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1.
Katherine L. Boughey Iain R. Lake Karen A. Haysom Paul M. Dolman 《Biological conservation》2011,(9):2300-2310
Although forest fragmentation can greatly affect biodiversity, responses to landscape-scale measures of woodland configuration in Europe have been examined for only a limited range of taxa. Almost all European bat species utilise woodland, however little is known about how they are affected by the spatial arrangement of woodland patches. Here we quantify landscape structure surrounding 1129 roosts of six bat species and a corresponding number of control locations across the UK, to examine associations between roost location and landscape composition, woodland proximity and the size of the nearest broadleaved woodland patch. Analyses are performed at two spatial scales: within 1 km of the roost and within a radius equivalent to the colony home-range (3–7 km). For four species, models at the 1 km scale were better able to predict roost occurrence than those at the home-range scale, although this difference was only significant for Pipistrellus pipistrellus. For all species roost location was positively associated with either the extent or proximity of broadleaved woodland, with the greatest effect of increasing woodland extent seen between 0% and 20% woodland cover. P. pipistrellus, Pipistrellus pygmaeus, Rhinolophus hipposideros, Eptesicus serotinus and Myotis nattereri all selected roosts closer to broadleaved woodland than expected by chance, with 90% of roosts located within 440 m of broadleaved woodland. Roost location was not affected by the size of the nearest broadleaved patch (patches ranged from 0.06–2798 ha ± 126 SD). These findings suggest that the bat species assessed here will benefit from the creation of an extensive network of woodland patches, including small patches, in landscapes with little existing woodland cover. 相似文献
2.
Bat activity and benthic macroinvertebrates were sampled at nine paired sites, upstream and downstream from sewage effluent discharges into Irish rivers. Bat activity was measured using broadband acoustic detectors and macroinvertebrates by three 30-s standard benthic kick samples per site. Biological indices of water quality were significantly lower downstream from sewage outfalls, relative to upstream. The soprano pipistrelle (Pipistrellus pygmaeus) was significantly more active (as measured by bat passes per unit time) at downstream sites, while Daubenton’s bat (Myotis daubentonii) was less active. These results contrast with those of a similar study in England, where P. pygmaeus were less active, and Myotis spp. were more active downstream from sewage outfalls. We suggest that P. pygmaeus were more active downstream in our study because of a preference for preying on small orthocladiinid Chironomidae (non-biting midges), which were significantly more abundant downstream. M. daubentonii may prefer Trichoptera (caddis fly), which were significantly more abundant upstream. Organic pollution may then affect bats, but its effect appears to be more complex than previously implied. Implications of changing nutrient levels in freshwaters for populations of M. daubentonii and P. pygmaeus may be different from what is currently suggested in the literature. 相似文献
3.
We investigated the extent of visitation of underground sites during late summer and autumn (‘swarming’) by bats. Bats were captured at eight cave, mine and tunnel sites in southern England over 6 years (1995-2000). A total of 3077 bats representing 11 of Britain's 16 species was caught. Myotis bats predominated in autumn. At some sites these are rarely seen during winter hibernation counts. Myotis nattereri and M. daubentonii were most common. However, species composition changed seasonally. At one site, M. brandtii dominated early in the season and at all sites peak activity of M. daubentonii was earlier than in M. nattereri. Relatively high numbers of internationally vulnerable species such as M. bechsteinii and Barbastella barbastellus were recorded. There was a strong male bias in captures of swarming species. Swarming probably has an important reproductive function, most males are reproductively active at this time and such sites may be important for outbreeding. Due to this and the large number of individuals and species concerned, the conservation of ‘swarming sites’ is vitally important. Clearly swarming sites merit special consideration in conservation management strategies for cave-dwelling bats. 相似文献
4.
