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1

Selection of maternity roosts by Myotis bechsteinii (Kuhl, 1817) in the Southwestern Iberian Peninsula

100%
Napal M., Garin I., Salsamendi E., Aihartza J.
Acta Chiropterologica
|
2009
|
tom 11
|
nr 2
Bechstein’s bat (Myotis bechsteinii) is a European species, restricted to woodlands with preference for mature deciduous forests in lowlands. It is considered rare throughout its range, although it may be common in optimal habitats. Roosts play crucial roles in the ecology of bats, and survival is partially dependant on the extent to which roosts protect bats from environmental extremes and predators. Roost selection is especially important for reproductive females, due to the higher energetic demands imposed by reproduction so understanding roost selection by maternity colonies is important for conservation. We investigated maternity roost selection by M. bechsteinii in southwestern Spain as a hierarchical process that proceeds from broad landscape scales to fine-scale local habitat characteristics. Radio-tracking of 28 lactating females allowed location and census of 13 maternity roost sites. Roosts were characterised at four detail scales (cavity, tree, stand, and landscape). All the roosts occurred in Quercus pyrenaica trees, within stands of the same species of very diverse structure. Ten of the roosts were former woodpecker holes, among which seven had their entrance modified by nuthatch. Roosts were located inside the forest and close (< 620 m) to permanent water sources. Roost trees were characterised by a higher proportion of dead branches. Other explored variables such as tree height, orientation, foliar cover, and elevation did not explain distribution of roosts at any scale. The species’ breeding roost selection is described for the first time in a Mediterranean area.
2

Review on the geographic and elevational distribution of the mountain long-eared bat Plecotus macrobullaris, completed by utilising a specific mist-netting technique

100%
Alberdi A., Garin I., Aizpurua O., Aihartza J.
Acta Chiropterologica
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2013
|
tom 15
|
nr 2
The mountain long-eared bat, Plecotus macrobullaris, is a recently described species, and characterisation of its geographic and elevational distribution is still in progress. Captures in various environments led to a controversial ecological perception, with P. macrobullaris initially defined as an alpine species but subsequently found in the Mediterranean seashore and other lowland areas. Sampling efforts hitherto were uneven; this bat has been studied more thoroughly in Western Europe than in the eastern portion of its range, and in lowlands more than highlands or alpine environments. For greater insight into its distribution pattern, we conducted a field survey in several mountain areas of its known range, using a novel mist-netting technique (described herein) that has proven very useful for targeting and capturing low-flying open-space bats in alpine environments. We also gathered all available distribution data on this species from published resources and by contacting researchers, obtaining records at 351 total localities (including 113 from other authors' unpublished reports and 45 from our own fieldwork). We concluded that P. macrobullaris is present in the main Western Palearctic mountain ranges, extending from the Pyrenees to the Middle East, and has an elevational distribution from sea level up to 2,800 m. The high number of these bats captured foraging above the timberline, in addition to the exclusively mountainous distribution, indicate that the species is indeed alpine, showing a pattern similar to other highly mobile vertebrates restricted to mountain areas and absent from flatlands. Nevertheless, its apparent elevational distribution may still be biased toward lower areas, due to the scarcity of surveys in high mountain habitats.
3

Habitat selection and spatial use by the trawling bat Myotis capaccinii (Bonaparte, 1837)

88%
Almenar D., Aihartza J., Goiti U., Salsamendi E., Garin I.
Acta Chiropterologica
|
2006
|
tom 08
|
nr 1
Habitat selection and spatial use was studied in a population of Myotis capaccinii (Bonaparte, 1837) in the eastern Iberian Peninsula during the spring of 2004. The radio-tracked bats used only aquatic habitats as foraging sites, and most foraging activity concentrated on rivers. Rivers were positively selected and showed the highest preference rank. Pools were also positively selected but only a single pool was used through the tracking period. Foraging was not evenly distributed along rivers. The features of the water surface further determined habitat selection. Open waters with smooth surfaces were selected over cluttered surfaces or waters completely covered by vegetation. This microhabitat preference is thought to be due to a greater efficiency in prey detection and capture over open calm waters. Nonetheless, the extremely high aggregation of foraging individuals observed suggests that the distribution of prey might also affect the location of foraging sites along rivers. Thus, conservation management of M. capaccinii should ensure protection of low-flowing or stagnant waters in rivers around the bats' main caves.
4

Fishing behaviour in the long-fingered bat Myotis capaccinii (Bonaparte, 1837): an experimental approach

