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Mercury is a toxic element acquired by animals through feeding which can accumulate within food chains through biomagnification. This possesses particular risks to higher trophic levels and may unduly impact marine foraging species or individuals. The fish-eating bat (Myotis vivesi Menegaux, 1901) inhabits islands in the Gulf of California and can act as a predator in the marine environment. A predominantly marine diet and a high trophic position increase the risk of mercury exposure owing to increased bioaccumulation. Using molecular techniques to reconstruct diet, we show that M. vivesi regularly feeds on small fishes and crustaceans, particularly on the Californian anchovy (Engraulis mordax Girard, 1854) and a krill species (Nyctiphanes simplex Hansen, 1911). Additionally, we identify significant interannual variation in diet composition within this population, but measured levels of total mercury in faecal samples were not related to dietary diversity or trophic level. Key words: biomagnification, DNA barcoding, diet analysis, mercury exposure, trophic transfer, Myotis vivesi, fish-eating bat. Le mercure est un element toxique acquis par les animaux par leur alimentation et il peut s'accumuler dans les reseaux trophiques par le biais de la biomagnification, ce qui pose differents risques pour les niveaux trophiques superieurs et pourrait avoir des impacts indus sur les especes ou individus s'alimentant en milieu marin. La chauve-souris piscivore (Myotis vivesi Menegaux, 1901) vit dans des îles du golfe de Californie et peut agir comme predateur dans le milieu marin. Un regime alimentaire a predominance marine et une position trophique elevee accroissent le risque d'exposition au mercure en raison d'une bioaccumulation accrue. En utilisant des techniques moleculaires permettant de reconstituer le regime alimentaire, nous demontrons que la chauve-souris piscivore se nourrit regulierement de petits poissons et crustaces, en particulier l'anchois du Pacifique (Engraulis mordax Girard, 1854) et une espece de krill (Nyctiphanes simplex Hansen, 1911). En outre, si nous relevons une variation interannuelle significative de la composition du regime alimentaire au sein de cette population, les teneurs de mercure total mesurees dans les echantillons fecaux ne sont pas reliees a la diversite de l'alimentation ni au niveau trophique. [Traduit par la Redaction] Mots-cles : biomagnification, codes-barres d'ADN, analyse du regime alimentaire, exposition au mercure, transfert trophique, Myotis vivesi, chauve-souris piscivore., Introduction The Gulf of California is an important area for biodiversity conservation in both the terrestrial and the marine environments (Enriquez-Andrade et al. 2005). High levels of species endemism, as [...]

Intraspecific variation in diet and (or) foraging behaviour is one way in which species are able to occupy wide geographical areas with variable environments. The little brown bat (Myotis lucifugus (Le Conte, 1831)), a primarily aerial insectivorous bat, consumes spiders in low temperatures at the start and end of summer in Northwest Territories, Canada, but it consumes spiders all summer, even during high aerial insect abundance, in Alaska, USA. There are no competitors of M. lucifugus in Alaska, but there are in Northwest Territories, suggesting that aerial insect abundance and competition from gleaning bats influences when M. lucifugus consumes spiders. In the Kananaskis area of the Rocky Mountains of Alberta, Canada, we investigated spider consumption by M. lucifugus and the long-eared myotis (Myotis evotis (H. Allen, 1864)), a species more adept at gleaning, to better understand when bats consume spiders. Fecal sample analysis indicated that M. evotis consumed spiders all season long, with greater consumption when the bats were caught near water. Myotis lucifugus did not consume spiders at all. This suggests that M. lucifugus opportunistically consumes spiders when encountered, but does not encounter them in Kananaskis where it forages primarily over open water, unlike in Northwest Territories where it forages in the interior of forests and may encounter spiders more frequently. Key words: Myotis lucifugus, little brown bat, Myotis evotis, long-eared myotis, Araneae, spiders, diet. Les variations intraspecifiques de l'alimentation et (ou) du comportement d'approvisionnement constituent un moyen par lequel les especes peuvent occuper de vastes regions geographiques aux milieux variables. Le vespertilion brun (Myotis lucifugus (Le Conte, 1831)), une chauve-souris insectivore principalement aerienne, consomme des araignees en peri-ode de basses temperatures au debut et a la finde l'ete dans les Territoires-du-Nord-Ouest (Canada), alors il consomme des araignees tout l'ete durant, meme en periode de grande abondance d'insectes aeriens qu'en Alaska (Etats-Unis). Le vesperti-lionbrunn'a pas de concurrent en Alaska, mais en a aux Territoires-du-Nord-Ouest, ce qui donne a penser que l'abondance d'insectes aeriens et la concurrence de chauves-souris glaneuses jouent un role dans la determination des periodes ou les vespertilions bruns consomment des araignees. Nous avons examine, dans la region de Kananaskis des montagnes Rocheuses de l'Alberta (Canada), la consommation d'araignees par les vespertilions bruns et par les vespertilions a longues oreilles (Myotis evotis (H. Allen, 1864)), uneespeceplus porteesur le glanage, afin de mieux comprendre quand les chauvessouris consomment des araignees. L'analyse d'echantillons fecaux indique que les vespertilions a longues oreilles consomment des araignees durant toute la saison, cette consommation etant plus grande quand les specimens sont captures pres de plans d'eau. Les vespertilions bruns ne consomment pas du tout d'araignees. Cela indiquerait que les vespertilions bruns consomment des araignees de maniere opportuniste quand ils en rencontrent, mais qu'ils n'en rencontrent pas a Kananaskis, ou ils s'alimentent principalement au-dessus de plans d'eau ouverts, contrairement aux Territoires-du-Nord-Ouest, ou ils s'alimentent a l'interieur de forets et peuvent rencontrer des araignees plus frequemment. [Traduit par la Redaction] Mots-cles : Myotis lucfugus,vespertilion brun, Myotis evotis, vespertilion a longues oreilles, Araneae, araignee, regime alimentaire., Introduction Intraspecific variation in diet or foraging behaviour among populations in different geographic locations can occur due to differences in external factors between locations, including abiotic factors such as temperature [...]

