Adult Bats Research Articles

Sexual Dimorphism in Big Brown Bat (Eptesicus fuscus) Ultrasonic Vocalizations is Context Dependent

Although bats are well known for their use of ultrasound for echolocation, there is limited evidence for its use in a social context. We tested whether ultrasonic vocalizations in bats were contextually (roosting or flying) sexually dimorphic. During the reproductive season, we recorded ultrasonic signals of captive adult male and female big brown bats while the bats were flying on tether lines in the field, and compared these signals to ultrasonic vocalizations made while roosting in an anechoic chamber. Principal component analysis reduced 7 ultrasonic call descriptors to 2 components that related to frequency (PC1) and time or shape (PC2). While bats were roosting, ultrasonic call components related to time or shape and frequency were both sexually dimorphic, being increased in males in each instance. However, when bats were recorded while flying, these same call components were no longer sexually dimorphic. This finding suggests that bats are changing their ultrasonic calls in relation to functional context, making them monomorphic and utilitarian for activities such as foraging and navigation, but dimorphic in a situation when mating activity is likely.

The microstructure of lingual papillae in the Egyptian fruit bat (Rousettus aegyptiacus) as observed by light microscopy and scanning electron microscopy

The microstructure of lingual papillae on the dorsal surface of the tongue of adult Egyptian fruit bats was examined by light microscopy (LM) and scanning electron microscopy (SEM). This elongated tongue with a rounded apex is approximately 3 cm long -- including the 1.7cm length of the anterior free part of the tongue -- which facilitates considerable freedom of movement. The surface of the tongue has four types of lingual papillae: two types of mechanical papillae -- filiform and conical papillae, and two types of gustatory papillae -- fungiform and vallate papillae. Most numerous are filiform papillae with well developed keratinized processes represented by four morphological subtypes -- small, giant, elongated, and bifid papillae. Our observations showed the small and giant filiform papillae to be present in the anterior part of the tongue and tilted to the back of the tongue. In the posterior part of the tongue, the filiform papillae with elongated processes were arranged on each side of the tongue and oriented perpendicularly to the median line of tongue. This arrangement of filiform papillae is considered to be useful for the efficient uptake of semiliquid food as it can be collected toward the median line of the tongue. Gustatory fungiform papillae were distributed among filiform papillae on the border of the apex and the anterior part of the body of the tongue and also on the posterior part of the tongue, while three vallate papillae surrounded by conical papillae were found on the root of the tongue. There were also taste buds along the ducts of the posterior lingual glands in the posterior-lateral part of the tongue. These morphological features are discussed in relation to adaptation to food uptake in the Egyptian fruit bat.

Roosting ecology and variation in adaptive and innate immune system function in the Brazilian free-tailed bat (Tadarida brasiliensis)

Bats have recently been implicated as reservoirs of important emerging diseases. However, few studies have examined immune responses in bats, and even fewer have evaluated these responses in an ecological context. We examined aspects of both innate and adaptive immune response in adult female Brazilian free-tailed bats (Tadarida brasiliensis) at four maternity roosts (two natural caves and two human-made bridges) in south-central Texas. Immune measurements included in vitro bactericidal ability of whole blood and in vivo T cell mediated response to mitogenic challenge. Bactericidal activity in T. brasiliensis varied with roosting ecology, but appears to be sensitive to colony-level effects. Blood from females living at one cave had significantly lower bactericidal ability than blood from females at three other sites. T cell mediated response in this species was associated with variation in roost ecology, with females from two caves having greater responses than females from two bridges. T cell mediated response and bactericidal activity were negatively correlated with one another within individuals that were tested for both. Variation in immunological response of T. brasiliensis is important for understanding the influence of the environment on the frequency and distribution of immunologically competent individuals and for understanding disease-host dynamics in this and other colonial species.

