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We describe a species of Chaerephon (Molossidae) new to science from western Madagascar. This bat differs from the other two Chaerephon occurring on the island and from comparably sized African and Asian Chaerephon based on measurements, pelage and wing coloration, and cranial and dental characters. Chaerephon sp. nov. occurs at three sites in the drier western portion of the island. We also provide some natural history and distributional information on other Malagasy members of this family.
The vocalizations of the Malagasy endemic fruit bat, Eidolon dupreanum (family Pteropodidae) were previously not documented. Individuals of this species, which make day roost sites in rock crevices or the dark zones within caves, were recorded while exiting a cave in the Parc National d'Ankarana. Individuals leaving a roost at dusk were recorded 200 m and 35 m inside the cave, as well as two sites outside the cave. Visible light in the cave dropped to 0 lux about 50 m from the entrance. While exiting, individuals flew within 50–100 cm of the ceiling, often settling and perching every 5–10 m along their flight patch and displacing in a leapfrog manner towards the cave entrance. Three distinct call types were identified: social calls 1, social calls 2 and echo clicks. Bats produce the echo clicks while flying towards the entrance, while the other two calls were emitted at roost sites and near the cave entrance. Although the results are preliminary, we suggest that the social calls 1 and 2 were employed for social communication, whilst echo clicks may have been used in a sensory context, potentially as incipient echolocation to navigate in the dark cave.
We present information on the morphological structure and measurements of the os penis for eight families and 28 species of bats occurring on Madagascar, most being endemic to the island. For one of these families, Miniopteridae, no bacular structure was found and for a second family, Emballonuridae, the structure was absent in one species (Taphozous mauritianus). For the majority of taxa, the descriptions and measurements given herein of their respective bacula are presented for the first time in the published literature. In cases when samples are sufficient for certain species, we examine intra-specific variation in bacular morphology. For species the subject of previous published phylogeographical studies and which showed clade structure associated with elevational or latitudinal clines, we investigate if intra-specific differences in bacular structure are correlated with clade associations. We examine possible correlates associated with os penis measurements and, in general, across all species or within certain families, there was not a clear correlation between body size, as measured by forearm length, and different bacular measurements.
Previous studies conducted on morphological variation of the endemic Malagasy bat Hipposideros commersoni sensu stricto (Hipposideridae) revealed a north-south morphological cline, with larger individuals present in the north. Little is known about potential sexual differences in the echolocation calls of this species. We captured 59 adult individuals (24 males and 35 females) at different sites spanning the western half of Madagascar, measured their forearm length and recorded echolocation calls. These data were used to examine possible variation in echolocation calls and body size, which showed statistically significant differences. Male H. commersoni have an average forearm length of 93.1 mm and emit calls at 68.6 kHz, while the average measurements for females are 83.9 mm and about 72.9 kHz, respectively. Principal component analysis revealed variation in morphological and bioacoustic parameters, suggesting a high intraspecific variation. Regression analysis of intersexual data showed that females from the far north (Ankarana) significantly deviate from the allometric relationship by emitting echolocation calls lower than predicted by their size. These divergences may be associated with phenotypic variation, migratory movements or presence of a possible cryptic species. Detailed phylogenetic and phylogeographical analyses of the H. commersoni complex are needed to address these questions.
Six species of small vespertilionid bat were recently collected in Madagascar. Neoromicia matroka (included by some in Eptesicus) and N. malagasyensis were already recorded from the island. Pipistrellus hesperidus was known but under a different name, P. kuhlii. Neoromicia melckorum is a new species record for the island. Hypsugo anchietae represents a new species and genus record. The last taxon is a previously undescribed species of Pipistrellus, which shows affinities to three South-east and East Asian pipistrelle taxa. In this paper, the new species is described and further information on the taxonomy, distribution, ecology, and behaviour of all six taxa are provided.
