State dependence of arousal from torpor in brown long-eared bats (Plecotus auritus)

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Hvor skal man dra for å ta hvilket byttedyr? Områdebruk, habitat seleksjon og byttedyrfangst hos Perleugle (Aegolius funereus) hanner studert ved bruk av radiotelemetri og videoovervåkning ved reiret.

The home range use and habitat selection of four providing male Tengmalm's owls (Aegolius funereus) were studied by using radio telemetry, and simultaneously recording prey deliveries by a video camera positioned inside the nest box of each nest. The camera allowed prey identi cation and made it possible to assign prey deliveries to locations in the eld, i.e, the last observation x before a delivery. 100% MCP home ranges averaged 219.4 ha, whereas 95% kernel home ranges had a mean size of 310 ha, and decreased with increasing proportion of high productivity areas in the home range. Owls did not shift hunting areas from one night to the next, but rather changed it gradually over time. Habitat selection was estimated by calculating the distance from each observation x (N=458) and from each random plot (N=480) to the nearest patch of each habitat class, and testing for di erences using logistic regression. The owls showed a particularly strong selection for hunting in forest age class I (clear-cuts and plantations), which is the primary habitat of their main prey, Microtus voles. They hunted closer to areas of medium and high productivity, and farther from areas of low productivity and impediment than expected by random. This may be related to abundance and availability of prey animals which select areas of dense vegetative cover. Bogs did not seem to be selected, but due to the low proportion in two of the nests, the results were inconclusive. Male owls both hunted and captured prey closer to the nest than expected by random. Additionally, prey captures were located closer to high productivity and farther from areas of impediment than expected by random. Shrews were captured closer to areas of high productivity than expected by random, which is in accordance with other ndings that suggest that the density of shrews increases with productivity. Shrews seemed to be excluded from certain habitats by Microtus voles because captures of shrews were located farther from forest age class I than captures of Microtus voles. Although the pro tability of transporting prey items back to the nest in theory is related to prey size and distance from the nest, the larger Microtus voles were not transported to the nest from longer distances than the smaller shrews. An owl returned to the area where it captured the last prey more often than expected by random. Thus, the owls utilized a win-stay strategy. The present study is the rst to combine radio tracking and video monitoring to determine habitat speci c prey capture in Tengmalm's owl and highlight the importance of habitat productivity for hunting owls

Hvor skal man dra for å ta hvilke byttedyr? : områdebruk, habitat seleksjon og byttedyrfangst hos perleugle (Aegolius funereus) hanner studert ved bruk av radiotelemetri og videoovervåkning ved reiret

