Caves are very important roosts for bats. Neotropical countries, like Brazil, harbor both high bat species richness and abundance of underground cavities. The Caatinga drylands in northeastern Brazil are a good example with potentially 100 bat species and a high number of caves. Among those caves, some harbor exceptionally large bat populations, but, even thus, they still remain poorly known and studied. Here we present a 48-months monitoring based on a non-invasive thermal detection system to estimate the abundance changes of a large colony in a bat cave in the Caatinga drylands of Brazil. That cave harbors ten bat species — two nationally endangered — and 70% of them are main cave users. We found a marked inter-month fluctuation in the total bat abundance, with no consistent pattern. Total bat abundance was neither related to precipitation nor to the reproductive seasonality. During certain moments, the bat population can reach up to 120,000 individuals, making this cave a priority site for bat conservation in Brazil.

Population size and survival are crucial factors to understand population dynamics of a given species, especially those that have long life spans and delayed sexual maturity, such as Pteropodidae bats. We studied the population size and apparent survival of individuals at a day roost site of an endemic cave-dwelling Malagasy fruit bat, Rousettus madagascariensis, in relation with age and sex. 1,801 individuals were captured and tagged over the course of four years in the Grotte des Chauves-souris, Reserve Speciale d'Ankarana, northern Madagascar. The Cormack-Jolly-Seber model and the POPAN model in the program MARK were used to analyze mark-recapture data and to estimate apparent individual survival and population size. The apparent survival of individuals ranged from 0.46 to 0.60, but exhibited significant variability associated with age, sex, and time. Apparent survival is lower in adults compared to sub-adults (Φadult = 0.49; Φsub-adult = 0.63). For adults, the apparent survival of males was higher (Φmale = 0.50; Φfemale = 0.47), and conversely for sub-adults, it was in favor of females (Φmale = 0.55; Φfemale = 0.70). Population size ranged from 1,245 (CI: 268–3,050) to 5,868 (CI: 3,520–10,601) and was significantly higher during the wet season as compared to the dry season. The survival rate in this population is strongly influenced by mortality and secondarily by dispersal. We found that the apparent survival of individuals has a positive impact on population growth but less than birth rate. Thus, the health and sustainability of the population relies heavily on individual survival.

As bats are long-lived mammals, insight into the age of individuals is important for studies relating to population ecology and conservation biology, as well as longevity. Thus, there is a need to develop methods to estimate the age of bats, and teeth are excellent means to do so. The work detailed here involves an assessment of age-related changes and variation in tooth wear, dentine growth layers, and pulp cavity size in two bat species with differing life history strategies, i.e. Nyctalus noctula (n = 149) and Eptesicus serotinus (n = 49). Both the gross morphology and the histology of teeth in both species were found to display age-related variation. Morphological indicators like tooth wear and pulp-cavity size showed considerable variation at the individual level, and corresponding with broadly defined age categories. Dentine growth layering was consistent with presumed age and had annual growth layers in both species, along with accessory layers. Aspects of interpreting growth layers and tooth wear based on photographs and histological preparations associated with observer bias are important to consider, as are the sampling of multiple readings.

The long-toothed pipistrelle (Hypsugo dolichodon) was recently described as a new bat species based on four specimens from Laos and Vietnam. During investigations of taxa in the Vespertilionini tribe, we noted that specimens reported as Falsistrellus affinis (recently transferred to genus Hypsugo) from Myanmar and Cambodia have mtDNA sequences and craniodental characteristics similar to H. dolichodon and different from genuine H. affinis. Mitochondrial homogeneity within H. dolichodon was also apparent as there was no nucleotide difference between the widely distributed Cambodian, Lao and Vietnamese specimens in CO1 or Cytb genes. Although ecological data are scarce, H. dolichodon appears to be a cave-dweller which would suggest that conservation measures are a priority because tropical caves are under high pressure from human use.

