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Aptos, CA, United States

Buchalski M.R.,Western Michigan University | Fontaine J.B.,Murdoch University | Heady III P.A.,Central Coast Bat Research Group | Hayes J.P.,University of Florida | Frick W.F.,University of California at Santa Cruz
PLoS ONE | Year: 2013

Wildlife response to natural disturbances such as fire is of conservation concern to managers, policy makers, and scientists, yet information is scant beyond a few well-studied groups (e.g., birds, small mammals). We examined the effects of wildfire severity on bats, a taxon of high conservation concern, at both the stand (<1 ha) and landscape scale in response to the 2002 McNally fire in the Sierra Nevada region of California, USA. One year after fire, we conducted surveys of echolocation activity at 14 survey locations, stratified in riparian and upland habitat, in mixed-conifer forest habitats spanning three levels of burn severity: unburned, moderate, and high. Bat activity in burned areas was either equivalent or higher than in unburned stands for all six phonic groups measured, with four groups having significantly greater activity in at least one burn severity level. Evidence of differentiation between fire severities was observed with some Myotis species having higher levels of activity in stands of high-severity burn. Larger-bodied bats, typically adapted to more open habitat, showed no response to fire. We found differential use of riparian and upland habitats among the phonic groups, yet no interaction of habitat type by fire severity was found. Extent of high-severity fire damage in the landscape had no effect on activity of bats in unburned sites suggesting no landscape effect of fire on foraging site selection and emphasizing stand-scale conditions driving bat activity. Results from this fire in mixed-conifer forests of California suggest that bats are resilient to landscape-scale fire and that some species are preferentially selecting burned areas for foraging, perhaps facilitated by reduced clutter and increased post-fire availability of prey and roosts. © 2013 Buchalski et al. Source


Meynard C.N.,Montpellier SupAgro | Soto-Gamboa M.,Austral University of Chile | Heady III P.A.,Central Coast Bat Research Group | Frick W.F.,University of California at Santa Cruz
Biodiversity and Conservation | Year: 2014

Forestry plantations represent about 4 % of the global land cover and demand for wood is steadily increasing worldwide. Impacts of forest plantations on biodiversity are controversial; forest plantations could positively influence biodiversity by producing a buffer zone between native forests and agriculture, while replacement of native forests with plantations could reduce biodiversity. Chile is one of the main producers of wood worldwide, and production is largely based on intensively managed monocultures of exotic tree species. Only a few studies have looked at the effects of forestry plantations on biodiversity in Chile, mainly focusing on pine plantations. The aim of this study was to characterize habitat use and richness of bats between native forests, eucalyptus plantations and grasslands in a biodiversity hotspot in southern Chile to determine how land use affects an important mammalian taxa. We found no difference in use or richness of bats in eucalyptus plantations versus native forests. Regional context within the larger Valdivian watershed (Andes, central valley, coastal range) had a stronger influence on bat activity and richness than land use type (native forest, plantation, grassland), with the Andean region being the most diverse and where most bat activity is concentrated. Our results suggest that the composition and structure of the surrounding landscape mosaic may be fundamental to determine the impacts of forestry and human land use on biodiversity. © 2014 Springer Science+Business Media Dordrecht. Source


Frick W.F.,University of California at Santa Cruz | Price R.D.,University of California at Santa Cruz | Heady P.A.,Central Coast Bat Research Group | Kay K.M.,University of California at Santa Cruz
American Naturalist | Year: 2013

Plant-pollinator interactions are great model systems to investigate mutualistic relationships. We compared pollinator effectiveness between facultative and obligate nectar-feeding bats to determine how foraging specialization influences mutualistic interactions in a bat-adapted cactus. We predicted that a specialized nectarivorous bat would deliver more pollen than an opportunistic nectar-feeding bat because of specialized adaptations to nectar feeding that indicate close association with their food plants. Counter to our predictions, the opportunistic Antrozous pallidus delivered significantly more pollen grains per visit than the specialized Leptonycteris yerbabuenae. Higher pollinator effectiveness, based on visitation rates and pollen deposition levels, varied between species by site, and although A. pallidus visits flowers much less frequently than L. yerbabuenae over all sites, it is likely an effective and reliable pollinator of Pachycereus pringlei in Baja, Mexico. Our results suggest that morphological adaptations and dietary specialization on nectar do not necessarily confer advantages for pollination over less specialized plant visitors and highlight the reciprocally exploitative nature of mutualisms. © 2012 by The University of Chicago. Source


Frick W.F.,University of California at Santa Cruz | Shipley J.R.,Cornell University | Kelly J.F.,University of Oklahoma | Heady III P.A.,Central Coast Bat Research Group | Kay K.M.,University of California at Santa Cruz
Oecologia | Year: 2014

Many animals have seasonally plastic diets to take advantage of seasonally abundant plant resources, such as fruit or nectar. Switches from insectivorous diets that are protein rich to fruits or nectar that are carbohydrate rich present physiological challenges, but are routinely done by insectivorous songbirds during migration. In contrast, insectivorous bat species are not known to switch diets to consume fruit or nectar. Here, we use carbon stable isotope ratios to establish the first known case of a temperate bat species consuming substantial quantities of nectar during spring. We show that pallid bats (Antrozous pallidus) switch from a diet indistinguishable from that of sympatric insectivorous bat species in winter (when no cactus nectar is present) to a diet intermediate between those of insectivorous bats and nectarivorous bats during the spring bloom of a bat-adapted cactus species. Combined with previous results that established that pallid bats are effective pollinators of the cardon cactus (Pachycereus pringlei), our results suggest that the interaction between pallid bats and cardon cacti represents the first-known plant-pollinator mutualism between a plant and a temperate bat. Diet plasticity in pallid bats raises questions about the degree of physiological adaptations of insectivorous bats for incorporation of carbohydrate-rich foods, such as nectar or fruit, into the diet. © 2013 Springer-Verlag Berlin Heidelberg. Source

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