Guano was analyzed for seven bat species captured while foraging within and adjacent to sites in south-central Indiana both before and after the sites were used as no-harvest controls or experimentally manipulated with either even-aged (clear-cut and shelterwood cut) or uneven-aged (group and single tree selection) techniques as part of the Hardwood Ecosystem Experiment (HEE). Despite collecting samples for six years, sufficient samples for comparison were obtained for only three species: northern long-eared bat (Myotis septentrionalis), big brown bat (Eptesicus fuscus), and eastern red bat (Lasiurus borealis). None of these species experienced a significant change in diet associated with experimental harvest. This result is surprising because concurrent studies on the HEE have shown insect prey abundance changes as a response to harvest treatments. Our results reinforce previous conclusions that bats are selective opportunists that focus on particular groups of insects even when habitat manipulations change the abundance of those foods. Keywords: Bats, diet, forest management, Hardwood Ecosystem Experiment (HEE), INTRODUCTION Insectivorous bats feed on night-flying insects, including many pest species. Understanding how the diets of these species changes with changing forest conditions is important to understand how bats respond [...]

Temperate bat species are well-known predators of nocturnal insects; however, their role in forest nutrient cycling is unclear. We tested the 'nutrient hot spot' hypothesis, which suggests that colonial bats should create nutrient peaks in and around their roosts via guano deposits. We measured the mass and nitrogen content of guano deposited outside of roosts occupied by maternal colonies of 2 tree-roosting species, Myotis septentrionalis and M. sodalis. We assessed whether these measures were related to date, species, and bat abundance using least-squares regression. We then compared the expected amount of nitrogen deposited over a maternity season to the expected annual amount of nitrogen mineralized by a forest. Mass of guano deposited increased with bar abundance and corresponded to periods of parturition and lactation. Nitrogen mineralization near a large roost of bats can be 380% of that due to decay of leaf litter. Such nutrient peaks could influence patterns of forest vegetation by impacting growth of herbaceous plants and development of tree seedlings, and the magnitude of these effects should increase in nutrient-poor areas. DOI: 10.1644/08-MAMM-A-308R2.1. Key words: Chiroptera, guano, Myotis septentrionalis, Myotis sodalis, nitrogen, nutrient cycling [c] 2010 American Society of Mammalogists

Foraging plasticity that includes facultative nectarivory is extremely rare in temperate insectivorous bats. We investigated flower-visiting behavior of pallid bats (Antrozous pallidus, Vespertilionidae) to bat-adapted flowers of cardon cacti (Pachycereus pringlei) to determine whether pallid bats consume floral nectar or visit flowers to opportunistically glean insects attracted to flowers. In 2007 and 2008, we recorded flower-visiting behavior of bats using infrared videography on 143 cactus-nights across 14 sites in Baja California, Mexico. Pallid bats were regular visitors to cardon flowers and consumed floral nectar by plunging their faces into the corolla to lap pooled nectar. We recorded 1,198 flower visits by A. pallidus, which accounted for 10% of visits to flowers by all bats. Pallid bats visited flowers on 57% of cactus-night observations (n = 81/143) and 52% (n = 28/54) of captured bats had visible pollen loads. Flower-visiting activity by A. pallidus was concentrated early in the evening where nectarivorous Mexican lesser long-nosed bats (Leptonycteris yerbabuenae [= curasoae], Phyllostomidae) were present, but more evenly distributed throughout the night at sites without L. yerbabuenae, suggesting potential competitive exclusion among these nocturnal chiropteran pollinators. Key words: Antrozous pallidus, bat pollination, columnar cacti, foraging behavior, Leptonycteris yerbabuenae, nectarivory

We investigated food habits and relationships between food resource abundance and activity of bats. We identified prey remains in guano collected from 337 individuals in the Oregon Coast Range. Guano analyses indicated that 2 species, long-legged myotis (Myotis volans) and Townsend's big-eared bat (Corynorhinus townsendii), consumed predominantly Lepidoptera; 4 species, California myotis (M. californicus), little brown myotis (M. lucifugus), Yuma myotis (M. yumanensis), and silver-haired bat (Lasionycteris noctivagans), consumed predominantly smaller insects likely of aquatic origin (Diptera and Trichoptera); and the remaining 4 species, long-eared myotis (M. evotis), fringed myotis (M. thysanodes), big brown bat (Eptesicus fuscus), and hoary bat (Lasiurus cinereus), consumed predominantly larger invertebrates of terrestrial origin (Lepidoptera, Coleoptera, Hemiptera, and Araneae). We hypothesized that bat activity in riparian areas would be correlated with abundance of preferred insect prey and used an information-theoretic approach to determine whether variability in bat activity was more strongly associated with captures of all insects, of taxa most frequently occurring in the diet, or of particular size classes of insects. We found strong associations between activity of small Myotis species and number of captures of small insects, but activities of larger Myotis species and of non-Myotis species were not associated with numbers of insects of any category. Key words: activity, bats, diet, insects, prey, resource selection, riparian, western Oregon

The fragmentation of forests by the expansion of agriculture is recognized as an important factor influencing worldwide declines of forest-dependent species. Species that are forest dependent may be especially vulnerable to fragmentation because they have specialized resource requirements and may exhibit lower mobility in an agricultural matrix. We investigated movement patterns and resource selection of forest-dependent northern long-eared myotis (Myotis septentrionalis) in a forest-agricultural landscape on Prince Edward Island, Canada. Radiotelemetry was used to locate day-roosts and to estimate locations of female bats during nightly foraging bouts. Day-roost locations and foraging areas were mapped using a geographic information system to generally characterize the forest cover of foraging and roosting areas. Vegetative structure and insect prey availability were measured in the field and compared between foraging and roosting areas to describe resource selection at these sites. Movements of female northern long-eared myotis were constrained to forest features and foraging areas were concentrated along forest-covered creeks with bats roosting predominantly in deciduous trees within the same forest fragment, although bats at 1 site seemed to exclusively use a barn during late pregnancy and lactation. Differences in prey availability did not explain the spatial segregation of roosting and foraging areas. Relative to roost areas foraging sites were more likely to be close to forested creeks and densely forested areas, whereas roost sites were characterized by the availability of potentially suitable roosts. This study demonstrates the importance of investigating movements and resource selection of individuals in fragmented landscapes because a specialization on forest resources can highly restrict the vagility of forest-dependent species to a local environment. Key words: Chiroptera, forest fragmentation, forest structure, Prince Edward Island, radiotelemetry, roost trees

