Barotrauma is a significant cause of bat fatalities at wind turbines

SummaryBird fatalities at some wind energy facilities around the world have been documented for decades, but the issue of bat fatalities at such facilities — primarily involving migratory species during autumn migration — has been raised relatively recently [1,2]. Given that echolocating bats detect moving objects better than stationary ones [3], their relatively high fatality rate is perplexing, and numerous explanations have been proposed [1]. The decompression hypothesis proposes that bats are killed by barotrauma caused by rapid air-pressure reduction near moving turbine blades [1,4,5]. Barotrauma involves tissue damage to air-containing structures caused by rapid or excessive pressure change; pulmonary barotrauma is lung damage due to expansion of air in the lungs that is not accommodated by exhalation. We report here the first evidence that barotrauma is the cause of death in a high proportion of bats found at wind energy facilities. We found that 90% of bat fatalities involved internal haemorrhaging consistent with barotrauma, and that direct contact with turbine blades only accounted for about half of the fatalities. Air pressure change at turbine blades is an undetectable hazard and helps explain high bat fatality rates. We suggest that one reason why there are fewer bird than bat fatalities is that the unique respiratory anatomy of birds is less susceptible to barotrauma than that of mammals

Patient and provider experiences with virtual care during the COVID-19 pandemic: A mixed methods study

The COVID-19 pandemic prompted the rapid uptake of Virtual Care (VC). Positive patient outcomes with VC are previously reported but little is known about the experiences of patients and providers using VC during the pandemic. We aimed to describe patient and primary care provider experiences, satisfaction, perceptions, and attitudes to VC during the COVID-19 pandemic that might explain adoption of VC across the continuum of care and inform sustained uptake. We conducted a sequential explanatory mixed methods study using online surveys and virtual interviews with a convenience sample of primary care providers and patients in a Canadian province (July – December 2020). Eligible participants included patients and primary care providers using VC during the COVID-19 pandemic. Survey responses and interviews were analyzed using descriptive statistics and thematic analysis, respectively. Overall satisfaction was compared using the Mann-Whitney U test. Eighty-five patients and 94 primary care providers responded to the surveys. Patients reported higher overall satisfaction with VC than primary care providers (median [interquartile range]: 4.4 [4.0-4.7] and 3.7 [3.4-3.9] p \u3c 0.001). Ten patients and 11 primary care providers were interviewed. Both groups strongly appreciated VC’s increased access and convenience, identified the lack of compensation as a pre-pandemic barrier to providing VC, and reported willingness to continue VC post-COVID-19 pandemic. The COVID-19 pandemic provided an opportunity for patients and primary care providers to rapidly adopt VC with high satisfaction. Patients and primary care providers viewed VC positively due to its convenience and accessibility; both intend to continue using VC post-pandemic. Experience Framework This article is associated with the Staff & Provider Engagement lens of The Beryl Institute Experience Framework (https://www.theberylinstitute.org/ExperienceFramework). Access other PXJ articles related to this lens. Access other resources related to this lens

Movement Ecology and Conservation of the Migratory Bats Lasiurus cinereus and Lasionycteris noctivagans

Little is known about bat migration, but recently, fatalities of migratory bats at wind energy facilities across North America have offered the opportunity to gain insight into migratory-bat behaviour. Using a combination of stable-isotope and genetic analyses, I studied patterns of movement and relatedness of two species of migratory tree-roosting bats frequently killed by wind turbines: hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans). Using stable isotopes of nitrogen (δ15N), carbon (δ13C), and hydrogen (δ2H) of the fur of bat carcasses collected at a wind energy facility in south-western Alberta, I determined that the bats killed were migratory and originated from latitudes 100s-1000’s of kilometers to the north, with silver-haired bat originating from further north than hoary bats. The relationships between stable isotopes and arrival date suggests that the timing of migration may be governed by local habitat cues rather than latitudinal cues. I used a highly polymorphic portion (HVII) of the mitochondrial DNA control region and developed multilocus microsatellite markers to investigate the population genetics of hoary bats and silver-haired bats recovered at wind energy facilities in three Canadian provinces. Pairwise Fst values suggest subtle population-genetic structure among sites in both species, but greater structure in silver-haired bats. Two different Bayesian clustering analyses, STRUCTURE and TESS, suggested that there are at least two genetic clusters of hoary bats and six genetic clusters of silver-haired bats across the three sites. Lastly, I used microsatellite markers to examine whether bats learn migratory routes and behaviours from other closely related individuals. I tested whether the time between when individual bats were killed at a wind energy facility was influenced by their degree of relatedness and found that bats do not appear to be learning migratory routes or behaviours from closely related individuals. This suggests that bats may rely on endogenous genetic programs for migration and that migration may be a heritable trait

Variation in the activity and fatality of migratory bats at Wind Energy facilities in southern Alberta: causes and consequences

Bibliography: p.89-103some pages are in colou

genotypes of 132 hoary bats and 87 silver-haired bats from Alberta, Canada

Excel file containing genotypes of 132 hoary bats (Lasiurus cinereus) and 87 silver-haired bats (Lasionycteris noctivagans) collected at a wind energy facility in south-western Alberta, Canada in 2006 and 2007. Hoary bats were genotyped at 19 loci and silver-haired bats at 18 loci. This data was used to determine relatedness of individuals, so includes the year the individual was killed and their age/sex

Data from: Are migratory behaviours of bats socially transmitted?