To conserve the foraging habitat of Daubenton’s bat (Myotis daubentonii) in a large lowland river, we investigated the influence on this bat of prey variables (number or biomass) and insect origin (aquatic or terrestrial). We tested the hypothesis that river restoration (re-meandering) conducted in the Shibetsu River, northern Japan, enhances foraging habitat quality by increasing the abundance of aquatic insects. From June to September 2004, flying insects were collected using Malaise traps in restored and channelised reaches in the Shibetsu River. Bat activity was recorded by bat detectors placed near the Malaise traps in each of the two reaches. Foraging activity of Daubenton’s bat was more strongly related to the number of insects than to biomass, and to adult aquatic insects than to terrestrial insects. The high dependence of Daubenton’s bat on aquatic prey was attributed to the fact that aquatic insect numbers were always higher than those of terrestrial insects. Contrary to the hypothesis, Daubenton’s bat was more active in the channelised reach than the restored reach in all months except June, and it synchronized its foraging activity with the seasonal distribution of adult aquatic insects. However, the study was undertaken just two years after restoration and the riparian vegetation had not yet established itself. Our results demonstrate the importance of aquatic insect abundance for Daubenton’s bat throughout the seasons in large lowland rivers. A further decrease in aquatic insects, associated with progressive anthropogenic alteration of river environments, undoubtedly exerts a harmful influence on the conservation of this species. 相似文献
5.
The roosts of many IUCN-listed cave-roosting bat species are under threat from tourist development in SE Europe and other regions of the world. Much-needed conservation strategies require, among other information, an understanding of their roost movements and population dynamics, which can now be obtained relatively quickly using advanced models. We have studied the long-fingered bat, Myotis capaccinii, an obligate cave-dweller, in Dadia National Park, Greece. The species formed colonies of up to a few thousand individuals and was highly mobile, frequently switching summer roosts up to 39 km apart, even during late pregnancy. The bats migrated to distant hibernacula including a cave in Bulgaria 140 km NW of the Park. Adult recapture probabilities varied with season and sex: low female recapture rates in autumn, relative to spring and summer, indicated non-random temporary emigration following nursery colony dispersal. The opposite pattern was seen in males: increasing recapture rates in the autumn suggest that males gather in these roosts to mate with females in transit. Adult survival (0.86-0.94) was similar in females and males, similar in winter and summer, and comparable to recent estimates for other bats based on similar modelling techniques. Sex-based differences in juvenile recapture suggest female philopatry and male-biased dispersal. Our work shows that protection of M. capaccinii roosts must extend beyond the Park’s and indeed the country’s boundaries: its conservation requires large-scale, trans-national integrated conservation plans. Our results will apply to many other warm-temperate species with similar life history cycles. 相似文献
6.
Anita M. Glover 《Biological conservation》2008,141(6):1493-1504
Caves are an important resource to a large proportion of temperate bat species, primarily as mating and hibernation sites. However, information on bat use exists for only a small fraction of caves in many parts of the temperate world, in part because current survey methods are inappropriate for many species. We surveyed the UK’s largest karst landscape, the Yorkshire Dales, by monitoring autumn swarming (mating) activity at 53 caves using automated echolocation call loggers, followed by trapping. Over 60% of caves surveyed were used by bats, but there was considerable variation in activity. Swarming activity was positively correlated with chamber development and negatively correlated with the amount of water the cave carried: together these two predictors explained 45% of the variance. Entrance orientation and shelter explained a further 10%. Activity was not correlated with entrance size, altitude or connectivity to the nearest summer habitat. All five resident swarming species were caught at most sites: Myotis brandtii, Myotis daubentonii, Myotis mystacinus, Myotis nattereri and Plecotus auritus. Behaviour, species composition and sex and age ratios were typical of swarming reported in other studies. Bat populations and catchment sizes were large and despite the proximity of other suitable caves, bats showed high fidelity to single sites. Our results show that the national importance of these caves has been overlooked. We suggest that survey for swarming activity is a quick and effective method of identifying underground bat sites and is likely to uncover many previously unknown and important sites throughout the temperate world. 相似文献
7.