We studied the morphology and diet of Musonycteris harrisoni, an endangered nectar-feeding bat endemic to western Mexico, and explored potential reasons for the cranial specialization of this extraordinarily long-snouted bat. We achieved 28 captures in the wet season and 30 in the dry season, which represents the largest data set in existence for this rare species. We took morphological data and collected pollen from the bats' pelage. Diet analysis revealed the genera Cleome, Pseudobombax, Crataeva, Agave, Helicteres, and the columnar cactus Pachycereus pecten-aboriginum as main food plants. We found no indication for a tight relationship between M. harrisoni and long-tubed flowers that would obligatorily require a long rostrum for exploitation, with the possible exception of the columnar cactus. However, because cacti are common food plants for many less-specialized nectar-feeding bats, the extraordinarily long rostrum might permit M. harrisoni to use the same abundant plant species as larger species while maintaining a smaller body size, therefore having lower absolute energy requirements. This in turn could facilitate a resident lifestyle in a habitat with annual resource bottlenecks. Males have significantly longer snouts (approximately 9%) than females, suggesting that rostrum length also might be influenced by intraspecific interactions or restrictions. Our favored explanation is that the rostrum length of females may be limited by stability issues, because calcium mobilization during pregnancy and lactation can considerably weaken bone structure. Key words: Cactaceae, Colima, conservation, dry forest, endangered bats, evolution, pollination, sexual dimorphism, tongue length

Insectivorous bats require different resources for diurnal roosting and nocturnal feeding, and sound conservation planning requires knowledge of both. However, ranging behavior and habitat use by foraging bats are poorly known, especially within urban ecosystems. We studied foraging flight behavior and use of an urban landscape by 14 white-striped free-tailed bats (Tadarida australis) in metropolitan Brisbane, Australia. Each evening, the bats emerged from day-roosts in tree-hollows and commuted rapidly to a feeding area (median travel speed 42.9 km/h, based on net distances moved during 10-20 min). Within 30 min from emergence their travel speed was greatly reduced (median 6.7 km/h) to a level that remained similar throughout subsequent hours while they foraged. Day-roosts were widely dispersed across the urban landscape, but foraging bats mostly restricted their movements to a localized area of a few kilometers diameter. This area was closer to a communal roost, visited periodically by all bats, than to their day-roosts (median distance from foraging bats to the communal roost 2. 5 km; to their day-roosts 6.2 km). The bats showed a significant preference for foraging above floodplain habitat, and did not prefer to feed above remnant forest. T. australis appears tolerant of deforestation and capable of persisting in urban landscapes, provided that roost trees are protected. However, it remains unknown whether a sustained availability of aerial prey depends on floodplains remaining undeveloped. Key words: conservation, foraging behavior, habitat selection, molossid, radiotracking, Tadarida australis, travel speed, urban land use

A study was conducted in the Oregon Coast Range to determine the interdependence of the habitat of bats and riparian proximity. Results revealed that bats foraged closer to riparian areas and manipulation of vegetation in riparian areas should lay emphasis on maintaining habitat conducive to survival of bats.

In the Neotropics, bat-pollinated plants secrete relatively dilute nectars dominated by hexoses (glucose and fructose) with only small amounts of sucrose. We investigated the concentration and sugar composition preferences of Saussure's long-nosed bat (Leptonycteris curasoae) and the long-tongued bat (Glossophaga soricina) to test the hypothesis that bats prefer the predominant characteristics (sugar composition and concentration) found in their natural diets. We offered bats pairs of test diets in large outdoor enclosures that allowed free flying. We used artificial nectars that simulated compositions and concentrations found in flowers visited by these 2 species at the study site. Contrary to our predictions, bats showed no preference between sugar types when test solutions had the same concentration. However, L. curasoae preferred concentrated over dilute solutions independent of sugar type. Only 1 preference for concentrated over dilute solutions was recorded for G. soricina. Both species of bat appeared to perceive sugar types as energetically equivalent in most trials. Our study rejects the hypothesis that nectar-feeding neotropical bats act as a selective pressure on nectar composition in chiropterophilous plants. Other possible explanations for the predominance of hexose in chiropterophilous flowers need to be evaluated. Key words: bats, Chiroptera, chiropterophilous flowers, concentration preferences, dry forest, energetic equivalence, Mexico, pollination ecology, sugar preferences

