Circadian rhythms play a crucial role in the health and survival of organisms. However, little is known concerning how intrinsic and extrinsic factors affect animal daily rhythms in the field, especially in nocturnal animals. Here, we investigated the first emergence, mid‐emergence, and return times of Vespertilio sinensis, and also integrated environmental conditions (temperature, humidity, and light intensity) and biotic factors (reproductive status and predation risk) to determine causes of variation in the activity rhythms of the bats. We found that variation in the first emergence time, the mid‐emergence time, and the final return time were distinct. The results demonstrated that the emergence and return times of bats were affected by light intensity, reproductive status, and predation risk in a relatively complex pattern. Light intensity had the greatest contribution to activity rhythms. Moreover, we first investigated the effects of actual predators on the activity rhythms of bats; the results showed that the mid‐emergence time of bats was earlier as predators were hunting, but the final return time was later when predators were present. Finally, our results also highlighted the importance of higher energy demands during the lactation in bats to variation in activity rhythms. These results improve our understanding of the patterns and causes of variation in activity rhythms in bats and other nocturnal animals. 相似文献
Schreiber’s bent-winged bat Miniopterus schreibersii and the greater horseshoe bat Rhinolophus ferrumequinum are widespread and common cavernicolous species across southern Europe that host numerous specialized ectoparasite species. The objective of this study was to characterize the species assemblage, genetic diversity, and host specificity of bat flies (Nycteribiidae, Diptera) and wing mites (Spinturnicidae, Acari) found on these bat hosts in Serbia and Bosnia and Herzegovina. Notably, while bat flies lay puparia on the cave walls and can thus be transmitted indirectly, wing mites require direct body contact for transmission. Morphological identification and sequencing of a 710-bp fragment of cytochrome oxidase I gene of 207 bat flies yielded 4 species, 3 on M. schreibersii and 1 on R. ferrumequinum. Sequencing of a 460-bp small subunit ribosomal RNA fragment, in all 190 collected wing mites revealed 2 species, 1 per host. In no case was a parasite associated with 1 host found on the other host. Species and genetic diversity of flies were higher in M. schreibersii, likely reflecting their host’s larger colony sizes and migratory potential. Mite species of both hosts showed similarly low diversity, likely due to their faster life history and lower winter survival. Our findings highlight a remarkably high host-specificity and segregation of ectoparasite species despite direct contact among their hosts in the roost, suggesting a defined host preference in the investigated ectoparasite species. Furthermore, the differences in ectoparasite genetic diversity exemplify the interplay between host and parasite life histories in shaping parasite population genetic structure. 相似文献
The Bonin Islands are endowed with endemic species. However, these species are at risk of extinction because of the exuberance of invasive alien plants. Therefore, native plant species should be revegetated after eradicating alien plants. We investigated the genetic variation of Terminalia catappa populations in the Bonin Islands by using nuclear (n) microsatellites (simple sequence repeats [SSRs]) and chloroplast (cp) DNA. No significant differences were observed in the genetic diversity of nSSRs among 22 populations. However, recent bottlenecks were detected in three populations on the Chichijima Island group. nSSR variation and cpDNA haplotypes suggested the presence of two genetically distinct groups in the Mukojima and Chichijima Island groups and the Hahajima Island group. A similar genetic structure was observed in plants and animals in the Bonin Islands. Populations on the three islands, which were separated from other islands in each island group when the water depth was 50‐m lower than the present level, were dominated by unique nSSRs clusters, suggesting that historical changes in island connections during the Pleistocene era affected genetic substructuring. These results suggested that different factors contributed to the genetic structure of T. catappa on different geographic scales. At the whole‐island level, the genetic structure was determined by long‐distance seed dispersal by ocean currents. At the island‐group level, the genetic structure was determined by historical changes in island connections caused by changes in the sea level due to glacial–interglacial transition. These findings would help in establishing transplantation zone borders for revegetating T. catappa on the Bonin Islands. 相似文献
1. 1.|Independent of their diverse feeding habits almost all bats are nocturnal. One hypothesis for chiropteran nocturnality is that bats flying in the day experience fatal hyperthermia because their wings take up significant amounts of short-wave radiation which they are unable to dissipate convectively. Factors that will critically affect a bat's susceptibility to overheating are the albedo and transmittance of wing membranes to short-wave radiation.
2. 2.|Albedo of taut segments of bat wings from four species of insectivorous bats and one Pteropid varied between 0.026 (for Rhinolophus hipposideros) and 0.069 (Plecotus auritus).
3. 3.|Transmittance exceeded albedo in all species studied and varied from 0.077 (Pipistrellus pipistrellus) to 0.194 (P. auritus). In this small sample there was no relationship between albedo and transmittance.
4. 4.|Total absorbed short-wave radiation amounted to between 70 and 92% of the incident radiation, and averaged 81.9% (SE = 2.4%, n = 9). Given a clear sky short-wave flux density of about 971 W · m−2 a typical small insectivorous bat (5g, wing AREA = 0.013 m2, ABSORPTIVITY = 81.9%) with fully outstretched wings and the sun directly overhead would absorb about 10.65 W, compared with the maximum endogenous heat production from flight of 0.83 W.
5. 5.|Predicted maximum exogenous heat load relative to maximum endogenous heat load declined as a function of body mass, however, even in the largest known bats (1.4 kg) the exogenous burden exceeded by a factor of 3 the endogenous heat load.
ABSTRACT We quantified protection given by a variety of gloves against bat bites by using steel indenters to simulate teeth and measuring forces needed to puncture the gloves. Level of protection given by gloves was compared to expected bite forces and tooth sharpness of bats. Cotton, plastic-coated synthetic fabric, and proprietary materials advertised as puncture- and cut-resistant were easy to penetrate compared to leather gloves. Split leather gives the highest level of protection, but with reduced dexterity. These are best for handling larger bats (>40 g) or if higher safety is preferred. Deerskin gives reasonable protection without much loss in dexterity for handling bats <40 g. 相似文献
A one‐year phenological study of three columnar cacti, Stenocereus griseus (Haw.) Britton & Rose, Pilosocereus sp., Cereus hexagonus (L.) Mill., and a decumbent cactus Monvillea cf. smithiana (Britton & Rose) Backeberg., was carried out in the Andean arid region of La Tatacoa, Colombia. Pollinators and/or dispersers of the cacti species also were studied monthly, and fecal samples were collected for the identification of pollen and seeds. The flowering of all species was prolonged and showed bimodal, multimodal, or irregular patterns. Fruiting in all species also was prolonged and followed flowering with a lag of less than two months. Although there were no simple correlations between rainfall and flowering or fruiting, flower production during the dry season was higher for 5. griseus, while Pilosocereus sp. and C. hexagonus showed higher flower production during the wet season. Fruit production was also seasonal, with higher production during the wet season for 5. griseus and C. hexagonus. The patterns of flowering and fruiting in M. cf. smithiana showed no relationships with dry and wet seasons. The bats Glossophaga longirostris, Carollia perspicillata, Sturnira lilium, the birds Melanerpes rubricapillus (Picidae) and Mimus gilvus (Mimidae), and moths of the family Sphingidae, were identified as pollinators and/or fruit consumers of these cacti species. 相似文献