Habitat use by the eastern horseshoe bat, Rhinolophus megaphyllus, in a fragmented woodland mosaic

1998 ◽  
Vol 25 (5) ◽  
pp. 489 ◽  
Author(s):  
Chris R. Pavey

I examined habitat use by eastern horseshoe bats, Rhinolophus megaphyllus, in a fragmented woodland mosaic in south-east Queensland, Australia. I predicted that the species would forage within the remaining woodland remnants in the mosaic, because its flight pattern and auditory system are adapted for locating and capturing prey in cluttered habitat (i.e. close to and within vegetation). I studied habitat use by light-tagging and radio-tagging bats that roosted in a disused mine in a large woodland fragment. I observed bats within an area of 95 ha, which was composed of grassland (71% of area), woodland (14%), and edge habitat (boundary of woodland and grassland, and isolated trees in grassland – 15%). Bats foraged in woodland and edge habitat but not over grassland, and used woodland significantly more often than expected by its availability. Commuting bats left the woodland fragment in which the roost was located by one of two routes, both of which led into riparian woodland. One route was entirely within woodland, whereas the other route crossed 250 m of open ground. The study indicates that R. megaphyllus should respond negatively to the fragmentation of woodland and forest because this process will reduce the availability of its preferred foraging habitat.

2008 ◽  
Vol 99 (1) ◽  
pp. 284-296 ◽  
Author(s):  
Feng Luo ◽  
Walter Metzner ◽  
Feijian J. Wu ◽  
Shuyi Y. Zhang ◽  
Qicai C. Chen

The present study examines duration-sensitive neurons in the inferior colliculus (IC) of the least horseshoe bat, Rhinolophus pusillus, from China. In contrast to other bat species tested for duration selectivity so far, echolocation pulses emitted by horseshoe bats are generally longer and composed of a long constant-frequency (CF) component followed by a short downward frequency-modulated (FM) sweep (CF-FM pulse). We used combined CF-FM pulses to analyze the differential effects that these two pulse components had on the duration tuning in neurons of the horseshoe bat's IC. Consistent with results from other mammals, duration-sensitive neurons found in the least horseshoe bat fall into three main classes: short-pass, band-pass, and long-pass. Using a CF stimulus alone, 54% (51/95) of all IC neurons showed at least one form of duration selectivity at one or more stimulus intensities. In 65 of the 95 IC neurons tested with CF pulses, we were also able to test their duration selectivity for a combined CF-FM pulse, which increased the ratio of duration-sensitive neurons to 66% (43/65). Seven to 15 neurons that failed to show duration tuning for CF bursts became duration sensitive for CF-FM pulses, with most of them exhibiting short-pass (depending on stimulus intensity, between 4 and 8 neurons) or band-pass tuning (1–3 neurons). Increasing stimulus intensities did not affect the duration tuning in 53% (23/43) of duration-sensitive neurons for CF bursts and in about 26% (7/27) for CF-FM stimuli. In the remaining neurons, increasing sound levels generally reduced the ratio of duration-sensitive neurons to 33% for CF and 37% for CF-FM stimulation. In those that remained duration sensitive, louder CF bursts shortened best durations in band-pass neurons and cutoff durations in short- and long-pass neurons, whereas louder CF-FM stimuli reduced the cutoff durations only in short-pass neurons. Bandwidths of band-pass neurons were not significantly affected by any stimulus configuration, with only a slight trend for increasing bandwidths for louder CF bursts (but not CF-FM stimuli). Best durations and cutoff durations reached higher values than those in the other bat species examined so far and roughly match the longer durations of echolocation pulses emitted by horseshoe bats. Therefore presentation of a CF-FM stimulus improved the duration sensitivity in IC neurons by increasing the ratio of duration-tuned neurons and making them less susceptible to changes in signal intensity.


2021 ◽  
Author(s):  
Xiran Wang ◽  
Zhihua Ou ◽  
Peiwen Ding ◽  
Chengcheng Sun ◽  
Daxi Wang ◽  
...  

