Managing Conflict between Bats and Humans: The Response of Soprano Pipistrelles (Pipistrellus pygmaeus) to Exclusion from Roosts in Houses (original) (raw)
Related papers
animal behaviour, 1998
Availability of suitable roost sites may limit bat distribution and abundance. We compared nine internal and 26 external features of 21 known roost buildings with those of 17 random buildings in northeast Scotland, U.K. (57 N) to assess whether pipistrelle bats, Pipistrellus pipistrellus (55-kHz phonotype) are selective in their use of roosts. Bats did not select roosts with specific structural attributes. Compared with random buildings, roosts were closer to a tree over 10 m tall and had a greater percentage cover (of trees over 10 m tall) within a radius of 50 m. Trees may provide benefits by providing shelter and thus ameliorating the microclimate of the roost. Cover may also provide protection from predators so that bats are able to emerge earlier, thus increasing foraging time. Bats in the present study emerged 11 min earlier from roosts with 29% cover than from roosts with 3% cover, potentially gaining as much as 10% of their daily energy requirements in this extra time. Roosts were also more likely to have linear vegetation elements leading away from them. These features may be important for navigation, foraging or predator avoidance. Compared with random buildings roosts were closer to and surrounded by a greater area of deciduous woodland within a radius of 0.5 km, had a greater area of coniferous woodland within a radius of 0.5 km, and were more likely to be found within 0.5 km of a major river. All these factors are likely to be beneficial for foraging. A logistic regression model indicated that percentage cover within 50 m of the building was the best predictor of the presence or absence of bats roosting in a building.
Roost Selection by the Brown Long-Eared Bat Plecotus auritus
Journal of Applied Ecology, 1997
1. One of the key threats to bats in Britain is loss of suitable roost sites, but little is known about roost requirements for most species. 2. Roost selection in the brown long-eared bat Plecotus auritus was demonstrated by comparison of buildings used as summer roosts in northeast Scotland with (i) random buildings in the same area, and (ii) a set of adjacent houses located in the same habitat. 3. Buildings containing roosts were situated closer to woodland and water relative to the random houses, and also had a greater area of woodland within a radius of 0 5 km, but not at distances beyond this. This suggests that feeding habitat in the vicinity of the roost is important for roost selection. 4. When compared with adjacent houses, roosts were older, and had roof spaces divided into more compartments, which were more likely to be fully lined with rough wooden planking. 5. The temperatures inside summer roosts (mean 17 9?C) were significantly warmer than those from random and adjacent houses (mean 16 7?C). 6. These results suggest that P. auritus is selective of its roosts, relative to the houses available. 7. The selection of specific types of roosts by P. auritus has implications for the management advice provided when roosts are threatened, and conservation actions should focus on efforts to avert significant change to, or destruction of, roost sites or the woodland in their vicinity.
Journal of Zoology, 2003
The seasonal activity of Leisler's bat Nyctalus leisleri and pipistrelle bats Pipistrellus spp. with respect to minimum bat numbers and habitat use were investigated in County Down, Northern Ireland using a driven transect from April 1998 to October 1998. Data were collected in lowland farmland near Belfast, Northern Ireland using two BatBox III bat detectors tuned to detect both species and species groups simultaneously. The number of bats/km increased during April, May and June, peaking in July and tailed off after this period. The main peak in July is assumed to reflect the occurrence of newly volant young. An increase in the number of pipistrelle social calls during August and September probably represented mating activity. Bat activity correlated with temperature in both N. leisleri and Pipistrellus spp., although bat numbers were independent of temperature after the middle of June. There was significant variation in habitat use by pipistrelle bats along roads over the study period. Pipistrelle bats were observed in greater numbers in areas of tree-line, cut hedge (<1 m high) and deciduous woodland, and increased further when these habitats bordered both sides of the road. Nyctalus leisleri was found in similar numbers in all habitat types and there was no seasonal variation in habitat use. The validity of this method for revealing seasonal variation in bat numbers and habitat use is discussed. Ambient climatic conditions may affect the number of bats recorded, while some species with long-range echolocation calls, such as N. leisleri, may defy analysis of habitat associations.
Effect of roost size on the emergence behaviour of pipistrelle bats.