Patterns of interspecific and intraspecific variation in the three endemic species of Malagasy Triaenops bats were investigated using morphology and bioacoustics. Adult bats were captured at different localities across the island, measured, and their echolocation calls recorded. On average, male T. auritus and T. furculus have shorter forearms (47.0 and 44.0 mm, respectively) and emit higher frequency calls (107.8 and 113.1 kHz, respectively) than females (47.5 and 45.7 mm and 95.6 and 98.2 kHz, respectively), representing a form of reversed sexual dimorphism (females larger than males). However, T. menamena shows typical patterns of sexual size dimorphism with males having a longer forearm (51.7 mm) and lower frequency echolocation calls (82.3 kHz) than females (49.0 mm and 93.5 kHz, respectively). When segregated by sex, there was a strong allometric relationship between forearm length, used as a measure of body size, and the resting frequency in these three species, as well as two African hipposiderids (T. afer and Cloeotis percivali). Triaenops auritus males and both sexes of T. furculus deviated from the relationship between these two variables. Hypotheses are explored to explain the drivers of these sexual dimorphism patterns. On the basis of the allometric relationship, the strong correlation is in parallel to other groups of bats and is probably associated with ecological constraints. Recent phylogenetic analyses showed a separation of Afro-Malagasy Triaenops into two sister clades: T. auritus/T. furculus (suggested to be placed in a new genus, Paratriaenops) and T. menamena/T. afer. The patterns of sexual dimorphism in these taxa are congruent with clade membership. Further studies are needed to understand strategies used by these taxa when in sympatry to share habitat and ecological niches.
We describe a new species of Scotophilus (Vespertilionidae) from western Madagascar. This bat differs from the other members of this genus known from the island, Africa, and Asia based on its notably diminutive size, pelage coloration, and tragus shape and length. Scotophilus sp. nov. is known from seven different specimens taken at three different sites in the central western portion of the island, in zones with anthropogenic savanna dominated by palms (Bismarckia nobilis) and dry deciduous forest. The holotype was collected in the palm leaf roof of a thatched dwelling, which is the first evidence of the synanthropic occurrence of a member of this genus on Madagascar. Four species of Scotophilus are now known to occur on Madagascar of which three are endemic.
The results of small mammal inventories at 11 sites ranging from sea level to 1000 m a.s.l. on the Masoala Peninsula in northeastern Madagascar are presented. The Rodentia and Lipotyphla (ex Insectivora) of this peninsula, that contain extensive areas of lowland rainforest and some montane habitat, were previously poorly known. Fifteen endemic (5 rodents and 10 tenrecs) and 2 introduced species [Rattus rattus (Linnaeus, 1758) andSuncus murinus(Linnaeus, 1766)] were recorded. Species diversity in the lowland forests was reduced as typically found in other lowland sites in the eastern humid forest, while that of the lower montane zone was notably low as compared with other nearby large forested areas to the interior of the peninsula. Several ideas are presented to explain this difference, including the peninsula effect.
Disturbance by tourists of bats in their day roosts represents a potential threat to the conservation of these mammals. We assessed the effect of experimental tourist visits on behavior of the Malagasy endemic Rousettus madagascariensis (Chiroptera: Pteropodidae) in the Ankarana National Park, northern Madagascar. We measured bat behavior, including time activity budgets, under two levels of experimental human visit proximity (far and near) and illumination (low and high). These visits caused an increase in bat flights and an increase in alertness in a frequently-visited colony with faint ambient daylight. The greatest response occurred for human approaches to 5–6 m that directly illuminated the bats and the least response occurred for approaches to 12–14 m that did not directly illuminate the bats. In an infrequently-visited colony with no ambient daylight, visits that remained 12–14 m away and did not illuminate the bats directly caused an increase in alert behavior and a decrease in bat grooming behavior. The difference in response between the colonies suggests that R. madagascariensis may demonstrate an attenuated response to some frequent human visits. Alternatively, colonies roosting with some ambient light may be less sensitive to disturbance from visits, and colonies with previous experience primarily with hunting visits may be more responsive to disturbance. Maintaining a minimum visit distance of 12 m and not illuminating the bats directly, as well as not opening other roost sites to tourism, is likely to help to limit disturbance of R. madagascariensis by tourists at Ankarana.
