northeastern parts of Europe. The large catchment areas of German wind turbines and high vulnerability of female and juvenile noctule bats call for immediate action to reduce the negative cross-boundary effects of bat fatalities at wind turbines on local and distant populations. Further, our study highlights the importance of implementing effective mitigation measures and developing species and scale-specific conservation approaches on both national and international levels to protect source populations of bats. The efficacy of local compensatory measures appears doubtful, at least for migrant noctule bats, considering the large geographical catchment areas of German wind turbines for this species

Ship based cetacean survey Southern Ocean 2011/2012

Distance sampling survey for cetaceans in the Southern Ocean conducted on board of Polarstern during the austral summer 2011/2012. Effort related sighting data were collected en-route during a dedicated survey

Ship based cetacean survey Southern Ocean 2010/2011

Distance sampling survey for cetaceans in the Southern Ocean conducted on board of Polarstern during the austral summer 2010/2011. Effort related sighting data were collected en-route during a dedicated survey

Ship based cetacean survey Southern Ocean 2010/2011

Distance sampling survey for cetaceans in the Southern Ocean conducted on board of Polarstern during the austral summer 2010/2011. Effort related sighting data were collected en-route during a dedicated survey

Aerial cetacean survey Southern Ocean 2010/2011

Aerial distance sampling survey for cetaceans in the Southern Ocean conducted on board Polarstern during the Antarctic Expedition PS77 (ANT-XXVII/2) during austral summer 2010/2011. Effort related sighting data were collected during a dedicated survey following an ad-hoc sampling design

Aerial cetacean survey Southern Ocean 2011/2012

Aerial distance sampling survey for cetaceans in the Southern Ocean conducted on board Polarstern during the Antarctic Expedition PS79 (ANT-XXVIII/2) during austral summer 2011/2012. Effort related sighting data were collected during a dedicated survey following an ad-hoc sampling design

Aerial surveys for Antarctic minke whales (Balaenoptera bonaerensis) reveal sea ice dependent distribution patterns

Abstract This study investigates the distribution of Antarctic minke whales (AMW) in relation to sea ice concentration and variations therein. Information on AMW densities in the sea ice‐covered parts of the Southern Ocean is required to contextualize abundance estimates obtained from circumpolar shipboard surveys in open waters, suggesting a 30% decline in AMW abundance. Conventional line‐transect shipboard surveys for density estimation are impossible in ice‐covered regions, therefore we used icebreaker‐supported helicopter surveys to obtain information on AMW densities along gradients of 0%–100% of ice concentration. We conducted five helicopter surveys in the Southern Ocean, between 2006 and 2013. Distance sampling data, satellite‐derived sea‐ice data, and bathymetric parameters were used in generalized additive models (GAMs) to produce predictions on how the density of AMWs varied over space and time, and with environmental covariates. Ice concentration, distance to the ice edge and distance from the shelf break were found to describe the distribution of AMWs. Highest densities were predicted at the ice edge and through to medium ice concentrations. Medium densities were found up to 500 km into the ice edge in all concentrations of ice. Very low numbers of AMWs were found in the ice‐free waters of the West Antarctic Peninsula (WAP). A consistent relationship between AMW distribution and sea ice concentration weakens the support for the hypothesis that varying numbers of AMWs in ice‐covered waters were responsible for observed changes in estimated abundance. The potential decline in AMW abundance stresses the need for conservation measures and further studies into the AMW population status. Very low numbers of AMWs recorded in the ice‐free waters along the WAP support the hypothesis that this species is strongly dependent on sea ice and that forecasted sea ice changes have the potential of heavily impacting AMWs

Sampling locations of <i>Nyctalus noctula</i> carcasses (open circles) at wind turbines in the Eastern part of Germany.

<p>The seven major terrestrial natural regions in Germany <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103106#pone.0103106-BfN1" target="_blank">[26]</a> are shown in different shades of grey. Macrochores <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103106#pone.0103106-BfN1" target="_blank">[26]</a> within the major natural regions are indicated by solid lines.</p

Predicted geographical provenance of the 28% of migratory <i>Nyctalus noctula (n = 37)</i>, separated by females (A,B) and males (C,D) found dead below wind turbines in Eastern Germany.

<p>Geographical areas marked red are areas of likely breeding origin and those marked blue areas of unlikely breeding origin. Predictions shown in map A and C are based on δ²H_f. Predictions shown in map B and D incorporate additional information on the preferred cardinal heading of <i>N. noctula</i> during spring migration. Areas falling outside the distribution range of <i>N. noctula</i> according to the IUCN are overlaid with a semi-transparent layer.</p

Results of the linear mixed-effects model fit by REML for predicting δ²H_f from ‘season’, ‘sex’ and ‘migratory behaviour’ with ‘sampling location’ as random effect.

<p>Degrees of freedom: 88; number of observations: 136; number of groups (random effect ‘sampling location’): 45. AIC = 947.5, BIC = 964.8, logLik <b>−</b>467.8; random intercept (mean 0, SD 6.36), and residual term (mean 0, SD 6.31) were normally distributed.</p