Many species of temperate bats visit underground sites in autumn, prior to hibernation, and chase each other in and around the entrances in an event known as autumn swarming. It has been suggested that swarming is a mating event that facilitates gene flow between bats from otherwise isolated summer colonies. We describe swarming behaviour at a cluster of four caves in the North of England and provide direct evidence for seasonal migration of Natterer’s bats (Myotis nattereri ) between these caves and many summer nursery roosts in a catchment area of at least 60 km radius. Mark-recapture analysis suggests that an estimated 2000-6000 Natterer’s bats use the three best-studied caves, together with smaller numbers of four other species: M. daubentonii, M. brandtii, M. mystacinus and Plecotus auritus. Recaptures also show that there is a small interchange of bats between these three caves, which are 0.6-1.5 km apart. Capture rates, automatic logging and video recordings at one cave suggest that an average 310-400 bats visit the cave each night. Mating at swarming sites would be particularly important for gene flow if a species showed no other dispersal pattern. We provide evidence for natal philopatry, with little or no dispersal, in both sexes of Natterer’s bats. The protection of swarming sites is discussed in light of our findings. 相似文献
8.
The distribution and abundance of cave-dwelling bats were investigated in the Thrace region of northwest Turkey. Data were collected in two periods, January-March and April-May 2001, from 32 underground sites, 25 of which had not been surveyed previously. Approximately 76,000 bats representing 13 species were recorded. The most abundant species were Miniopterus schreibersii, Rhinolophus euryale, Myotis myotis/blythii, Myotis capaccinii, and Rhinolophus ferrumequinum. The roosts were evaluated for their conservation importance. The most important sites in Turkish Thrace are Dupnisa and Koyunbaba. The Dupnisa Cave serves as a hibernaculum to approximately 28,000 bats representing five species. The Koyunbaba Cave is a nursery roost to approximately 23,000 bats of six species. Presently, none of the caves in the region has adequate protection and some bat populations are under serious threat. 相似文献
9.
10.
Conserving biodiversity in agricultural landscapes is an urgent issue. The effective conservation of biodiversity requires plans based on species’ habitat preferences at multiple spatial scales. We examined how the foraging habitat selection of bats varied with grain size (50, 150, 250, and 350 m) and how habitat selection in the home range differed from that in the foraging habitat in an agricultural landscape. Focusing on three sympatric Myotis species (Myotis petax, Myotis gracilis, and Myotis frater), we radio-tracked 10 individuals of each species for 121 nights in Hokkaido, northern Japan. Rivers and broadleaved riparian forests were commonly preferred at multiple scales, although the preferred land-cover type was dependent on both extent and grain size for most species. The best grain sizes for predicting the foraging-habitat use of M. petax and M. gracilis were 50 and 150 m. By contrast, M. frater showed no tendency across the grain sizes. Our results indicate that it is necessary to consider both extent and grain size to understand the habitat selection of bats. Our findings also suggest that focusing primarily on preferred land-cover types at multiple scales is effective for conservation planning, given the limited resources in terms of time, manpower, and finances. Although arable did not negatively affect the selection of foraging habitats and home ranges in these bat species, preventing the loss of rivers and forests should be prioritized over preventing arable land expansion. 相似文献
11.
Differences in alpha and beta bat diversity among montane rainforest and five shaded coffee plantations under different management regimes, as well as some environmental factors and vegetation parameters influencing bat richness, were evaluated for the first time in southeastern Chiapas, Mexico. In each site, bats were captured every 2 months from March 2004 to July 2005, with six mist-nets, during two nights, using the capture-recapture method. We captured 2970 individuals of 43 bat species. Montane rainforest had the greatest alpha diversity (H′ = 2.681; n = 37), whereas alpha diversity was similar among coffee plantations (H′ = 2.229-2.364; n = 23-26). The number of frugivorous and nectarivorous species was similar among the sites; the greatest exchange in species composition (beta diversity) occurred for insectivorous bats, which reduce their number in coffee plantations as pesticides are incorporated. Bat richness species was significantly related to the number of vegetation strata, height, and cover of trees. We suggest that coffee plantations could act as corridors, facilitating connection among different elements of the landscape in the Sierra Madre de Chiapas for some frugivorous and nectarivorous bats. 相似文献
12.