On the basis of four visits to the Grotte des Chauves-souris (12°57′S, 49°07′E), Parc National d'Ankarana, northern Madagascar, we examine patterns of sexual dimorphism and seasonal differences in body mass of Rousettus madagascariensis, an endemic Malagasy Pteropodidae. Two visits per season were made over the course of two years, dry season (September 2014 and 2015) and rainy season (January 2015 and 2016). Individuals of this species were trapped when exiting the cave after dusk or entering before dawn. Animals were aged, sexed, and then individually marked before being released. In total, 271 adult males and 289 adult females were captured. Although some overlap was found in measurement ranges, males showed significantly larger mean forearm length and body mass than females, including separate analyses of the four different capture periods and in the combined season dataset. For the September 2015 visit, for which a considerable number of adults of both sexes were captured at dusk and dawn, animals entering the cave before dawn were significantly heavier in body mass than those exiting after dusk. When body mass data were pooled within a season, significant differences were found between the rainy and dry seasons in males, as well as females, indicating fluctuating aspects. Further analyses of intra-season and inter-season showed differences in body mass, presumably associated with the availability of fruit resources. Further, the sex ratios of captured individuals were not equal during different capture sessions and inferences are presented on aspects of the breeding biology of this species.
We studied variation in the Body Condition Index (BCI) of a Malagasy frugivorous bat, Rousettus madagascariensis (Pteropodidae), in relation to the abundance of ectoparasite flies, Eucampsipoda madagascarensis (Nycteribiidae). The study site was a cave in northern Madagascar that was visited three times during the dry season (September 2014, 2015, and 2016) and two times during the wet season (January 2015 and 2016). Two measurements were taken from all captured Rousettus to evaluate their BCI: forearm length and body mass. In total, we sampled ectoparasites from 1,030 R. madagascariensis during the five visits. The BCI of sampled bats showed statistical differences when compared by season and segregated by different age and sex classes, with generally the higher mean values during the wet season and lower values during the dry season. In most cases, the abundance of E. madagascarensis for each of the different bat age and sex classes did not differ between seasons. A weak positive relationship was found for most seasonal visits between host BCI and nycteribiid abundance, specifically in adult males, and sub-adult males and females; such a relationship was not observed for neonates. On the basis of a GLM analysis, our results support the hypothesis of a positive relationship between ectoparasite abundance and host BCI. The seasonal variation in host BCI was not related to nycteribiid abundance, but rather some other factor associated with host physical condition, such as the availability of fruit and correlated shifts in body mass.
Recent molecular evidence has shown that the largest genus of the family Hipposideridae, Hipposideros, is paraphyletic with respect to H. commersonii sensu lato and H. vittatus, both belonging to a species complex referred to as the commersonii group. The taxonomic issues at the generic level of certain species of Hipposideros remain unresolved in part related to insufficient material in previous molecular studies. Herein, we expand sampling of the commersonii group and include H. commersonii sensu stricto from its type locality, Madagascar. Our phylogenetic analysis revealed that the commersonii group forms a highly supported monophyletic clade with H. cyclops, which is sister taxa to Aselliscus and Coelops. A combination of phylogenetic and comparative morphological analyses, as well as divergence time estimates, were used to provide compelling evidence to support the placement of the clade containing the commersonii group and that with H. cyclops in two resurrected genera, Macronycteris and Doryrhina, respectively. Divergence time estimates indicated that Macronycteris and Doryrhina diverged 19 mya and separated from Coelops and Aselliscus in the Oligocene, about 31 mya. The commersonii group underwent a rapid radiation as recently as 3 mya likely in response to favourable climatic conditions during the Late Pliocene in Africa. Phylogenetic analysis of Cyt-b could not resolve relationships within this morphologically conserved complex. Further sampling is necessary to fully elucidate the evolutionary history of Doryrhina. Given that cryptic species are widespread among bats, including within the genus Hipposideros, this study highlights the shortcomings of current chiropteran taxonomy to describe hidden diversity.