Male Seminole Bat Winter Roost‐Site Selection in a Managed Forest

Abstract: Understanding year‐round roost‐site selection is essential for managing forest bat populations. From January to March, 2004 to 2006, we used radiotelemetry to investigate winter roost‐site selection by Seminole bats (Lasiurus seminolus) on an intensively managed landscape with forested corridors in southeastern South Carolina, USA. We modeled roost‐site selection with logistic regression and used Akaike's Information Criterion for small samples (AICc) and Akaike weights to select models relating roost‐site selection to plot‐ and landscape‐level variables. We tracked 20 adult male bats to 71 individual roosts. Bats used a variety of roosting structures, including the canopy of overstory trees, understory vegetation, pine (Pinus spp.) needle clusters, and leaf litter. Roost height, structure type, and habitat type were influenced by changes in minimum nightly temperature. On warmer nights, bats selected taller trees in mature forest stands, but when minimum nightly temperatures were <4° C, bats typically were found roosting on or near the forest floor in mid‐rotation stands. We recommend avoiding prescribed burning in mid‐rotation stands on days when the previous night's temperature is <4 °C to minimize potential disturbance and direct mortality of bats roosting on or near the forest floor. We encourage forest managers to incorporate seasonal changes in roost‐site selection to create year‐round management strategies for forest bats in managed landscapes.

Diurnal Roosts of Male Evening Bats (Nycticeius Humeralis) in Diversely Managed Pine-Hardwood Forests

We examined attributes of 45 roost sites used by 17 adult male evening bats (Nycticeius humeralis) in a diverse forested landscape within the Ouachita Mountains, Arkansas. Bats roosted in a diverse array of substrates, including live or dead Pinus echinata ≥15 cm diam at breast height (29% of roosts) and small (<10 cm) understory or midstory hardwoods (20% of roosts). Sixty-three percent of roosts were in snags, 29% in live trees and 8% were on or near the ground. One roost was located in tree foliage, one in leaf litter and one was underground in what appeared to be a small-mammal burrow. Logistic regression models indicated that sites surrounding roosts were more likely to have fewer stumps and more hardwoods snags ≥10 cm diam at breast height than random sites. At the forest-stand level, all roosts were in stands with a mature (>50 y old) overstory. Twenty-six roosts (58%) were in stands that had undergone partial harvest, midstory removal and burning within the last 6 y, but 13 (50%) of those roosts were in unharvested inclusions (greenbelts) retained along stream drains within these stands; thus, 71% of all roosts were in unharvested patches of forest. Male evening bats were flexible in their roost selection, using a range of tree types (both live and dead), sizes and forest habitats. Possibly because cooler sites allow more frequent use of torpor during summer, they often roosted in small understory snags and in closed-canopy forest stands where these small snags were abundant. However, they also roosted in partially harvested portions of stands where a mature overstory was retained. Our results suggest that management intended to provide optimal roosting sites for females may not be applicable to male evening bats.

Torpor Use by Free-Ranging Pallid Bats (Antrozous pallidus) at the Northern Extent of Their Range

Abstract Torpor minimizes energy expenditure and water loss during periods of inclement weather, low prey availability, or both, and appears especially important in harsh environments such as deserts. We investigated use of torpor by free-ranging adult male pallid bats (Antrozous pallidus) at the northern limit of their range in the semiarid Okanagan Valley in British Columbia, Canada. We predicted that males would use torpor frequently during the active season and that ambient temperature (Ta) as well as nutritional condition (body condition index [BCI]) would affect torpor use. We expected roost microclimate to be conducive to daily heterothermy given that roosts had cool morning temperatures that increased in the afternoon. We used temperature-sensitive radiotransmitters to measure skin temperature (Tskin) of 8 bats from June to August 2003. Seven individuals used torpor each day (n = 54 tracking days) but not at night. Torpor duration increased as mean daytime Ta decreased albeit the relationship diff...

