Sex-Specific Habitat Preferences of Foraging and Commuting Lesser Horseshoe Bats<i>Rhinolophus hipposideros</i>(Borkhausen, 1797) in Lowland England

Stone

et al. 2018

Global Change Biology

The rapid global spread of artificial light at night is causing unprecedented disruption to ecosystems. In otherwise dark environments, street lights restrict the use of major flight routes by some bats, including the threatened lesser horseshoe bat Rhinolophus hipposideros, and may disrupt foraging. Using radio tracking, we examined the response of individual female R. hipposideros to experimental street lights placed on hedgerows used as major flight routes. Hedgerows were illuminated on one side over four nights using lights with different emission spectra, while the opposite side of the hedge was not illuminated. Automated bat detectors were used to examine changes in overall bat activity by R. hipposideros and other bat species present. R. hipposideros activity reduced significantly under all light types, including red light, challenging a previously held assumption that red light is safe for bats. Despite this, R. hipposideros rapidly adapted to the presence of lights by switching their flight paths to the dark side of the hedgerow, enabling them to reach foraging sites without restriction. Red light had no effect on the activity of the other species present. Slow‐flying Myotis spp. avoided orange, white and green light, while more agile Pipistrellus spp. were significantly more active at these light types compared to dark controls, most probably in response to accumulations of insect prey. No effect of any light type was found for Nyctalus or Eptesicus spp. Our findings demonstrate that caution must be used when promoting forms of lighting that are thought to be safe for wildlife before they are tested more widely. We argue that it is essential to preserve dark corridors to mitigate the impacts of artificial light at night on bat activity and movements.

Section: Discussionsupporting

confidence: 91%

Experimentally manipulating light spectra reveals the importance of dark corridors for commuting bats

Stone

et al. 2018

Global Change Biology

“…), and selection of roosting and foraging areas (Downs et al . , Istvanko et al . ) have been reported for numerous species of mostly temperate bats.…”

mentioning

confidence: 99%

“…Sexual dimorphism is rare among bats, the second most diverse mammalian order (Altringham 2011). However, genderspecific differences in attributes such as aggressiveness toward conspecifics (Ancillotto & Russo 2014), prey composition (Mata et al 2016), and selection of roosting and foraging areas (Downs et al 2016, Istvanko et al 2016 have been reported for numerous species of mostly temperate bats. Yet, notwithstanding some notable exceptions (e.g., Evelyn & Stiles 2003, Henry & Kalko 2007, Frank et al 2016, Orr et al 2016, differences between sexes in their tropical counterparts remain largely unexplored.…”

mentioning

confidence: 99%

Does sex matter? Gender‐specific responses to forest fragmentation in Neotropical bats

et al. 2017

Understanding the consequences of habitat modification on wildlife communities is central to the development of conservation strategies. However, albeit male and female individuals of numerous species are known to exhibit differences in habitat use, sex‐specific responses to habitat modification remain little explored. Here, we used a landscape‐scale fragmentation experiment to assess, separately for males and females, the effects of fragmentation on the abundance of Carollia perspicillata and Rhinophylla pumilio, two widespread Neotropical frugivorous bats. We predicted that sex‐specific responses would arise from higher energetic requirements from pregnancy and lactation in females. Analyses were conducted independently for each season, and we further investigated the joint responses to local and landscape‐scale metrics of habitat quality, composition, and configuration. Although males and females responded similarly to a fragmentation gradient composed by continuous forest, fragment interiors, edges, and matrix habitats, we found marked differences between sexes in habitat use for at least one of the seasons. Whereas the sex ratio varied little in continuous forest and fragment interiors, females were found to be more abundant than males in edge and matrix habitats. This difference was more prominent in the dry season, the reproductive season of both species. For both species, abundance responses to local‐ and landscape‐scale predictors differed between sexes and again, differences were more pronounced in the dry season. The results suggest considerable sex‐mediated responses to forest disruption and degradation in tropical bats and complement our understanding of the impacts of fragmentation on tropical forest vertebrate communities.

“…This ever larger number of people requires more and more food ( Daily et al 1998 ), which entails expanding the area of farmed land or intensifying crop cultivation. This, in turn, leads to changes in the farmland landscape structure ( Tilman et al 2011 ; Su et al 2014 ), depriving it of microhabitats and key elements of the landscape that are indispensable for many species ( McLaughlin and Mineau 1995 ; Aschwanden et al 2005 ; Downs et al 2016 ; Yahya et al 2016 ; Simons et al 2017 ). The use of artificial fertilizers and pesticides not only impoverishes the living conditions of plants consumed by or functioning as hosts for a whole range of herbivores ( Tang et al 2014 ; Broyer et al 2017 ); these substances also poison animals directly, an effect that is potentiated at every successive trophic level ( Mineau et al 1999 ; Gervais et al 2000 ).…”

mentioning

confidence: 99%

Noise shapes the distribution pattern of an acoustic predator

Fröhlich

Ciach

2017

Current Zoology

Noise, an obvious effect of urbanization, has a negative impact on animal vocalizations and the hunting efficiency of acoustic predators. However, the influence of noise pollution on the spatial distribution of populations remains understudied. The aim was to assess the factors shaping the distribution pattern of an acoustic predator (long-eared owl Asio otus) in an urban–farmland matrix. We hypothesized that the probability of an acoustic predator occurring decreases with growing nocturnal noise emission. This owl survey was conducted in Kraków (S Poland) on 79 randomly selected sample plots (1 km × 1 km). Six habitat variables (area of parks, woodlands, grassland, arable land, habitat diversity index, and noise pollution) were identified and correlated with the probability of the species’ occurrence. Proximity to pedestrian routes and roads, habitat fragmentation, and noise intensity was also defined at nest sites and random sites. Long-eared owls occurred on 37% of the sample plots. Occupied plots had a greater area of grassland and arable land as well as a lower level of noise pollution than the unoccupied ones. A multivariate model revealed that area of grassland and nocturnal noise emission was significantly correlated with the probability of long-eared owls occurring and that the high probability of occurrence recorded on plots with large areas of grassland was reduced by noise pollution. The noise intensity recorded at nest sites was also significantly lower than at random sites. This study suggests that apart from habitat factors, the distribution of acoustic predators in an urban matrix is driven by noise pollution. This highlights the importance of proper landscape management, that is, maintaining large grassland areas and preventing noise from increasing within them.