Horseshoe bats (Rhinolophus sinicus) might help maintain coronaviruses severely affecting human health, such as SARS-CoV and SARS-CoV-2. It has long been suggested that bats may be more tolerant of viral infection than other mammals due to their unique immune system, but the exact mechanism remains to be fully explored. During the COVID-19 pandemic, multiple animal species were diseased by SARS-CoV-2 infection, especially in the respiratory system. Herein, single-cell transcriptomic data of the lungs of a horseshoe bat, a cat, a tiger, and a pangolin were generated. The receptor distribution of twenty-eight respiratory viruses belonging to fourteen viral families were characterized for the four species. Comparison on the immune-related transcripts further revealed limited cytokine activations in bats, which might explain the reason why bats experienced only mild diseases or even no symptoms upon virus infection. Our findings might increase our understanding of the immune background of horseshoe bats and their insensitivity to virus infections.


Author(s):  
Huihui Mou ◽  
Brian D. Quinlan ◽  
Haiyong Peng ◽  
Yan Guo ◽  
Shoujiao Peng ◽  
...  

SUMMARYThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein mediates infection of cells expressing angiotensin-converting enzyme 2 (ACE2). ACE2 is also the viral receptor of SARS-CoV (SARS-CoV-1), a related coronavirus that emerged in 2002-2003. Horseshoe bats (genus Rhinolophus) are presumed to be the original reservoir of both viruses, and a SARS-like coronavirus, RaTG13, closely related SARS-CoV-2, has been isolated from one horseshoe-bat species. Here we characterize the ability of S-protein receptor-binding domains (RBDs) of SARS-CoV-1, SARS-CoV-2, and RaTG13 to bind a range of ACE2 orthologs. We observed that the SARS-CoV-2 RBD bound human, pangolin, and horseshoe bat (R. macrotis) ACE2 more efficiently than the SARS-CoV-1 or RaTG13 RBD. Only the RaTG13 RBD bound rodent ACE2 orthologs efficiently. Five mutations drawn from ACE2 orthologs of nine Rhinolophus species enhanced human ACE2 binding to the SARS-CoV-2 RBD and neutralization of SARS-CoV-2 by an immunoadhesin form of human ACE2 (ACE2-Fc). Two of these mutations impaired neutralization of SARS-CoV-1. An ACE2-Fc variant bearing all five mutations neutralized SARS-CoV-2 five-fold more efficiently than human ACE2-Fc. These data narrow the potential SARS-CoV-2 reservoir, suggest that SARS-CoV-1 and -2 originate from distinct bat species, and identify a more potently neutralizing form of ACE2-Fc.


2014 ◽  
Vol 7 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Carolyn A. Gaudet ◽  
Christopher M. Somers

Shoreline development and boating on lakes of the northern Great Plains of North America have increased due to recent economic prosperity. Few studies have examined the general characteristics of habitats used by foraging waterbirds and boats to determine levels of overlap. To address this issue, we conducted point count surveys of American White Pelicans (Pelecanus erythrorhynchos) and boats on two important recreational lakes in southern Saskatchewan, Canada. The majority of pelicans and boats detected used near-shore areas of the lakes, identifying the importance of shallow water habitats and providing evidence of significant overlap. The location of pelicans relative to the shore did not change in the presence of boats, and there was no significant relationship between boat numbers and pelican numbers. These analyses suggest that pelicans did not make major changes to their habitat use on the lakes as a result of boating activity. When pelicans and boats were present simultaneously at point count locations, pelicans appeared to avoid boats on one lake, but showed no detectable avoidance behavior on the other lake. The importance of interactions between recreational boating and foraging pelicans is currently unclear. Set-back distances to protect foraging pelicans from boating activity do not appear necessary based on our analyses.


2017 ◽  
Vol 131 (1) ◽  
pp. 37-45
Author(s):  
Graham P. Dixon-MacCallum ◽  
Katie A.H. Bell ◽  
Patrick T. Gregory

Understanding habitat requirements of species is fundamental for their conservation and urban parks can provide key habitat for species in otherwise disturbed settings. Northwestern Gartersnakes (Thamnophis ordinoides) are common in parks in Saanich, British Columbia, but their specific habitat requirements are poorly understood. Based on previous studies and thermoregulatory needs of snakes, we predicted that edges, particularly field margins, would be heavily used by active snakes. We therefore used surveys that focused on edges to find snakes and measured edge-habitat use by comparing habitat variables at locations where snakes were found to the same variables at nearby random locations. Habitat variables included composition and structure of vegetation, substrate temperature, aspect, and slope. Overall, litter depth, canopy cover, a lack of bare ground and woody vegetation were the most important habitat variables for determining where snakes were found. our results provide a preliminary assessment to improve our understanding of habitat use for this species. The abundance of snakes found while surveying edges supports our initial assumption that edges are important habitat features but more work is required using multiple survey methods to further test this hypothesis.