Limited information exists on the foraging ecology of the long-legged myotis (Myotis volans), especially with regard to use of available foraging habitats in large, relatively contiguous forested landscapes. During the summers of 2004 and 2005, we radiotagged adult long-legged myotis (n = 70) in north-central Idaho to estimate the size of home ranges and to evaluate use of available foraging habitats. Size of home range and core areas was measured for individuals with [greater than or equal to] 31 locations (n = 30) using the adaptive kernel method, and selection among available foraging habitats was evaluated using Euclidean distance analysis. Home-range estimates did not differ among males, pregnant females, and lactating females (P = 0.52). Core-area estimates also did not differ among males, pregnant females, and lactating females (P = 0.62). Second-order habitat analysis, based on vegetation, showed that home ranges of males (P = 0.01), pregnant females (P = 0.001), and lactating females (P = 0.001) all were closest to stands of medium-diameter trees, that is, trees predominantly 12.7-38.0 cm diameter at breast height (dbh), that also contained larger snags typically used as roosts ([bar.X] = 54.0 cm dbh; n = 100). Second-order habitat analysis, based on slope position, showed that home ranges of males (P = 0.0001), pregnant females (P = 0.001), and lactating females (P = 0.001) were closest to mid-slope positions. Third-order habitat analysis, based on either vegetation or slope position, did not differ from random use for males, pregnant females, and lactating females. More lepidopterans were captured in black-light traps at mid-slope positions than either upper or lower slope positions. Fecal pellets (n = 171) from 62 long-legged myotis revealed a diet primarily composed of Lepidoptera (49.2% volume, 100% frequency) and Coleoptera (31.1% volume, 100% frequency). Examination of our data demonstrates the importance of forest stand structure, topographic position, and abundance of moths in foraging habitat for long-legged myotis. Key words: diet, foraging areas, foraging habitat, habitat selection, home range, Myotis volans, prey selection

Published information about the diet of eastern small-footed bats (Myotis leibii) does not exist. Feces of 39 M. leibii captured from May through Sep. in southern New Hampshire contained eight orders of insects, spiders (Araneae), unidentified arthropods and vegetation. Moths (Lepidoptera), true flies (Diptera) and beetles (Coleoptera) composed most of the diet. Diet of adult males contained significantly fewer beetles than that of juveniles, but diet was similar between other demographic groups and across seasons. Presence of spiders and crickets (Gryllidae) in the diet suggested M. leibii captured some prey via gleaning., INTRODUCTION Myotis leibii is considered one of the rarest species of bats in North America and is a species of concern in most states and provinces where it occurs (Barbour [...]

We determined the foods habits of 5 species of microchiropteran bats (Hipposideros commersoni, Triaenops rufus, Triaenops furculus, Myotis goudoti, and Miniopterus manavi) in the austral winter and summer in a dry deciduous forest in western Madagascar using fecal analysis. We also assessed food availability and bat activity in 4 forest microhabitats. Despite overlap in dietary composition, H. commersoni consumed mainly Coleoptera; M. goudoti consumed mainly Hymenoptera, Neuroptera, and Araneae; M. manavi consumed mainly Hemiptera; and T. rufus and T. furculus consumed mainly Lepidoptera. Diptera were the most abundant insects in traps but were rarely encountered in feces. H. commersoni was not netted during the austral winter, but the other 4 species changed their diet according to seasonal availability, with lepidopterans the most important diet items in winter and coleopterans in summer. We consistently trapped a higher abundance of potential bat prey at the forest edge, whereas the forest interior was low in both food availability and bat activity. The 5 microchiropterans studied partitioned the available food mainly through dietary specialization, although spatial and temporal partitioning also may play a role. More research is needed to assess levels of dependency on forest by these bats, and to investigate the seasonal ecology of H. commersoni and interspecific competition between T. rufus and T. furculus. Key words: bats, competition, food habits, Hipposideros commersoni, Madagascar, Miniopterus manavi, Myotis goudoti, Triaenops furculus, Triaenops rufus

By any standard, bats are a successful group of mammals and the evolution of flight and echolocation were certainly key innovations behind their success. That is only part of the story, however. Bats have diversified into trophic niches that range from insectivory to feeding on blood, fruit, or nectar. While flight places fundamental constraints on the shape of the postcranial skeleton, skull shape in bats is remarkably diverse. Morphological studies of individual families and sympatric assemblages demonstrate that variation in skull shape is clearly associated with trophic specialization. Field experiments demonstrate that species-specific biting behaviors during feeding are common and analyses indicate that the evolution of cranial morphology and feeding behavior are correlated. Modeling experiments further suggest that feeding (loading) behaviors and skull shape are functionally linked. If the skulls of bats are under selective pressure for minimal mass because of the energetic demands of flight, then they may be more 'optimized' to meet mechanical demands than are the skulls of other mammals. This would make bats a unique model system for studying the evolution of diversity in skull shape and its functional implications for the evolution of feeding strategies in mammals.

We evaluated composition and seasonal variation in the diet of Rickett's big-footed myotis (Myotis ricketti) by examining 342 fecal samples collected every 2 weeks when the bats were active in Fangshan District of Beijing, North China, from 2002 to 2003. The diet consisted of 3 kinds of fish (Zacco platypus, Carassius auratus, and Phoxinus lagowskii) and at least 7 orders of insects (Coleoptera, Lepidoptera, Homoptera, Ephemeroptera, Hemiptera, Diptera, and Hymenoptera). Fragments of fish accounted for 67.1% and fragments of insects for 28% (by volume) of the diet; Z. platypus was the dominant food (60.1%), followed by Coleoptera (13.1%). Significant differences existed between the proportion of fish and insects in the diet; however, no seasonal variation in the diet was found over the course of the investigation. This suggests that at this study site in Beijing, M. ricketti was highly specialized in foraging on only 1 species of fish and relied less on insects as alternative food sources, despite their seasonally high abundance. Key words: Beijing, China, diet, fecal analysis, Rickett's big-footed bat

We examined the diet of 2 island-dwelling phyllostomids, the brown flower bat (Erophylla sezekorni) and the Greater Antillean long-tongued bat (Monophyllus redmani), by analyzing fecal contents and pollen swabs from >100 individuals of each species. Although both bats are putative nectar-feeders, their feeding niches were differentiated. A greater proportion of M. redmani (91%) consumed nectar compared with E. sezekorni (50%), but the reverse was true for fruits (22% versus 85%, respectively); about 75% of both species included insects in their diets. However, insect consumption in E. sezekorni was dominated by coleopterans, whereas in M. redmani, diet was more diverse and included soft-bodied prey, such as lepidopterans and dipterans. Both species consumed fruits of Panama berry (Mutingia calabura) and elder (Piper aduncum), but E. sezekorni also included turkey berry (Solanum torvum). When consuming nectar, E. sezekorni often led at flowers of guava (Psidium guajava), whereas M. redmani visited flowers of guava, woman's tongue (Albizia lebbek), myrtle (Eugenia), and wild tamarind (Leucaena leucocephala). Interspecific differences in diet are consistent with published differences in craniodental and wing (flight) characteristics. The more diverse diet of M. redmani and its lesser reliance on fruit may allow it to survive stochastic events, such as hurricanes, and recover more quickly than populations of E. sezekorni. Key words: bats, diet, Erophylla sezekorni, food, frugivory, fruit, Monophyllus redmani, nectarivory, pollen, Puerto Rico