To migrate, animals rely on endogenous, genetically inherited programmes, or socially transmitted information about routes and behaviours, or a combination of the two. In long-lived animals with extended parental care, as in bats, migration tends to be socially transmitted rather than endogenous. For a young bat to learn migration via social transmission, they would need to follow an experienced individual, most likely one roosting nearby. Therefore, we predicted that bats travelling together originate from the same place. It is also likely that young bats would follow their mothers or other kin, so we predicted that bats travelling together are more closely related to each other than bats not travelling together. To test our predictions, we used microsatellite genotypes and stable isotope values of δ13C, δ15N and δ2H to analyse the relatedness and geographical origins of migrating hoary bats (Lasiurus cinereus/Aeorestes cinereus (Baird et al. 2015 J. Mammal. 96, 1255–1274 (doi:10.1093/jmammal/gyv135)); n = 133) and silver-haired bats (Lasionycteris noctivagans; n = 87) killed at wind turbines over two consecutive autumn migrations. Contrary to our predictions, there was no evidence that related dyads of hoary bats or silver-haired bats were killed on the same night more frequently than expected by chance, or that the number of days between the fatalities of dyad members was influenced by relatedness or latitude of origin. Our data suggest that these bats do not socially transmit migration routes and behaviours among close kin

Impacts of wind energy development on bats : A global perspective

Wind energy continues to be one of the fastest growing renewable energy sources under development, and while representing a clean energy source, it is not environmentally neutral. Large numbers of bats are being killed at utility-scale wind energy facilities worldwide, raising concern about cumulative impacts of wind energy development on bat populations. We discuss our current state of knowledge on patterns of bat fatalities at wind facilities, estimates of fatalities, mitigation efforts, and policy and conservation implications. Given the magnitude and extent of fatalities of bats worldwide, the conservation implications of understanding and mitigating bat fatalities at wind energy facilities are critically important and should be proactive and based on science rather than being reactive and arbitrary

Evidence of late-summer mating readiness and early sexual maturation in migratory tree-roosting bats found dead at wind turbines

Understanding animal mating systems is an important component of their conservation, yet the precise mating times for many species of bats are unknown. The aim of this study was to better understand the details and timing of reproductive events in species of bats that die most frequently at wind turbines in North America, because such information can help inform conservation strategies. We examined the reproductive anatomy of hoary bats (Lasiurus cinereus), eastern red bats (L. borealis), and silver-haired bats (Lasionycteris noctivagans) found dead beneath industrial-scale wind turbines to learn more about when they mate. We evaluated 103 L. cinereus, 18 L. borealis, and 47 Ln. noctivagans from wind energy facilities in the United States and Canada. Histological analysis revealed that most male L. cinereus and L. borealis, as well as over half the Ln. noctivagans examined had sperm in the caudae epididymides by late August, indicating readiness to mate. Testes regression in male hoary bats coincided with enlargement of seminal vesicles and apparent growth of keratinized spines on the glans penis. Seasonality of these processes also suggests that mating could occur during August in L. cinereus. Spermatozoa were found in the uterus of an adult female hoary bat collected in September, but not in any other females. Ovaries of all females sampled had growing secondary or tertiary follicles, indicating sexual maturity even in first-year females. Lasiurus cinereus, L. borealis, and Ln. noctivagans are the only North American temperate bats in which most first-year young of both sexes are known to sexually mature in their first autumn. Our findings provide the first detailed information published on the seasonal timing of mating readiness in these species most affected by wind turbines

Total number of keratinized spines on the glans penises of (A) hoary bats (<i>Lasiurus cinereus</i>) and (B) eastern red bats (<i>L. borealis</i>) found dead beneath wind turbines, as a function of Julian day of year (from June 29 [Julian day 180] to October 27 [day 300]).

<p>Total number of keratinized spines on the glans penises of (A) hoary bats (<i>Lasiurus cinereus</i>) and (B) eastern red bats (<i>L. borealis</i>) found dead beneath wind turbines, as a function of Julian day of year (from June 29 [Julian day 180] to October 27 [day 300]).</p