Protection of roosting habitat is essential to the conservation of bats in human-dominated landscapes. To help define bat roosting needs in suburban settings, we used radio telemetry to locate day roosts of a common North American species (Myotis yumanensis) within a residential area in California. Between June and August 2000, we tracked 16 bats to 20 roosts in two buildings and 18 trees. We used multiple logistic regression to assess roost selectivity at multiple spatial scales. Of 15 tree, plot, and site characteristics considered, only three helped distinguish roosts from random comparisons: tree diameter, distance to water, and forest cover. Myotis yumanensis preferred large trees (mean diameter 115 cm), and roosted only in the five species of largest mean diameter (Sequoia sempervirens, Pseudotsuga menziesii, Quercus agrifolia, Quercus lobata, and Acer macrophyllum). At the site level, these bats selected roosts that were close to water and had substantial forest cover in the surrounding 100-m radius. Unlike other North American bats, they often roosted in live trees (89% live). Relatively high roost fidelity (mean 4.8 days) and large travel distances between consecutive roosts (mean 1130 m) and between capture sites and roosts (mean 2007 m) may indicate a greater degree of roost limitation at this site versus other research sites. We recommend the preservation of large trees and forested parkland, particularly along stream corridors, to help maintain bat populations in urbanizing landscapes. 相似文献
13.
We actively sampled the bat community at 63 sites using detection and non-detection metrics on the Fernow Experimental Forest (FEF) in the central Appalachians of West Virginia using Anabat acoustical equipment May-June 2001-2003 to relate species presence to simple habitat measures such as proximity to riparian areas, forest canopy cover, forest canopy gap width, and forest canopy height. We acoustically detected eight species on the FEF, including the endangered Myotis sodalis. The presence of Lasiurus cinereus, M. lucifugus, M. sodalis, and Pipistrellus subflavus was associated more with riparian areas than upland areas. Both univariate comparisons and multiple logistic regression modeling showed that the probability that clutter-adapted foraging species such as M. septentrionalis and M. sodalis would be detected was greater as forest canopy cover increased or forest canopy gap size decreased, whereas the opposite was true for open-adapted foraging species such as Eptesicus fuscus and L. cinereus. The overall proportion of unidentifiable bat echolocation sequences to those identified to species was related to upland sites with increasing forest canopy cover indicating some sampling bias between cluttered and uncluttered habitats. However, given sufficient sample points, bat community surveys using acoustical detection show the ability to quickly develop generalized habitat associations for rugged areas such as the central Appalachians where traditional mist-net survey efforts often are logistically difficult and are lacking in scope. Moreover, these acoustical surveys also could lend themselves to species-specific predictive mapping of foraging habitat as well as allowing researchers to formulate testable hypotheses about detailed bat habitat relationships to be definitively tested with radio-telemetry techniques. 相似文献
14.
Forest fragmentation by the expansion of human activities is acknowledged as an important factor driving declines of forest species worldwide and quantitatively characterizing this trend is essential to understanding the response of populations of forest-dependent species. To examine the impacts of forest cover loss and changes in composition on forest-dependent bats, we examined the effects of these factors on the distribution of the northern long-eared bat (Myotis septentrionalis) in a case study. We surveyed forest fragments in the forest-agricultural landscape of Prince Edward Island, Canada, to assess the occupancy of bats in fragments. Logistic regression and multimodel inference using Akaike’s information criteria were used to identify potentially important predictor variables influencing the distribution of the northern long-eared bat at the fragment and landscape level and quantified their effects. A compositional variable, area of deciduous stands, was found to be the best predictor of the presence of M. septentrionalis. We found the effects of fragmentation were greatest at the fragment level for females and at the landscape level for males. This case study emphasizes the importance of examining intra-specific resource selection in how it affects the response of a forest-dependent species to fragmentation. 相似文献
15.