Sex-Specific Summer Roost-Site Selection by Seminole Bats in Response to Landscape-Level Forest Management

Although importance of forested corridors to navigating and foraging bats has been documented, the relationship between corridors and roost-site selection has not been studied. From late May to mid-August 2003–2006, we used radiotelemetry to investigate roost-site selection by Seminole bats (Lasiurus seminolus) on an intensively managed landscape with forested corridors in southern South Carolina. We tracked 27 (10 males and 17 females) adult Seminole bats to 90 (41 males and 49 females) diurnal roosts. We found 61% (n ¼ 25) of male and 63% (n ¼ 31) of female roosts in forested corridors, which comprised 11% of the landscape. We modeled roost-site selection with logistic regression and used Akaike’s information criterion for small samples (AICc) and Akaike weights to select models relating roost-site selection to landscape-level features. Our results indicated that several factors (i.e., distance to nearest corridor and distance to nearest mature pine stand) influenced roost-site selection and that differences existed between males and females, and among female reproductive condition. Examination of our data suggests that landscape-level features are more important than tree- and plot-level characteristics for roosting by Seminole bats on this managed forest. Corridors may represent a feasible approach to maintaining suitable roosting habitat for Seminole bats in managed forest landscapes.

Antiphonal calling allows individual discrimination in white-winged vampire bats

Mother bats use pup contact calls (‘isolation calls’) to find and recognize their young. In white-winged vampire bats, Diaemus youngi, adults produce social calls that are structurally similar to the pup isolation calls of many other bat species. In addition, D. youngi seem to exchange these calls in a duet-like fashion. To determine whether calls elicit precise antiphonal responses, we simultaneously recorded social calls from groups of four captive bats vocally interacting. To examine call function, we conducted isolation experiments, permuted discriminant function analyses (pDFA) of individual variation in call structure, and a habituation–discrimination playback experiment. We found that adult D. youngi call when isolated, and their social calls attract conspecifics and elicit antiphonal responses. Bats called within 500 ms of a conspecific more than expected based on a random calling model. These findings are the first evidence of antiphonal calling among adult bats. We found significant individual variation in call structure, and show that bats can discriminate individual identity using social calls alone. We hypothesize that D. youngi use these antiphonal contact calls to mediate social interactions among individuals outside the roost.

EXPERIMENTAL RABIES VIRUS INFECTION OF BIG BROWN BATS (EPTESICUS FUSCUS)

A captive colony of adult Big Brown Bats (Eptesicus fuscus) was experimentally infected with a rabies virus (RABV) variant isolated from the salivary glands of a naturally infected Big Brown Bat and passaged once through murine neuroblastoma cell culture. Bats were divided into 11 groups, which were composed of one to three noninfected and one to three infected individuals each. Twenty of 38 animals were infected intramuscularly into both left and right masseter muscles; they received a total of 10(3.2) median mouse intracerebral lethal dose (MICLD50) of Big Brown Bat RABV variant. Experimental outcome after viral exposure was followed in the bats for 140 days postinoculation (PI). Of 20 infected bats, 16 developed clinical rabies, and the mean incubation period was 24 days (range: 13-52 days). Three infected bats never seroconverted and succumbed early to infection (13 days). Four infected bats that survived until the end of the experiment without any signs of disease maintained detectable antibody titers until the third month PI, peaking between days 13 and 43, and consequent drop-off below the threshold for detection occurred by day 140. Limited excretion of virus in saliva of infected bats during the clinical course of disease was observed in two individuals on days 13 and 15 PI (<24 hr prior to onset of clinical illness). No bat-to-bat transmission of RABV to noninfected bats was detected.

Little Brown Bats (Myotis lucifugus) Recognize Individual Identity of Conspecifics Using Sonar Calls

AbstractBats use sonar calls to locate prey and orient in their environment but they may also be used by conspecifics to obtain information about a caller. Statistical analysis of sonar calls provides evidence that variation carries social information about a caller, including individual identity. We hypothesized that little brown bats (Myotis lucifugus) would be able to recognize individuals given the potential fitness benefits of doing so. We performed playback trials using a habituation‐discrimination design to determine whether little brown bats are able to recognize the individual identity of a caller based on variation in their sonar calls. Each subject bat was played the calls of bat A until they habituated (defined as a 50% decrease from the beginning call rate), then the calls of bat B or a new call sequence of bat A (a control, referred to as bat A’) were played. Each subject received a unique pair of playback recordings (bat A and B) from adult female bats from the same colony (but a different colony from the subject) and the order of trials was randomized. The response measures were habituation time (s) and call rate (calls/s). Within a trial, subjects habituated to calls of bat A and transferred this habituation to the bat A’ sequence. In addition, they increased their call rates when played calls of bat B. Comparing between trials, subjects increased their call rate to the calls of bat B to a greater relative extent than to the calls of bat A’. These results provide the first evidence that bats recognize individual identity of conspecifics (as opposed to discrimination of groups), which has implications for the social interactions of bats.