This study investigated the reproductive dynamics of a colony of Geoffroy's tailless bat (Anoura geoffroyi), an important pollinating bat, in a highland area of Southeastern Brazil. The colony was monitored each month from November 2014 to December 2015 with 154 males and 117 females captured. Testicular and ovarian histological data from 31 adult males and 22 adult females were obtained. Body condition index of male and female, and gonadosomatic index, epididymis-somatic index and Sertoli cell efficiency were analyzed. Females with spermatozoa in uterine crypts, embryos in oviducts, gravid uteri, and pregnant females were registered during the rainy season (November-March) and into the beginning of the following dry season (April), indicating asynchrony of births. The ovaries showed all types of ovarian follicles, and a polarized ovary cortex was found, differing from the organization pattern of most mammals. The testes showed continuous spermatic activity, but testicular parameters analyzed showed significantly higher values during the rainy season. A shorter mating period during the beginning of this season was detected, when values of the gonadosomatic and epididymis-somatic indexes, and Sertoli cell efficiency showed more pronounced differences in relation to the remaining period of study. Unlike polyestry known for some Neotropical phyllostomids, the reproductive cycle of A. geoffroyi was characterized as seasonal monoestrous, with the main reproductive events occurring during the rainy season, as the best time for females to reproduce, but with offspring recruitment occurring predominantly during the dry season, a period with fewer food resources.

We studied, simultaneously, postnatal variation in ectoparasite load in neonates, lactating, pregnant and non-pregnant females — in a free-ranging nursing colony of Geoffroy's bat (Myotis emarginatus) in Kerend Cave, western Iran. During this survey we monitored 120 (78 ♂♂, 42 ♀♀) neonate bats, as well as 21 pregnant, 42 lactating and 15 non-pregnant females. These individuals yielded a total of 1857 wing mites of the species Spinturnix emarginata. The first 14 days following the birth of pups was found to be associated with a rapid increase in numbers of S. emarginata on the neonates — up to an average (± SE) 21.3 ± 5.34 ectoparasites per individual. This was followed by a sudden reduction in parasite load to a stabilised rate of 5.9 ± 0.98 parasites per individual at the end of the postnatal period. The average ectoparasite load for all neonates over 42 days of the postnatal period was 11.5 ± 0.81. No significant difference was noted as regards average parasite load for neonate males (11.9 ± 1.11) and f...

This study characterizes the patterns of bat fly parasitism on Cynopterus brachyotis, the most common fruit bat in the tropical urban environment of Singapore. Mist netting was conducted over a period of five months in two secondary forest sites, where 211 unique individuals were captured and examined for ectoparasites. The relative density, prevalence and mean intensity of parasitism by the wingless nycteriibid Leptocyclopodia ferrarii ferrarii were compared with respect to sex, age and reproductive status of captured bats. The overall prevalence of parasitism was 40.3% and analyses revealed no significant differences in the three parameters when comparisons were made between demographic subgroups. However, adults, females and pregnant females had a higher prevalence of infestation, while juveniles, males and non-pregnant females had higher mean intensity of bat flies. Roosting behavior is likely to be the driving factor for parasite transmission, as bat flies are more likely to encounter females because of C. brachyotis' harembased social structure. No correlation was found between bat body condition and parasite load, even when the relationship was examined for juveniles and adults separately. The observation of a re-infestation within 46 days suggests that there is high intraindividual and intra-roost parasite transmission. Research into roost group size, distribution, site fidelity, and connectivity is needed to better understand the patterns and dynamics of parasitism on bats living in the urban environment.

Worldwide species density of bats is highest in forests ecosystems. European primeval forests are now reduced to a few small and isolated patches because almost all forests are subject to management. Therefore, knowledge about bats in ancient and near-natural forests in Europe is scarce. In the well-preserved forest stands of the Belovezhskaya Pushcha National Park in Belarus we studied the bat community (1), the presence of maternity colonies and their preference in tree roost selection (2) and parameters of roosts used by forest dwelling bats (3). By mist-netting surveys, we identified 13 bat species and acoustic data suggested the presence of another three species. We detected 15 maternity colonies of seven bat species by radio-tracking reproductive females and 40 tree roosts within the forest. Roosts of Barbastella barbastellus, Pipistrellus pygmaeus and Plecotus auritus were almost exclusively behind the loose tree bark of decaying trees, or within narrow crevices. Myotis nattereri and Nyctalus leisleri showed a preference towards hollows (e.g., woodpecker-made cavities) within oak trees (Quercus robur). Our study shows that all tree-dwelling bat species are highly dependent on natural processes within forests that allow the formation of roost sites. Therefore, we strongly support that the natural aging process of trees, as well as the consequences of natural disturbance (e.g. through weather), should be permitted. This should extend beyond the protected zones of National Parks. In contrast, sanitary cuttings decrease the habitat's suitability for forest-dwelling bats. Finally, our results indicate that the forest complex of Belovezhskaya Pushcha and Białowieża is one of the most important bat areas in Europe.