Food habits of the endangered gray myotis (Myotis grisescens) were ascertained from 10,736 fecal pellets collected from 1,225 bats of known sex, age, reproductive condition, and capture locations, including 5 maternity caves and 2 dispersal caves in Missouri. Diets were compared to availability of insects in 80 light-trap samples collected concomitantly with fecal samples. Proportional availability of insects varied among locations, over the season, between seasons, and between early-evening and late-night samples. Similarly, the diet varied among locations, over time, between early and late samples, and among sample groups by sex, age, and reproductive condition. Trichopterans, coleopterans, and lepidopterans were important in the diet and in light-trap samples, but there was poor correlation between corresponding diet and light-trap samples. Plecopterans, ephemeropterans, and dipterans were occasionally common in light-trap and dietary samples, although again there was poor correlation between corresponding diet and light-trap samples. Gray myotis forage individually over long distances along streams and wooded riparian habitats. Although this habitat produces a characteristic assemblage of insect prey, proportional availability varies temporally and spatially. Thus, although specific diet samples do not match corresponding insect samples, on a broader scale, diets and insect availability do correspond. On a microscale, the gray myotis exhibited some characteristics of an opportunistic Forager, feeding on readily available prey, but on a macroscale was selective, feeding in aquatic-based habitats where specific types of insect prey were abundant. Juveniles foraged more in woodlands and ate more coleopterans, which may provide a greater energy reward per unit of capture effort, than did adults. Conservation efforts should include both aquatic and wooded riparian habitats. Key words: food habits, foraging ecology, gray myotis, insect prey, maternity caves, Myotis grisescens

We investigated the diets of insectivorous bats (Chiroptera: Vespertilionidae) in forests with high densities of western spruce budworm (Choristoneura occidentalis, Lepidoptera: Tortricidae), in southern interior British Columbia, Canada. Caterpillars as potential prey were more common and widespread than previously reported. Caterpillar consumption by bats was more frequent where C. occidentalis larvae were more abundant, suggesting that the caterpillars being eaten were C. occidentalis. The frequency of caterpillar consumption was similar for Myotis evotis, which gleans prey from vegetation, and for other bat species that forage primarily by aerial-hawking. We suggest that caterpillars hanging by silk threads were captured by bats that foraged aerially.

This study documents the diet of Mexican free-tailed bats (Tadarida brasiliensis mexicana) at Carlsbad Cavern, Carlsbad Caverns National Park, Eddy County, New Mexico, and provides information on seasonal variation in food habits of this species throughout its summer residence. Diet was determined from 1,303 fecal samples. Eleven orders and 38 families of insects, unidentified insects, 2 orders of Arachnida (Araneae and Acari), bat hair, and mist net were consumed, with Lepidoptera (moths) and Coleoptera (beetles) occurring at greatest percentage volumes and percentage frequencies in the diet. Diet varied significantly throughout the season. Twenty-two food categories exhibited statistically significant variation among sampling sessions. Amounts of Coleoptera, Lepidoptera, Formicidae, Psyllidae, Hymenoptera, and Diptera consumed showed the greatest differences among sampling sessions. Key words: Chiroptera, diet, fecal analysis, food habits, seasonal variation, Tadarida brasiliensis

We examined food habits of Brazilian free-tailed bats (Tadarida brasiliensis) at 3 colonies in central Texas over 3 summers. Fecal samples collected from 1,550 bats contained remains of 12 orders and 35 families of insects, documenting the most diverse diet ever reported in insect-eating bats. Daily and seasonal patterns of insect consumption were similar at the 3 sites and closely correlated to patterns of emergence, migration, and availability of adult populations of corn earworms Helicoverpa zea and fall armyworms Spodoptera frugiperda, both species of noctuid moths and major crop pests. The percentage of feces volume comprised by moth remains increased from 14.8% [+ or -] 2.1 SE (range: 6.3-43.7%) to 43.0% [+ or -] 7.1 (range: 1.7-73.5%) in samples collected at midnight versus dawn on days when large influxes of migratory moths arrived in Texas in early morning, following their massive emergence from northern Mexico. Daily patterns diminished later in the season, after moth populations became established in local crops and were available in large numbers throughout night. Moth consumption decreased in both evening and dawn feeding periods when crops senesced and moth populations declined. These and other data suggest that crop pests comprise a substantial portion of the bats' diet and that bats provide valuable natural pest control services. Key words: bats, crop pests, diet, moths, Tadarida brasiliensis

We examined food habits of Tylonycteris pachypus and T. robustula by fecal analysis in 2 counties of Guangxi, South China. The diet of T. robustula included 7 orders of insects: Hymenoptera (62.3% by volume), Diptera (29.6%), Coleoptera (6.0%), Hemiptera (1.5%), and traces of Orthoptera, Trichoptera, and Ephemeroptera. The diet of T. pachypus included all the main orders consumed by T. robustula (53.4%, 29.0%, 13.4%, 2.1%, respectively) and 3 other orders: Homoptera, Blattodea, and Embioptera. No differences were found in diets of males and females of either species. The diet of T. pachypus showed clear seasonal variation from spring to autumn and differences in diet between the different geographical areas studied. There were no differences in the 4 dominant insect orders consumed by both species in Longzhou County, but insects consumed by T. pachypus were characteristically smaller than those eaten by T. robustula, and food-niche breadth (based on prey size) also was smaller than that of T. robustula. Key words: diet, flat-headed bats, geographic variation, resource partitioning, seasonal variation, sex variation, South China, Tylonycteris pachypus, Tylonycteris robustula

We evaluated partitioning of food resources among syntopic eastern red (Lasiurus borealis), Seminole (L. seminolus) and evening (Nycticeius humeralis) bats at the Savannah River Site, South Carolina, from June through August of 1996 and 1997. We compared diets to indices of relative prey availability, which were based on samples of the insect communities in bat foraging habitats and the amounts of time the bats foraged in each habitat. The relative proportions of insect orders consumed differed among the species. We recorded only minor differences between insect consumption and indices of prey availability, as assessed by insect light traps placed within foraging habitats. Our data suggest that Eastern red bats and evening bats altered their prey selection late in the summer.