Animal behaviour, 1999
We refined established methods for examining the temporal organization of behavioural events and applied them to the study of bats emerging from roost sites. Previous studies have shown that as roosting numbers of bats increase, temporal patterning (clustering) in their emergence behaviour, as measured by 2 or G statistics, also increases. Expressing the extent of temporal clustering using 2 or G, however, confounds two effects. The statistic may increase because clustering increases. However, an increase will occur, even if the amount of clustering stays constant, if the sample size of observations increases. A positive relation between emergence size and 2 or G may not necessarily reflect increased clustering. We developed a method to separate these effects using computer-modelled event streams. Using this method, we examined intra-and inter-roost variation in the temporal patterning of emergences of the pipistrelle bat, Pipistrellus pipistrellus, from four roosts in northeast Scotland. The 'corrected' expression of clustering decreased as roost size increased, which was opposite to the effect found with the uncorrected expression and also opposite that predicted a priori from the bottleneck hypothesis. This novel result suggests bottlenecks may disrupt clustering rather than promote it. This latter interpretation was supported by observations that clustering was significantly reduced in the middle of large emergences. Variation in clustering between roosts was significant, suggesting exit topology may have an important influence on clustering behaviour.
Biological Conservation, 2000
The bat species Rhinolophus hipposideros has undergone a dramatic decline throughout much of western Europe from the 1960s. The mechanisms responsible for this phenomenon have not been conclusively identi®ed. At the same time, some populations of Pipistrellus pipistrellus have increased substantially, possibly as a consequence of foraging upon insects attracted by street lamps. To evaluate whether there might be some ecological link between the opposite demographic trends observed in the two species, we compared the diets of two sympatric populations of R. hipposideros and P. pipistrellus in south-west Switzerland. The two bat species fed upon the same categories of prey, mainly moths and Diptera, and we were not able to recognize interspeci®c dierences in diet composition in spring when resources were most likely to be limiting. Although using dierent foraging strategies, both species may visit the same or adjacent feeding grounds, therefore potentially competing for the same populations of prey. Although conclusive evidence is still needed, bat conservation policy should pay more attention to this possibility. #
2012 Murphy et al Brown long-eared bats and woodland management
Reinstating forestry practices, such as coppicing, thinning the understorey and grazing, has become a key element of proposals for improving the conservation value of broadleaved woodlands in Europe. However, the consequences of such woodland management for bats are poorly understood because of a lack of knowledge concerning their habitat requirements. We studied the brown longeared bat Plecotus auritus in South East England to determine how their patterns of habitat use could inform conservation management. Radio-tracking of 38 adult females showed that they foraged primarily in woodland and that each had a foraging area (mean = 4.4 ha) that they returned to on successive nights. Core foraging areas (mean = 2.1 ha) were characterized by more cover and greater species diversity in the understorey layer than more peripheral areas. Hedgerows were also used for foraging in the late summer and autumn. Most conservation activities for this species have focused on protecting roosts in houses and other buildings. While such protection is important for bat conservation, efforts should also be made to protect foraging habitats in woodlands by maintaining cover of native species in the understorey layer and hedgerows that provide connectivity between woodland patches. Common conservation management practices, such as reinstating coppicing or grazing in semi-natural broadleaved woodlands, could be detrimental for P. auritus and other woodland bats. Their impact on bats should be tested experimentally before they are widely promoted as a woodland conservation strategy.
Geoffroy’s bat (Myotis emarginatus) has four known breeding colonies in the Netherlands. Two of these are the known most northerly maternity roosts of the species. Both colonies have received Natura 2000 status. In order to collect ecological data needed to develop a management plan of these two sites, seven female Geoffroy’s bats from these two breeding colonies were radio tagged and tracked during their foraging trips. The animals used woods, stables of cattle and sheep, and tree lanes, to a distance of up to 8 kilometres from the maternity roosts. The animals used tree lanes to fly from their roosts to the hunting areas, but also to forage. They spent the most time in woods (36%), stables (32%), and in tree lanes (29%), the remaining time (2%) was spent in urban areas, open fields and orchards. We did not observe any movement of individuals between the two colonies. The percentage of the night spent in stables was negatively correlated with outside temperature. Based on the ecolo...