I Did It My Way: Women Remaking American Judaism (review)

Reviewed by: I Did It My Way: Women Remaking American Judaism Ronit Irshai (Naamat) (bio) I Did It My Way: Women Remaking American Judaism. Edited by Riv-Ellen Prell. Detroit: Wayne State University Press, 2007. xii + 331 pp. The editor of this collection of essays, Riv-Ellen Prell, characterizes the volume as a product of the “thirty-five-year gestation of American Jewish feminism” (1). The feminist movement has brought about profound changes of form and content in religious life, and the book aims to portray those changes on several planes, treated in its three sections. Part one of the book, “Reenvisioning Judaism,” deals with the new feminist theology—an enterprise that boldly exposed the intense patriarchal biases of the biblical and rabbinic traditions but also found novel ways of understanding the lives of women by reading between the lines of the Bible and expounding on its omissions. More broadly, it has proposed a fundamental revision of Jewish theology, including its concept of God and its understanding of revelation. Part two, “Redefining Judaism,” examines feminism’s influence at the local, practical level, and considers its effects on various Jewish denominations. Taking an historical-cultural approach, the article on Reform Judaism examines how that movement’s communal practice has been affected by changes in the general culture that have afforded women more nearly equal standing. The article on Reconstructionism emphasizes Mordecai Kaplan’s religious philosophy and how the concept of Judaism as a civilization—or, more precisely, of Jewish “folkways”—paved the way to gender equality. The article on Conservative Judaism shows how efforts to find “local” halachic solutions to gender issues evolved into a broader transformation of moral consciousness itself. That transformation allowed for changes in synagogue ritual and, eventually, for the ordination of women as rabbis. Change within Orthodoxy proceeds more gradually, and the article on that denomination therefore focuses on the revolution in Torah study by women and on women’s prayer groups. The article comes to a dead end, however, when it turns to the issue of mesoravot get—women whose husbands refuse to grant them a desired divorce (and thereby prevent them from remarrying according to Jewish law). Sounding a pessimistic note, Norma Baumel Joseph writes that “the transformations listed above [with respect to Torah study and prayer groups] emanate from the Jewish desire for increased knowledge and involvement. But with divorce the basic claims of justice in Judaism are most severely challenged . . . ” (203). Still, she believes that the new generation of female halachic scholars will pose a radical challenge to rabbinic authority, and I think it fair to conclude that the situation may well change, albeit slowly. [End Page 126] While the other writers in this part consider specific movements within Judaism, Pamela Nadell, in her essay on the first generation of women rabbis, assesses the revolution wrought by the ordination of women as rabbis from a cross-denominational perspective. That step, in her view, provides one of the answers to the question posed by the book as a whole, namely, how it was possible for so many feminist innovations to enter the Jewish mainstream so quickly. Women rabbis, she argues, served in the front lines and were the first to adopt these changes and make them acceptable within communal life. Part three of the book, “Reframing Judaism,” is devoted to distinctively feminine rituals that developed over the years, both within the synagogue and without. These include Rosh Chodesh (New Moon) celebrations; ritualization of the figure of Miriam through the addition of “Miriam’s cup” to the Passover Seder and the adoption of “Miriam’s Tambourine” as an element of the Seder and of Rosh Chodesh; bat-mitzvah celebrations; and the introduction of the adult bat mitzvah with its attendant effects on older women’s Jewish and community identity. The publication of this retrospective on thirty-five years of Jewish feminism in America is an exciting and meaningful event, for as recently as one hundred years ago—a short interval in historical time—most of the religious expressions and values associated with feminism could hardly be imagined. Taking a more critical perspective, however, I believe that the book would have benefited from an effort to...