The feeding ecology of most neotropical bat species is still poorly known, indicating that many complex ecological relationships may be obscured. During a study of bats and their potential role as seed dispersers at the Botanical Garden of Rio de Janeiro, southeastern Brazil, we obtained data on 2 species, Chiroderma doriae and C. villosum, that act as seed predators rather than as seed dispersers. Fecal sample analyses and captive-feeding experiments confirmed this previously undocumented feeding strategy in bats. Both species use a specialized strategy of fig-seed predation, ingesting the rich nutrient content of seeds and discarding most of the coat fragments as compact oral pellets. Evidence from the more abundant C. doriae showed that seeds were consumed in both drier and wetter seasons and by individuals of both sexes, all age classes, and all reproductive stages. Use of seeds, in addition to fruit pulp, probably represents an improvement in the acquisition of nutrients available in figs, showing that the degree of feeding specialization of Chiroderma on this resource may be higher than previous data have shown. Key words: Chiroderma doriae, Chiroderrna villosum, Ficus, predation, feeding behavior, southeastern Brazil

We used stable carbon and nitrogen isotope analyses to test the hypothesis that nectar-feeding bats Leptonycteris curasoae and Glossophaga longirostris depend on cacti and agaves as food sources in Venezuelan arid zones and to compare their trophic positions. We measured the isotopic compositions of muscle tissue in the 2 species during 1 year at 3 arid locations. Overall carbon isotopic composition ([[??].sup.13]C) of L. curasoae (-11.76 [per thousand]) and G. longirostris (-13.28 [per thousand]) resembled values characteristic of columnar cacti and agaves (-12.47 [per thousand]), which have in common the crassulacean acid metabolism (CAM) photosynthetic pathway. L. curasoae appears to be more dependent on cacti and agaves (98% CAM in the diet) than G. longirostris (85% CAM in the diet). CAM dependence, as we designate dependence on cacti and agaves, was evidenced across sites. Level of CAM dependence slightly varied over the year only in G. longirostris. We concluded that the 2 species of bats mainly rely on CAM plants in Venezuelan arid zones. Overall nitrogen isotopic composition ([[??].sup.15]N) did not differ between L. curasoae (15.87 [per thousand]) and G. longirostris (15.37 [per thousand]). Although our results suggest that the 2 bats occupy the same trophic position, no conclusive evidence supported this observation. The strong interdependence between these bats and their host CAM plants in northern South America suggests that a disturbance affecting 1 component of the interaction would have a strong effect on the other. Key words: arid zones, CAM plants, carbon, Glossophaga longirostris, Leptonycteris curasoae, nectar-feeding bats, nitrogen, stable isotopes, Venezuela

I evaluated the diet of the golden-tipped bat, Kerivoula papuensis (Vespertilionidae), at 3 sites in eastern Australia. Spiders (Araneida) dominated (>95%) feces collected from captured individuals or from beneath roosts at all sites. Araneida also occurred in 63% of 27 captured individuals; fragments of prey were located between teeth or adhering to facial fur at 1 site. A small percentage of fragments were identified to family, and all belonged to the web builders, Araneidae or Tetragnathidae. Marked K. papuensis individuals were observed only in cluttered rain forest, with all individuals flying among vegetation at an average height of about 3.4 rn (range, 1 - 10 m). No direct gleaning attempts were observed, although hovering may have represented a strategy to capture Araneida suspended in webs. These results indicate that K. papuensis is a spider specialist, although smaller quantities of other types of prey were taken, including Coleoptera and Lepidoptera, demonstrating dietary flexibility.

I tested the hypothesis that New World nectarivorous and frugivorous bats prefer sugars that predominate in fruits and nectars that they ingest. Accordingly, preference for the hexoses glucose and fructose over sucrose was predicted for two frugivorous (Artibeus jamaicensis and Sturnira lilium) and one nectarivorous (Anoura geoffroyi) species. I also determined digestive efficiency of A. geoffroyi and A. jamaicensis for solutions of sucrose, glucose, and fructose. Bats consistently preferred sucrose over equicaloric solutions of fructose and glucose. Sugars were assimilated with the same efficiency by both species. Results were not consistent with previous studies on other groups of pollinators and seed dispersers. Key words: Phyllostomidae, bats, digestion, coevolution, diet, frugivory, Mexico, nectar-ivory, sugar

The sounds made by certain combinations of plastic or metal rings used to mark bats for identification can be heard by tympanate moths. These sounds may then prompt escape behaviour. The lower frequency of ring sounds could make them more apparent than echolocation calls to most tympanate insects with best frequencies of between 20 kHz and 50 kHz. Further research could consider whether double-ringed bats catch fewer tympanate insects than single-ringed bats.