Plants of the Brassicaceae contain glucosinolates, the hydrolysis products of which inhibit the growth of many soil-borne fungi that cause plant disease. However, amending soil with green manures of these plants gives inconsistent control of several soil-borne diseases, including those caused by Rhizoctonia solani. To identify factors that contribute to this inconsistency we investigated, in the laboratory and in pot experiments in the glasshouse, the saprophytic behaviour of R. solani AG2-1 (ZG5) in a sandy soil amended with various green manures. Fresh material from either Brassica napus var. Karoo, B. napus B1, B. napus B2, B. nigra, Diplotaxis tenuifolia (a brassicaceous weed) and the non-Brassicaceae species, oat (Avena sativa) or lupin (Lupinus angustifolius) was used at 10 or 100 g of fresh material kg−1 of dry soil in Lancelin sand. At 100 g kg−1 the volatiles of all green manures reduced the hyphal growth of R. solani, except for B. napus B1. D. tenuifolia at 100 g kg−1 inhibited the growth and sclerotial formation of R. solani. Most green manures at 10 g kg−1, and at 40% water holding capacity, stimulated the growth of R. solani for up to 3 months and increased the activity of other microbes. R. solani infected the brassicaceous plants when growing and colonized the residues mixed with soil at 10 g kg−1. This inoculum increased the severity of damping-off in canola, by 27%. Disease was particularly severe when the green manure species, except D. tenuifolia and oat, were grown in situ and residues returned to the pot from which they came, before sowing canola. There is a potential hazard in applying green manures of Brassica species as their residues can, under certain conditions, support the saprophytic activity of R. solani which increases damping-off in canola sown in the amended soils. 相似文献
16.
Graeme R. Finlayson Emerson M. Vieira Robert Wheeler Chris R. Dickman 《Biological conservation》2008,141(1):320-331
Knowledge of the habitat requirements of threatened species at both local and landscape scales is crucial for maintaining viable populations and for making conservation and management decisions. Here, we use live trapping and radio-tracking to investigate habitat use by four species of threatened marsupials - burrowing bettongs (Bettongia lesueur), brush-tailed bettongs (B. penicillata), greater bilbies (Macrotis lagotis), and bridled nailtail wallabies (Onychogalea fraenata). The study populations had been re-introduced to Scotia Sanctuary in western New South Wales, Australia, within a predator-proof area. All showed preferences for particular macrohabitats while resting by day, with M. lagotis and B. penicillata selecting Eucalyptus woodland with Triodia understorey and B. lesueur and O. fraenata selecting Eucalyptus woodland with shrubs. However, they showed no such partiality at night. Bettongia penicillata used areas with Triodia and litter but few herbs for shelter, while burrows of M. lagotis avoided shrubs. Habitat components that influenced trap captures were: crust cover and herb layer cover (negative) for B. penicillata, trees <5 m in height and number of shrubs (both negative) for B. lesueur, crust cover for M. lagotis, and crust cover and trees <5 m high for O. fraenata (both negative). There was also a negative association at this scale between B. penicillata and both B. lesueur and M. lagotis, suggesting the possibility of competition. Our results support the idea that studies at multiple spatial scales are crucial to understand the habitat use and requirements of threatened fauna, and should therefore be incorporated into future re-introduction programs. 相似文献
17.
Invasive alien plants constitute a major threat to local biodiversity. Moreover, their appearance often coincides with land use change. Many endangered groups of organisms suffer from habitat loss, which is often a consequence of the invasion of alien plants. This paper examines how invasive alien goldenrods Solidago spp. affect the richness of endangered grassland bird species and numbers of breeding pairs in abandoned meadows in southern Poland. Meadows invaded by goldenrods (n = 15) had lower bird species richness and a lower number of breeding pairs than meadows in which goldenrods were absent (n = 15). Two important factors positively influencing bird species richness were meadow area and shrub density (the latter only in meadows without goldenrods). Moreover, both the index of potential food density (number of butterflies) and plant species richness were much lower in meadows invaded by goldenrods than in meadows without these plants. Urgent action aimed at preventing the invasion of alien goldenrods in abandoned meadows is needed and such measures should involve regular mowing. Our results also highlight the fact that land abandonment in Central and Eastern Europe is not necessarily as beneficial for biodiversity as it is commonly believed and it may even lead to a decrease in the populations of several bird species in the agricultural landscape. 相似文献
18.