Isolation of Novel Adenovirus from Fruit Bat (Pteropus dasymallus yayeyamae)

To the Editor: Bats are thought to be one of the most important reservoirs for viruses such as Nipah virus, severe acute respiratory syndrome (SARS) coronavirus, and Ebola virus (1). These pathogens became known after extensive surveys of bats following outbreaks. As a first step in investigating unidentified pathogens in bats and to help forecast the potential threat of emerging infectious diseases, we tried to isolate and characterize viruses that persistently infect bats. In the process, we isolated a novel adenovirus from a fruit bat in Japan. Pteropus dasymallus yayeyamae, or Ryukyu flying fox, is a fruit bat of Japan. With the permission of the governor of Okinawa, we caught 1 adult male bat of this species and used its spleen and kidneys to establish primary cell cultures. On the 4th passage of the primary adherent cells derived from the spleen, a cytopathic effect (CPE) appeared without any visible microbe, indicating that the cell culture contained a virus. The virus, tentatively named Ryukyu virus 1 (RV1), caused apparent CPE on primary kidney cells derived from a Ryukyu flying fox and on our established bat kidney T1 (BKT1) cells, which were derived from the kidney of a horseshoe bat (Rhinolophus ferrumequinum) and transformed with expression plasmid DNA encoding the large T antigen of replication origin-defective simian virus 40. To identify the virus, RV1, we applied the rapid determination of viral RNA (RDV) system version 1.0 (2). However, no viral nucleic acid sequence was detected from an RNA sample in the RV1-infected BKT1 cells. For detection of viral DNA, we developed a system for rapid determination of viral DNA sequences (RDV-D) by minor modification to the RDV system for RNA viruses (2–4). The results indicated that 2 of the fragments were homologous to the gene encoding the precursor of terminal protein (pTP) of adenoviruses. Further RDV-D analysis showed that 6 fragments (139 bp, DDBJ/EMBL/GenBank accession no. {type:entrez-nucleotide,attrs:{text:AB302970,term_id:159576533,term_text:AB302970}}AB302970) were homologous to the pTP gene and that another 6 fragments (316bp, DDBJ/EMBL/GenBank accession no. {type:entrez-nucleotide,attrs:{text:AB302971,term_id:159576535,term_text:AB302971}}AB302971) were homologous to the gene encoding the precursor of protein VI (pVI) of adenoviruses. These results indicated that RV1 must belong to the family Adenoviridae. To further confirm that RV1 isolate was an adenovirus, we used PCR and sequencing. We performed the first reaction with the outer primer pair (polFouter and polRouter) of a nested PCR method, targeting the viral DNA polymerase gene with highly degenerate consensus primers that have been described recently (5). A fragment of ≈550 bp was amplified from RV1 as well as from human adenoviruses-1, -3, -4, and -7 (data not shown). Sequence analysis of the amplified product (DDBJ/EMBL/GenBank accession no. {type:entrez-nucleotide,attrs:{text:AB303301,term_id:159885613,term_text:AB303301}}AB303301) showed that RV1 was homologous to tree shrew adenovirus 1 (70.0% amino acid sequence identity), porcine adenovirus 5 (69.2%), canine adenovirus 1 (68.9%), human adenoviruses-3, -16, -21 and -50 (68.9%), and other viruses (>64.8%) in genus Mastadenovirus, but less homologous (46.7%–57.8%) to viruses in other genuses, Siadenovirus, Aviadenovirus, and Atadenovirus. In addition, a phylogenic tree based on amino acid sequences indicated that RV1 belongs to family Adenoviridae, genus Mastadenovirus (Figure). Figure Phylogeny of adenoviruses based on analysis of partial amino acid sequences of DNA polymerase protein. Trees were estimated by using the neighbor-joining method based on the amino acid pairwise distance and MEGA 4.0 software (www.megasoftware.net). Numbers ... Electron microscopy of RV1-infected BKT1 cells indicated that RV1 accumulated in the nucleus and that the size of capsids was 60–70 nm (data not shown). Restriction endonuclease analysis of the RV1 genome indicated that the genome was ≈20–30 kbp (data not shown). These features are consistent with RV1 being an adenovirus. Until now, a number of RNA viruses have been isolated from bats, but isolation of DNA virus is rare (1). The isolation of the novel adenovirus seems to be possible because of usage of the primary cells originated from the host; DNA viruses might have more restricted host range than RNA viruses and require host-originated cells for the growth. In addition, our success in DNA virus isolation might have resulted from usage of the adult animal latently and persistently infected with DNA viruses such as adenovirus and herpesvirus. In conclusion, we isolated a novel virus from a fruit bat. This virus was isolated from a healthy bat, which suggests that the virus may persistently infect fruit bats. Although its pathogenicity for humans is still unknown, knowledge of RV1 will be useful in epidemiologic studies of infectious diseases emerging from bats because persistently infecting viruses might be isolated together with primary pathogens. We are planning to establish cell lines from bats and isolate more viruses from persistently infected bats.