The home range use and habitat selection of four providing male Tengmalm's owls (Aegolius funereus) were studied by using radio telemetry, and simultaneously recording prey deliveries by a video camera positioned inside the nest box of each nest. The camera allowed prey identi cation and made it possible to assign prey deliveries to locations in the eld, i.e, the last observation x before a delivery. 100% MCP home ranges averaged 219.4 ha, whereas 95% kernel home ranges had a mean size of 310 ha, and decreased with increasing proportion of high productivity areas in the home range. Owls did not shift hunting areas from one night to the next, but rather changed it gradually over time. Habitat selection was estimated by calculating the distance from each observation x (N=458) and from each random plot (N=480) to the nearest patch of each habitat class, and testing for di erences using logistic regression. The owls showed a particularly strong selection for hunting in forest age class I (clear-cuts and plantations), which is the primary habitat of their main prey, Microtus voles. They hunted closer to areas of medium and high productivity, and farther from areas of low productivity and impediment than expected by random. This may be related to abundance and availability of prey animals which select areas of dense vegetative cover. Bogs did not seem to be selected, but due to the low proportion in two of the nests, the results were inconclusive. Male owls both hunted and captured prey closer to the nest than expected by random. Additionally, prey captures were located closer to high productivity and farther from areas of impediment than expected by random. Shrews were captured closer to areas of high productivity than expected by random, which is in accordance with other ndings that suggest that the density of shrews increases with productivity. Shrews seemed to be excluded from certain habitats by Microtus voles because captures of shrews were located farther from forest age class I than captures of Microtus voles. Although the pro tability of transporting prey items back to the nest in theory is related to prey size and distance from the nest, the larger Microtus voles were not transported to the nest from longer distances than the smaller shrews. An owl returned to the area where it captured the last prey more often than expected by random. Thus, the owls utilized a win-stay strategy. The present study is the rst to combine radio tracking and video monitoring to determine habitat speci c prey capture in Tengmalm's owl and highlight the importance of habitat productivity for hunting owls. Sammendrag Hjemmeomr adet og habitat seleksjonen til re Perleugle (Aegolius funereus) hanner ble studert ved bruk av radio telemetri, samtidig som byttedyrleveringer ble registrert av et videokamera plassert inni reir-kassen til hvert reir. Kameraopptakene tillot identi kasjon av byttedyr og gjorde det mulig a koble byttedyrleveringer til lokasjoner i felt, i hovedsak siste observasjon f r levering. 100% MCP hjemmeomr a der hadde en gjennomsnittlig st rrelse p~219.4 ha, mens 95% kernel hjemmeomr ader hadde en gjennomsnittlig st rrelse p~310 ha, og minket med kende andel av omr ader med h y produktivitet i hjemmeomr adet. Perleuglene byttet ikke jaktomr a de for hver natt, men skiftet jaktomr a de gradvis over tid. Habitatseleksjon ble estimert ved akalkulere avstanden fra hver observasjon (N=458) og fra hvert random plot (N=480) til n rmeste omr ade av hver habitatkategori, for deretter ateste om det var signi kante forskjeller mellom disse ved bruk av logistisk regresjon. Perleuglene viste en spesielt stor seleksjon for skog i aldersklasse I (hogst ater og plantasjer), som er prim rhabitatet for Perleugles hovedbyttedyr, Microtus. I tillegg jaktet de n rmere omr ader med medium og h y produktivitet, og lenger fra omr ader av lav produktivitet og impediment enn forventet av tilfeldig valg. Dette henger muligens sammen med tallrikhet og tilgjengelighet av byttedyr som foretrekker tett vegetasjonsdekke. Myromr ader s a ikke ut til a bli selektert, men grunnet lav tilgjengelighet i to av reirene var resultatene tvetydige. Hannene jaktet og fanget byttedyr n rmere reiret enn forventet ved tilfeldig valg. I tillegg var fangster av byttedyr lokalisert n rmere omr ader med h y produktivitet og lengre fra omr ader med impediment enn forventet ved tilfeldig valg. Spissmus ble fanget n rmere omr ader med h y produktivitet enn forventet ved tilfeldig valg. Dette stemmer overens med andre funn som indikerer at tettheten av spissmus ker med kende produktivitet. Spissmus s a ut til a bli ekskludert fra enkelt habitat av Microtus fordi fangstpunkter av spissmus var lokalisert lengre fra aldersklasse I enn fangstpunkter av Microtus. Selvom l nnsomheten ved a transportere byttedyr tilbake til reiret er relatert til byttedyrst rrelse og avstand fra reiret, ble ikke Microtus transportert lengre enn spissmus til tross for forskjeller i st rrelsen. Uglene returnerte oftere til forrige fangstomrde oftere enn forventet ved tilfeldig valg. Med andre ord utnyttet Perleuglene en "vinn-bli" strategy. Dette studiet er det frste til a kombinere radio peiling og video overv akning til a fastsl a habitat-spesi kk byttedyr fangst hos Perleugle og belyser viktigheten av habitat produktivitet for jaktende ugler.M-N

Energetics of whiskered bats in comparison to other bats of the family Vespertilionidae

Bats inhabit a variety of climate types, ranging from tropical to temperate zones, and environmental differences may therefore affect the basal metabolic rate (BMR) of bats from different populations. In the present study, we provide novel data on the energetics of whiskered bats (Myotis mystacinus), which is the smallest species within Chiroptera measured to date. We investigated the thermoregulatory strategies of M. mystacinus close to the northern limits of this species’ distribution range and compared these data to other vespertilionid bats living in different climates. As mammals living in colder areas experience elevated thermoregulatory costs, often leading to an increase in BMR, we hypothesised that BMR of this northern population of whiskered bats would be higher than that of bats from climates with warm environmental temperatures. From a systematic literature search we obtained BMR estimates (N=47) from 24 species within Vespertilionidae. Our metabolic measurements of M. mystacinus in Norway (body mass of 4.4 g; BMR of 1.48 ml O2 g−1 h−1) were not different from other vespertilionid bats, based on the allometric equation obtained from the systematic literature search. Further, there was no effect of environmental temperature on BMR within Vespertilionidae. How these tiny bats adapt metabolically to high latitude living is thus still an open question. Bats do have a suite of physiological strategies used to cope with the varying climates which they inhabit, and one possible factor could be that instead of adjusting BMR they could express more torpor

A species-level trait dataset of bats in Europe and beyond

Abstract Knowledge of species’ functional traits is essential for understanding biodiversity patterns, predicting the impacts of global environmental changes, and assessing the efficiency of conservation measures. Bats are major components of mammalian diversity and occupy a variety of ecological niches and geographic distributions. However, an extensive compilation of their functional traits and ecological attributes is still missing. Here we present EuroBaTrait 1.0, the most comprehensive and up-to-date trait dataset covering 47 European bat species. The dataset includes data on 118 traits including genetic composition, physiology, morphology, acoustic signature, climatic associations, foraging habitat, roost type, diet, spatial behaviour, life history, pathogens, phenology, and distribution. We compiled the bat trait data obtained from three main sources: (i) a systematic literature and dataset search, (ii) unpublished data from European bat experts, and (iii) observations from large-scale monitoring programs. EuroBaTrait is designed to provide an important data source for comparative and trait-based analyses at the species or community level. The dataset also exposes knowledge gaps in species, geographic and trait coverage, highlighting priorities for future data collection