2020 ◽  
Vol 287 (1934) ◽  
pp. 20200875
Author(s):  
Haijian Sun ◽  
Wenli Chen ◽  
Jiaying Wang ◽  
Libiao Zhang ◽  
Stephen J. Rossiter ◽  
...  

Recently diverged taxa with contrasting phenotypes offer opportunities for unravelling the genetic basis of phenotypic variation in nature. Horseshoe bats are a speciose group that exhibit a derived form of high-duty cycle echolocation in which the inner ear is finely tuned to echoes of the narrowband call frequency. Here, by focusing on three recently diverged subspecies of the intermediate horseshoe bat ( Rhinolophus affinis ) that display divergent echolocation call frequencies, we aim to identify candidate loci putatively involved in hearing frequency variation. We used de novo transcriptome sequencing of two mainland taxa ( himalayanus and macrurus ) and one island taxon ( hainanus ) to compare expression profiles of thousands of genes. By comparing taxa with divergent call frequencies (around 15 kHz difference), we identified 252 differentially expressed genes, of which six have been shown to be involved in hearing or deafness in human/mouse. To obtain further validation of these results, we applied quantitative reverse transcription–PCR to the candidate gene FBXL15 and found a broad association between the level of expression and call frequency across taxa. The genes identified here represent strong candidate loci associated with hearing frequency variation in bats.


2019 ◽  
Vol 100 (4) ◽  
pp. 1263-1273
Author(s):  
Youngsang Kwon ◽  
Anna C Doty ◽  
Megan L Huffman ◽  
Virginie Rolland ◽  
Daniel R Istvanko ◽  
...  

AbstractNorth American bats are experiencing declines in part due to anthropogenic impacts resulting in habitat loss and disturbance. In eastern deciduous forests, bats rely on forest resources for all or part of the year. Therefore, to promote conservation of bats, it is essential to determine whether current forest management techniques are compatible with habitat use by bats. We evaluated the relative effect of landscape characteristics, including forest management variables, on sex-specific foraging habitat of an insectivorous forest-dwelling bat species, the evening bat (Nycticeius humeralis), and predicted areas of suitable habitat for N. humeralis. A total of 18 variables were assessed using a maximum-entropy (Maxent) machine-learning approach: eight land use–land cover classes, three stand types, two topography measures, normalized difference vegetation index, and four forest management variables. Females showed the highest probability of presence closer to stands treated with prescribed fire, whereas males showed the highest probability of presence closer to reforested stands. In general, males exhibited more flexibility than females in their habitat selection. The Maxent model further indicated that habitat associated with suitability of > 70% was ~4 times larger for males than females, and predicted an additional area of suitable foraging habitat where no presence locations had been recorded. Our modeling approach may be suitable for other researchers to derive models appropriate for a wide range of bat species.


The Condor ◽  
2001 ◽  
Vol 103 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Katia Lombardini ◽  
Robert E. Bennetts ◽  
Christophe Tourenq

Abstract We examined habitat use by Little Egrets (Egretta garzetta) and Cattle Egrets (Bubulcus ibis) that nest together in mixed-species colonies in the Camargue of southern France. We explored the relative use of seven habitat types in relation to their availability and tested the hypothesis that selection of habitat types was related to foraging success, with the prediction that increased foraging success in a given habitat corresponded with increased use of that habitat type. Ricefields and other agricultural habitats were used more than expected by Cattle Egrets, an invasive species in southern Europe; whereas Little Egrets, which are native to the Camargue, tended to select natural freshwater marshes and lagoons. Results were consistent with the hypothesis that increasing use of habitats corresponded with higher foraging success for both species. However, when this analysis was restricted to habitats with sufficient numbers of birds to enable estimates of biomass intake, the association was no longer apparent for Little Egrets.


Sign in / Sign up

Export Citation Format

Share Document