Neuronal connexin expression in the cochlear nucleus of big brown bats

We present immunohistochemical data describing the presence and distribution of connexins, structural component of gap junctions, in the cochlear nuclei of adult big brown bats ( Eptesicus fuscus). Echolocating big brown bats show microsecond scale echo-delay sensitivity that requires accurate synchronization of neuronal responses to the timing of echoes. Midbrain and auditory cortical neuronal response timing is similar to that observed in other non-echolocating mammals, suggesting that lower auditory processing nuclei may have specialized mechanisms for obtaining the required temporal hyperacuity. Our data shows that connexin 36, a gap junction protein specific to neurons, is most densely expressed in the bat's cochlear nuclear complex, the medullary region that receives and processes first-order afferents from the auditory nerve. Cx36 expression is absent in the cochlear nucleus of normal mice, which have high-frequency hearing sensitivity similar to big brown bats. Glial connexins, Cx26 and Cx43, expressed in astrocytes and several inner ear structures, are also found in the bat cochlear nucleus complex, associated with major fiber tracts in and around the cochlear nuclei. The extensive presence of neuronally-associated Cx36 in brainstem auditory structures of adult bats suggests a possible role for gap junctions in mediating echo-delay hyperacuity.

Spatial and Temporal Patterns ofZaire ebolavirusAntibody Prevalence in the Possible Reservoir Bat Species

To characterize the distribution of Zaire ebolavirus (ZEBOV) infection within the 3 bat species (Epomops franqueti, Hypsignathus monstrosus, and Myonycteris torquata) that are possible reservoirs, we collected 1390 bats during 2003-2006 in Gabon and the Republic of the Congo. Detection of ZEBOV immunoglobulin G (IgG) in 40 specimens supports the role of these bat species as the ZEBOV reservoirs. ZEBOV IgG prevalence rates (5%) were homogeneous across epidemic and nonepidemic regions during outbreaks, indicating that infected bats may well be present in nonepidemic regions of central Africa. ZEBOV IgG prevalence decreased, significantly, to 1% after the outbreaks, suggesting that the percentage of IgG-positive bats is associated with virus transmission to other animal species and outbreak appearance. The large number of ZEBOV IgG-positive adult bats and pregnant H. monstrosus females suggests virus transmission within bat populations through fighting and sexual contact. Our study, thus, helps to describe Ebola virus circulation in bats and offers some insight into the appearance of outbreaks.

Summer Roosting by Adult Male Seminole Bats in the Ouachita Mountains, Arkansas

We used radiotelemetry to locate 51 diurnal roosts for 17 male Seminole bats (Lasiurus seminolus) during late spring and early summer, 2000–2005. We quantified characteristics of roost trees and sites surrounding roosts and compared those measurements with random trees and random locations. All but two roosts were located in the foliage of large overstory pines (Pinus sp.). All roosts were in trees ≥21.7 cm dbh and roost trees were taller and greater in diameter than random trees. A conditional logistic regression model differentiating roost sites from random locations indicated Seminole bats were more likely to roost at sites with more pines 25.0–49.9 cm dbh, fewer pines 10.0–24.9 cm dbh, lower overstory hardwood basal areas (BA) and more recently cut stumps than random; bats selected open forest sites dominated by large (>20.0 cm dbh) pines. Eighty-four percent of roosts were located in stands that were recently partially harvested or thinned but retained large overstory pines. Relatively open pine forest, with abundant large overstory pines, is important roosting habitat for male Seminole bats during summer on the western edge of their range.