We examined dietary characteristics of juvenile, yearling, and adult big brown bats (Eptesicus fuscus) at two maternity colonies in southeastern Alberta, Canada. The diet of E. fuscus included nine orders of insects in 1994 and 1995: Coleoptera, Hemiptera, Lepidoptera, Diptera, Trichoptera, Neuroptera, Hymenoptera, Ephemeroptera, and Homoptera. The diet of adult E. fuscus was dominated by Coleoptera. Juvenile E. fuscus consumed significantly fewer Coleoptera and more Hemiptera than did adults in 1994, but diets did not differ between age classes in 1995. Juveniles included a greater range of and softer items in their diets than did adults. Yearlings (bats that have survived their first winter) and adults did not differ significantly in diet. Key words: Eptesicus fuscus, big brown bat, diet, foraging, ontogeny, prey selection

During spring and summer 1991, a total of 1,476 fresh fecal pellets of gray bats, Myotis grisescens, was collected at Blowing Wind Cave, Jackson Co., Alabama. Fourteen orders of Insecta, unidentified Insecta, an unknown organism (possibly Insecta), two orders of Arachnida, and hair from gray bats were recovered; in decreasing order, the most common taxa were Lepidoptera, Diptera, and Coleoptera. Food categories exhibited significant variation among sampling sessions, nights within sampling sessions, and hours within sampling sessions. When quantity of each food category in fecal pellets was compared with quantity of potential prey available for consumption, there was no statistically significant correlation. There was significant variation in diet over time, but bats did not select prey in proportion to availability. Key words: Myotis grisescens, gray bat, endangered species, diet, food habits, feces, behavior, Alabama

It is generally assumed that during winter insectivorous bats in cold climates hibernate, and thus do not feed, whereas bats in warmer areas remain active and do feed. However, bats often fly about in winter, even in higher latitudes, and it has been assumed that they were feeding, based on bits of chitin in intestines and on the occurrence of feeding buzzes. However, little brown (Myotis lucifugus) and northern myotis (M. septentrionalis) and big brown bats (Eptesicus fuscus) flying in winter in central Indiana do not feed. We examined digestive tracts of red bats (Lasiurus borealis) that were collected in winter in The Great Dismal Swamp, about 250 miles S of Indiana in coastal northeastern North Carolina and southeastern Virginia. In contrast to the bats in Indiana, these bats fed throughout the winter. Moths and flies constituted over 90% of the volume of food in 24 individuals., INTRODUCTION It is generally assumed that during winter insectivorous bats that remain in cold climates hibernate, and thus do not feed, whereas bats in warmer areas remain active and feed, [...]

In this paper I quantify and compare patterns of use of habitat and diet of adult and juvenile little brown bats (Myotis lucifugus). Individuals were captured in mist nets as they foraged. Clutter indices (CIs) ranging from 0 (least cluttered) to 5 (most cluttered) were used to categorize feeding microhabitats based on density of vegetation. A total of 378 M. lucifugus was banded over a 2-year period and dietary analysis was performed on fecal samples from 90 individuals. Foraging patterns of juveniles and adults differed significantly, and patterns of adult were density dependent. When population density was high, adults moved from foraging primarily in open areas close to the ground (CI1) to semiclutter and heavy clutter microhabitats (CI3, CI4, and CI5). Adults shifted foraging areas in mid-July when juveniles developed volancy. When density of the population was low (the result of a population crash at the site), adults foraged in CI1 throughout summer and did not shift habitats. Juveniles foraged predominantly in the least-cluttered microhabitat (CI0) in both years independent of density of population. Key words: Myotis lucifugus, foraging patterns, resource partitioning

Predation upon insects by the bat Hipposideros caffer was studied at Skukuza in the Kruger National Park of South Africa. These bats, whose echolocation calls are inaudible to moths, fed overwhelmingly upon tympanate Lepidoptera, although insects of other orders frequently dominated the local light-responsive, flying, nocturnal insect community. The relative numbers of noctuid, pyralid, and arctiid moths taken by the bats were proportional to the representation of these families in the general population of moths, but they took disproportionately fewer moths of the family Geometridae. The bats also ate significantly fewer arctiid moths of those species capable of clicking than of those species that could not. Because the arctiids could not hear approaching H. caffer, these moths did not click before contact with an attacking bat, and their clicks could not protect them by interfering with echolocation by the predators. These results are consistent with the startle and acoustic-aposematism hypotheses for the bat-protective function of arctiid clicks. Key words: Hipposideros caffer, acoustic defenses, predation preferences, echolocation

Predation risk from bats which hunt airborne prey apply to all nocturnally flying insects that show sexual dimorphism during flight. The study on two species of insectivorous bats, Lasiurus cinereus and L. borealis shows that they consumed remarkably more male than female moths in the wild. This is due to sexual dimorphism related to sexual differences in mate acquiring technique. The peak of male and bat activity coincide in the middle of the night, but female activity peaked earlier in the night when bat activity is comparatively low.

Levels of nitrogen, sodium, potassium, magnesium, calcium, and iron were determined for suckling young of known-age, lactating Myotis velifer and Tadarida brasiliensis, and milk from T. brasiliensis nursing known-age young. From birth to weaning, relationships of both nutrient concentrations and nutrient accretion to age are similar for both species but differ for each nutrient and generally reach adult concentration by weaning. While total mass of body sodium and potassium reach adult levels in both species well before weaning, levels of other elements do not. Although comparable data are limited, element concentrations in suckling bats are similar to those for other suckling small mammals and nestling birds. Growth requirements for measured nutrients in these bats are lower than published values for rodents. Most mineral nutrients that were measured in milk for T. brasiliensis varied with stage of lactation and were comparable in concentration with milk of other mammals. Using daily accretion of nutrients and their concentrations in milk, we calculated the minimal mass of milk needed to meet growth requirements in suckling T. brasiliensis. Among measured nutrients, calcium is the limiting nutritional factor that determines mass of milk needed by suckling young during postnatal growth. Key words: bat, Chiroptera, nitrogen accretion, mineral accretion, nutrition, milk composition, postnatal growth, Myotis velifer, Tadarida brasiliensis

Concentrations of nitrogen and minerals in individual fecal pellets of Noctilio leporinus directly reflect composition of the fish, crustaceans, beetles, or moths originally consumed. Among Neotropical bats that feed primarily on plant parts (fruits, nectar, pollen, and flowers), animal parts (insects and vertebrates), or both, differences in measured concentrations of nutrients are present in feces. Nitrogen levels are markedly higher and sodium levels are marginally higher in feces of carnivores and omnivores than in frugivores. Calcium levels are higher and potassium levels are lower in feces of bats that primarily consume insects. Total iron levels in feces of frugivorous species are marginally lower than in carnivores or omnivores. Magnesium concentrations seem unrelated to feeding habits. Intake of nitrogen, potassium, and magnesium appears to be adequate for bats of all feeding habits. Periodic deficiencies for calcium exist for insectivorous species and for sodium, and possibly iron, in some frugivorous species.