Dendrobaena mrazeki is an endemic earthworm species inhabiting dry habitats such as pine and thermophilous oak forests in Central Europe. Metabolically, D. mrazeki showed some features typical for endogeic species and some of epigeic ones. In comparison with the related Dendrobaena octaedra, D. mrazeki was a larger earthworm with fresh body mass of adult and subadult individuals of W = 0.59 ± 0.05 g. Its body mass-specific oxygen consumption (M/W = 48 ± 5 μl O2 g?1 h?1, at 15 °C) was the lowest of all earthworms studied (Aporrectodea caliginosa, Aporrectodea rosea, D. octaedra, Lumbricus castaneus, Lumbricus rubellus and Octolasion lacteum), being strongly dependent on W (b from the equation M/W = aWb about ?0.8). D. mrazeki had low relative water content (77.4% of fresh body mass) and small relative amount of dry weight of the intestinal content (20.1% of dry body mass), which is similar to the epigeic D. octaedra. The respiration rate of D. mrazeki remained the lowest even after recalculating M/W to respiration rate per dry mass or per dry mass without the intestine content to correct for the differences among species in body water content and gut content. 相似文献
19.
Echinocactus platyacanthus is a candy barrel cactus endemic to Mexico and an endangered species owing to its exploitation and the destruction of its habitat. The population dynamic of this species is analyzed using matrix models. Three consecutive censuses were carried out (1997, 1998, and 1999) for six populations of this species in the Tehuacán-Cuicatlán Biosphere Reserve. Fruit contain many seeds (mean = 171 ± S.E. 11.03 seeds/fruit); seedling establishment and survival are low (2 × 10−6), and fecundity increases as the diameter of the individuals increases (62 seeds in adult 1-4322 in adult 4). The rates of population growth (λ) range from 0.9285 to 1.0005. Elasticity values for demographic processes indicate that the stasis of the adults is the greatest contribution (S = 0.982), followed by growth (G = 0.017) and fecundity (F = 0.001) to λ. The populations are located in the lower left corner of the demographic triangle; however, there are variations for a given population from one year to the next. Life table response experiments indicate that although there are local variations, the most important differences in the values of λ between populations and between years are associated with changes in the stasis of the adults. The disturbance index is not directly related to population density or to the current value of λ. The protection of adult E. platyacanthus must be taken into account for the management of this species and its conservation in the study area. 相似文献
20.
Cryptic species are similar in morphology, and make interesting subjects for relating morphological differentiation to ecological resource partitioning. Can species that are morphologically almost identical occupy different ecological niches, and hence potentially need distinct conservation planning? The discovery that the most widespread bat in Europe - the pipistrelle - comprised two cryptic species (Pipistrellus pipistrellus and Pipistrellus pygmaeus) that emit echolocation calls at different frequencies provides a remarkable model system for investigating links between morphology, echolocation call design and resource partitioning. We investigated resource partitioning between the two cryptic species of sympatric pipistrelle bats by radio tracking breeding females. Habitat selection was investigated by using compositional analysis. P. pygmaeus selected riparian habitats over all other habitat types in its core foraging areas, whereas P. pipistrellus, although preferring deciduous woodland overall, was more of a generalist, spreading its foraging time in a wider range of habitats. Although morphologically very similar, the cryptic species show quite different patterns of habitat use. Our findings suggest that large-scale differences in habitat preferences can occur between sympatric bat species that are virtually identical in flight morphology; hence morphological differences may be a weak indication of ecological differences between taxa. Conservation planning needs to take account of these differences to meet policy and legal obligations associated with these protected cryptic species. 相似文献