Sex-specific roost selection by adult red bats in a diverse forested landscape

The eastern red bat ( Lasiurus borealis) is a common, widespread species that occurs throughout eastern North America; however, information on potential differences in roost selection between sexes is limited. We studied summer diurnal roosting of adult red bats in a diverse forested landscape to: (1) characterize roosts of adult males and females, (2) determine habitat relationships for both sexes, and (3) compare roost selection between the sexes. We radiotracked 21 male and 20 female red bats to 142 roost locations and quantified roost characteristics. Both sexes roosted mostly in overstory hardwoods (82% of male and 81% of female roosts), but males occasionally (8% of roosts) roosted in sapling (<5 cm diameter at breast height; dbh) whereas females did not. Females roosted at greater heights than males but, mean diameter and height of roost trees ≥5 cm dbh did not differ between sexes; roosts trees used by both sexes were greater in diameter and height than random trees. We found no difference between sexes in tree species used for roosting; both sexes preferred to roost in white oaks ( Quercus alba) and hickories ( Carya spp.) but avoided Pines ( Pinus spp.). Sex-specific habitat models created using an information-theoretic approach indicated males were more likely to roosts at sites with more midstory (5–10 cm dbh) and small overstory (10–25 cm dbh) hardwoods, taller hardwoods, shorter pines, and further from the nearest tree than random. Females were more likely to roost at sites with more midstory hardwoods, fewer small overstory pines (10–25 cm dbh), and fewer understory (<5 cm dbh) woody stems than random. Comparisons of mean habitat parameters surrounding roost sites indicated only distance to nearest tree differed ( P < 0.05) between sexes; females roosted further from the nearest tree than males. Ninety-five percent of male roosts and 92% of female roosts were in stands dominated by mature (≥50 years old) trees, and 45% of male roosts and 40% of female roosts were in stands that had been partially harvested 1–5 years earlier but retained mature overstory hardwoods. Retaining minimum basal areas of 1.1–2.3 m 2/ha of overstory hardwoods and retaining unharvested buffers along stream drains in harvested areas would likely provide adequate roosting habitat for both sexes of red bats in managed landscapes during summer.

Dados de reprodução de Platyrrhinus lineatus em estudo de longo prazo no Estado do Rio de Janeiro (Mammalia, Chiroptera, Phyllostomidae)

Baseado em uma grande amostragem de morcegos realizada na Mata Atlântica, Estado do Rio de Janeiro, sudeste do Brasil, nós analisamos a biologia reprodutiva de Platyrrhinus lineatus (E. Geoffroy, 1810). Os morcegos foram capturados com redes de neblina entre 1989 e 2005, em 27 das 41 diferentes localidades amostradas. O começo da época reprodutiva foi estimado 30 dias antes da data da captura da primeira fêmea grávida. Para determinação do término da época reprodutiva empregamos a data da captura da última fêmea lactante mais 40 dias. O total de 688 morcegos adultos foi analisado, sendo 58,3% representados por fêmeas. O maior número de capturas foi observado nos meses de fevereiro, janeiro e agosto. Machos com testículos escrotados foram observados em todos os meses. Fêmeas inativas sexualmente foram observadas com predominância em março e de maio a agosto. Fêmeas com fetos palpáveis foram observadas em todos os meses, exceto em abril, junho e julho com pico em agosto-outubro e janeiro-fevereiro. Fêmeas lactantes foram capturadas de novembro a junho, com pico em novembro e fevereiro. Fêmeas simultaneamente grávidas e lactantes foram capturadas em todos os meses exceto em junho, com pico em abril. O tamanho da época reprodutiva variou a cada ano, compreendendo de 8 a 12 meses, com média de 10,6 meses.