The diets of hoary bats (Lasiurus cinereus) within the first 2 weeks post-fledging were studied by means of fecal analysis. Results were compared to the diet of adult hoary bats within the same area. Juvenile bats consumed significantly fewer Odonata than did adults. Chironomidae (Diptera) were the major contributor to the diet of juveniles during the 1st week of flight, but were a negligible component in the diet of older juveniles or adults. Due to a lack of experience, juveniles likely have poor handling skills of larger insects. However, lower wing loading and greater maneuverability may make small prey more available to juveniles.

Foraging ecology and summer habitat requirements remain unknown for the Virginia big-eared bat (Plecotus townsendii virginianus), an endangered subspecies of Townsend's big-eared bat. Thus, w examined use of cliff habitat by this bat in Daniel Boone National Forest (DBNF), Kentucky, in 1990- and measured 21 habitat variables in 241 potential roosts. Virginia big-eared bats used rock shelter large entrances and deep passages as feeding roosts. Entrance height, entrance width, shelter depth, shelter width explained most of the variation in the data. Discriminant function analysis of shelter on external (P = 0.0006) and internal (P = 0.0001) variables, separately, were significant. However, set of variables reliably classified shelters from an independent data set into feeding roosts or no data suggest that Virginia big-eared bats used a wide range of roost sites in DBNF, and that manager protect cliff habitats, especially those with a high density of rock shelters., A study of the use of cliff habitat by the Virginia big-eared bat (Plecotus townsendii virginianus) in the Daniel Boone National Forest (DBNF), Kentucky, reveals that the bats use cliff shelters as feeding roosts. Rock shelters with wide entrances and deep passages are chosen. The cutting of trees in the area should be avoided since bats are sensitive to disturbance.

Food habits of the endangered Virginia big-eared bat (Plecotus townsendii virginianus) were determined by analyzing guano and culled parts of insects collected in 1988 and 1989 from three maternity caves in eastern West Virginia. Food availability was evaluated by light-trapping at forest edge and forest interior sites in the vicinity of the caves. Lepidoptera was the most important insect order in the diet, followed by Coleoptera, Diptera, and Hymenoptera. Significant differences among bats from the different caves were observed in the percentage volume and frequency of Lepidoptera, Coleoptera, Diptera, and Hymenoptera. Bats selectively consumed Lepidoptera and avoided Coleoptera. Volume and frequency of Lepidoptera, Hymenoptera, and Coleoptera in the diet were positively related to their abundance in the forest interior. Patterns of consumption of Diptera paralleled abundance at the forest edge. Lepidoptera wings accounted for 90% of culled insect parts, 70% of which were from larvae that developed in forests.

Previous studies on size patterns within frugivorous and insectivorous bat guilds from northeastern Brazil suggest significant ecological separation of species. Nonetheless, recent simulation studies indicate that stochastic processes alone, rather than competition or coevolution, account for the morphological structure of these communities. To evaluate the dietary consequences of observed morphological structure, monthly samples of bats were collected (September 1976-May 1978) within edaphic Cerrado habitats on the Chapada do Araripe in northeastern Brazil. For each of the 11 most common species, stomach contents were identified, and the diets characterized for wet and dry seasons. Nonparametric statistical analyses of dietary constituents revealed two non-overlapping groups of frugivores based upon a posteriori contrasts: those that specialize on one food source, Vismia sp. (Carollia perspicillata, Artibeus planirostris, A. lituratus), and those that are more generalistic in their feeding habits (Glossophaga soricina, Sturnira lilium, Vampyrops lineatus). Statistical analyses of insectivorous species produced a homogeneous group (Anoura geoffroyi, Phyllostomus discolor, P. hastatus, Molossus molossus) based on classification of diet into hard-bodied versus soft-bodied insects. Like the ecomorphological assessments of community structure, our results failed to detect pervasive dietary differences among species that are related to size considerations.

We investigated whether a diet of a commonly eaten insect, June beetles (Phyllophaga rugosa), could meet the daily nutritional requirements of pregnant big brown bats, Eptesicus fuscus. In mid-pregnancy, ingestion of 34 culled June beetles meets daily caloric requirement and yields intakes of water, magnesium ([Mg.sup.2+]), potassium ([K.sup.+]), and nitrogen (N) that meet or exceed nutritional needs. Sodium ([Na.sup.+]) and total iron intake are marginally adequate, and calcium ([Ca.sup.2+]) intake is 10 times below estimated requirements.

The major foods of evening bats Nycticeius humeralis in Clay County, Indiana, were beetles, moths and leafhoppers, comprising 60, 19.7 and 7.0% of the total volume of food, respectively. The species eaten in greatest quantity (14.2% total volume) was the pest, Diabrotica undecimpunctata, the spotted cucumber beetle (its larva is the southern corn rootworm). The carabid beetle, Calathus sp., was also important, and the two most important cicadellids were Draeculacephala antica and Paraphlepsius irroratus. Stinkbugs (Pentatomidae) and chinchbugs (Lygaeidae) were other important foods. Bats in this colony ate ca. 6.3 million insects per year.

ABSTRACT. Big brown bats (Eptesicus fuscus) in Indiana feed heavily on agricultural pest insects. Big brown bats at Crane Naval Surface Warfare Center, Martin County, Indiana, where agricultural fields were [...]