88%
Aihartza J., Almenar D., Salsamendi E., Goiti U., Garin I.
Acta Chiropterologica
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2008
|
tom 10
|
nr 2
To study the fishing behaviour of Myotis capaccinii, we performed an experiment in a flight tent containing an artificial pond. We recorded the behaviour of two groups of bats — eight individuals from two different roosts — using IR video camcorders and ultrasound detectors, and evaluated diet by analyzing faeces. Nightly, increasing amounts of fish were released in the pond. Our data show that M. capaccinii is able to exhibit fishing behaviour when fish occur in high densities in shallow waters, gaffing live fish from the water using their hind feet. They were attracted neither by dead fish floating, nor by ripples made by fishes feeding on the water surface. Bats showed a specific fishing behaviour with two main foraging patterns: A) long series of circular flights, skimming along the water and dipping in softly twice or three times in each roundabout; B) long figure-eight loops with bats flying faster and higher, swooping down on the centre of the pond, where they snapped their hind feet hard into the water. Compared with the echolocation calls used to catch insects from the water's surface in the wild, terminal buzzes were incomplete during the dips made to fish. Buzz II were always lacking, and buzz I had much longer inter-pulse intervals. This suggests that they were not pursuing specific targets but dipping randomly. We propose a scenario in which fishing behaviour occurs in the wild, linked to the seasonal drought of small ponds, marshes, or channels where large numbers of small fish become readily available and thus a profitable resource.
5

Foraging ecology in Mihely's horseshoe bats: Influence of habitat structure and water availability

76%
Salsamendi E., Arostegui I., Aihartza J., Almenar D., Goiti U., Garin I.
Acta Chiropterologica
|
2012
|
tom 14
|
nr 1
The climate in Mediterranean ecosystems is characterised by aestival hot temperatures and water shortages which may affect the behaviour of bats living in these environments. We evaluated the influence of habitat type, habitat structure, and water availability on the foraging behaviour of the Mehely's horseshoe bats (Rhinolophus mehelyi) using classification and regression tree (CART) analysis. Twenty-five individuals were successively radio-tracked during May and June in two colonies (Marias and Aurora) of south-western Spain. Twelve females were tracked in Marias and 13 males in Aurora. Both localities differed in the availability of habitat types: in Marias savannah-like oak woodland dominated the landscape (81% of the study area), whereas in Aurora pasture were dominant (64% of the area). Rhinolophus mehelyi always foraged in woodland; preferentially in cluttered spaces, but also in less-cluttered/more-open ones, while open spaces were completely avoided. Bats foraged close to water bodies, preferentially at distances below 500 m, where they may readily have access to drinking water or may encounter higher insect abundances. The similarity between sexes on the preferences of habitat structure and distance to water suggest that the disparity in the habitat types used by males in Aurora and females in Marias may be due to local availability. Riparian forest is an important habitat for foraging and commuting, and should be scrupulously protected. Conservation strategies should also include the protection of woodland of diverse structure and linear landscape elements. We recommend the creation of water bodies in woodlands to enhance the suitability of foraging sites that might be underused.
6

Diet and prey selection in Mehelyi's horseshoe bat Rhinolophus mehelyi (Chiroptera, Rhinolophidae) in the south-western Iberian Peninsula

76%
Salsamendi E., Garin I., Almenar D., Goiti U., Napal M., Aihartza J.
Acta Chiropterologica
|
2008
|
tom 10
|
nr 2
We studied diet and prey selection in Mehelyi's horseshoe bats Rhinolophus mehelyi in the south-western Iberian Peninsula, during the breeding seasons of 2003, 2006, and 2007. Faecal pellets were collected individually and arthropod fragments identified to family level, where possible. Arthropod availability was assessed using Malaise traps. Selection analyses were performed using Compositional Analysis and a Chi-square goodness-of-fit test. The bulk of the diet of R. mehelyi consisted of Lepidoptera, representing more than the 80% of the consumed volume on average (excluding juveniles), and more than 90% of the average percentage occurrence. This pattern was consistent across localities. Neuroptera and Tipulidae were locally abundant. Other important prey categories were Chrysomelidae, Brachycera, and Chironomidae. ANOVA tests showed that there were no significant differences between males and females in consumed prey categories, whereas juveniles consumed significantly less Lepidoptera than adults. Lepidoptera was the first prey category in the preference rank, followed by Myrmeleontidae, Chrysopidae and Tipulidae, and all of these were consumed more than expected by chance. This work shows that R. mehelyi is a moth specialist and suggests that juveniles may acquire this strategy while gaining hunting experience. Given the similarities in echolocation call characteristics and diet in the sibling R. mehelyi and R. euryale, they may compete for trophic resources in sympatry. Nevertheless, subtle differences in wing morphology between both species are probably large enough to permit spatial resource partitioning.
7

Home ranges of European mink Mustela lutreola in Southwestern Europe

76%
Garin I., Zuberogoitia I., Zabala J., Aihartza J., Clevenger A. P., Rallo A.
Acta Theriologica
|
2002
|
tom 47
|
nr 1
We radiotracked 7 European mink Mustela lutreola Linnaeus, 1761 (5 males and 2 females), to determine their distribution, size and temporal changes of their home range in an area of southwestern Europe, where American mink M. vison was not established. Size of home ranges varied from 11 to 17 km along watercourses in males and were 0.6 and 3.6 km in females. Home ranges of males were larger than those found in previous studies. Most females captured (either radiotracked or not) were found within the home range of males. Males occupied adjoining river sections with minimal range overlap, suggesting an intrasexually exclusive spacing pattern for males. Each month males used new river stretches, mainly along tributaries; meanwhile they showed a steady use of their stem river section. Resting sites were mainly beneath dense brambles of Rubus patches located in the river bank.
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