Ecological Correlates of Range Size in the Tent-Making BatArtibeus watsoni

We examined variation in foraging- and roosting-range size in the tent-making bat Artibeus watsoni .W e radiotracked 42 individuals at 2 sites in the Golfito Wildlife Refuge and 6 sites at Corcovado National Park, southwestern Costa Rica. Average home-range size of A. watsoni was the smallest recorded for a bat species (3.6 ha). Site, age, reproductive status, habitat, and season all had significant effects on foraging ranges, but sex and population abundance did not. Bats from the most productive sites, such as primary forests, had smaller foraging ranges, and subadults ranged farther than adults. During the dry season, females in late pregnancy had the smallest foraging ranges of all, most likely as a result of flight constraints imposed by the large fetus and an increase in fruit availability. Conversely, lactating females sampled during the early rainy season had among the largest foraging ranges. Males had significantly smaller roosting ranges than females, and adult bats sampled from areas of low roost abundance and high population abundance had smaller roosting ranges. However, subadults appeared to be unaffected by such changes in resource abundance, perhaps because they often roost in unmodified leaves. Although differences in resource availability and competition were important in determining roosting-range size, these effects were concealed by effects of reproductive activities such as mating, pregnancy, and lactation. Reproductive condition, along with foraging and roosting resource abundance, were largely responsible for determining ranging patterns in A. watsoni, but factors influenced foraging- and roosting-range size in different ways.

Contribution of NMDA and AMPA Receptors to Temporal Patterning of Auditory Responses in the Inferior Colliculus

Although NMDA receptors (NMDARs) are associated with synaptic plasticity, they form an essential part of responses to sensory stimuli. We compared contributions of glutamatergic NMDARs and AMPA receptors (AMPARs) to auditory responses in the inferior colliculus (IC) of awake, adult mustached bats. We examined the magnitude and temporal pattern of responses to tonal signals in single units before, during, and after local micro-iontophoretic application of selective antagonists to AMPARs [NBQX (1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide)] and NMDARs [CPP ((+/-)3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid)]. Combined blockade of AMPARs and NMDARs eliminated excitatory responses in nearly all neurons, whereas separate blockade of each receptor was quantitatively similar, causing substantial (> 50%) spike reductions in approximately 75% of units. The major result was that effects of receptor blockade were most closely related to the first-spike latency of a unit. Thus, AMPAR blockade substantially reduced spikes in all short-latency units (< 12 ms) but never in long-latency units (> or = 12 ms). NMDAR blockade had variable effects on short-latency units but reduced spikes substantially for all long-latency units. There were no distinct contributions of AMPARs and NMDARs to early and late elements of responses. Thus, AMPAR blockade reduced early (onset) spikes somewhat more effectively than NMDAR blockade in short-latency units, but NMDAR blockade reduced onset spikes more effectively in long-latency units. AMPAR and NMDAR blockade were equally effective in reducing later elements of sustained responses in short-latency units, whereas NMDAR blockade was much more effective in long-latency units. These results indicate that NMDARs play multiple roles for signal processing in adult IC neurons.

Development of functional organization of the pallid bat auditory cortex

The primary auditory cortex is characterized by a tonotopic map and a clustered organization of binaural properties. The factors involved in the development of overlain representation of these two properties are unclear. We addressed this issue in the auditory cortex of the pallid bat. The adult pallid bat cortex contains a systematic relationship between best frequency (BF) and binaural properties. Most neurons with BF <30 kHz are binaurally inhibited (EO/I), while most neurons with BF >30 kHz are monaural (EO). As in other species, binaural properties are clustered. The EO/I cluster contains a systematic map of interaural intensity difference (IID) sensitivity. We asked if these properties are present at the time the bat acquires its full audible range (postnatal day [P] 15). Tonotopy, relationship between BF and binaural properties, and the map of IID sensitivity are adult-like at P15. However, binaural facilitation is only observed in pups older than P25. Frequency selectivity shows a BF-dependent sharpening during development. Thus, overlain representation of binaural properties and tonotopy in the pallid bat cortex is remarkably adult-like at an age when the full audible range is first present, suggesting an experience-independent development of overlapping feature maps.