Recent fieldwork and associated molecular and systematic studies on the bat fauna of the Comoro Archipelago (Grande Comore, Anjouan, Mohéli, and Mayotte) have provided new insights into the locally occurring species, their origins, and evolutionary history. Based on museum specimens, published studies, and our fieldwork, we provide a review of the Chiroptera of this archipelago. The Comoros, composed of in situ formed volcanic islands of recent geological age, occur midway between Madagascar and the African continent, and approximately 300 km of sea separate this island group from these two potential source areas for bat colonization. Ten species are documented in the Comoro Archipelago and the occurrence of one other species remains uncertain. Of these 10 taxa, one was new to science (Miniopterus aelleni) and two were new for the archipelago (Mops leucostigma and Chaerephon leucogaster), and all three of these taxa are shared with Madagascar. The only endemics to the Comoros are the fruit bats Pteropus livingstonii and Rousettus obliviosus, and the vespertilionid Myotis anjouanensis. Certain species occur on all four islands, while others have more limited distributions. Of the species known from the archipelago, five taxa or sister species occur on Madagascar, which appears to be the source of colonization, rather than the African continent. Based on current phylogeographic information, only one taxon, Miniopterus griveaudi, shows a clear pattern of genetic differentiation between different islands in the archipelago. Hence, in most cases a distance of 40–80 km separating the different islands does not form a measurable dispersal barrier to gene flow.
We tested the effects of aspect ratio, wing loading and body size (forearm length) on four estimators of molecular diversity (based on mitochondrial D-loop and cytochrome-b DNA sequences) among eight Afro-Malagasy species of free-tailed (Family Molossidae) bats. As expected based on many previous animal studies conducted at broader taxonomic scales, FST was significantly negatively correlated with wing loading (a good proxy for dispersal ability), even after correcting for phylogeny. However, haplotype diversity, nucleotide diversity and k (the mean number of nucleotide differences between sequences) were not significantly correlated with body size, aspect ratio or wing loading. According to the metabolic rate hypothesis, we expected a significant negative correlation between k and body size. No such significant correlation was obtained, which is attributed to species differences in population size and the timing of past bottlenecks inferred from population demographic data.
The Mauritius flying fox Pteropus niger is distributed on the islands of Mauritius and La Réunion in the western Indian Ocean. Although recent studies have examined the phylogenetics and systematics of this genus, relatively few have assessed the population genetics of species distributed on oceanic islands and no study has focused on the demographics of P. niger. Here, we present mitochondrial DNA sequence data from 39 individuals of P. niger collected from four main colonies distributed throughout Mauritius. Our results indicate that the Mauritian population of P. niger is likely panmictic, with moderate to high levels of gene flow occurring among colonies distributed across the island. Collectively, our sequence data suggest moderate levels of genetic variation within the population. These findings will help to inform ongoing conservation and disease surveillance initiatives.
The pteropodid fruit bat genus Eidolon is comprised of two extant species: E. dupreanum on Madagascar and E. helvum on the African mainland and offshore islands. Recent population genetic studies of E. helvum indicate widespread panmixia across the continent, although island populations off western Africa show genetic structure. Little is known about the genetic connectivity of E. dupreanum or the divergence time between these two sister species. We examine sequence data for one mitochondrial (cyt-b) and three nuclear regions (β-fib, RAG1, and RAG2) to assess population genetic structure within E. dupreanum and divergence between the two Eidolon spp. In addition, we characterize the demographic history of both taxa using coalescent-based methods. We find little evidence for population structure within E. dupreanum, and suggest that this reflects dispersal based on seasonal fruit availability and a preference for roosting sites in exposed rock outcrops. However, despite apparent panmixia in both Eidolon spp. and large dispersal distances reported in previous studies for E. helvum, these two taxa diverged in the mid-to-late Miocene. Both species are also characterized by population expansion and young, Pleistocene clade ages, although slower population growth in E. dupreanum is likely explained by its divergence via colonization from the mainland. Finally, we discuss the implications of population connectivity in E. dupreanum in the context of its potential role as a reservoir host for pathogens capable of infecting humans.
We present phylogenetic information based on nuclear Rag2 and mitochondrial cytochrome b sequence data for six genera of Molossidae (Chaerephon, Mops, Mormopterus, Otomops, Sauromys, Tadarida) and 18 species, primarily from Africa and the Malagasy region (Madagascar and neighbouring islands), and further include sequences of 12 New World and African taxa sourced from GenBank. There is strong support for the monophyly of the Molossidae included in this study. The Malagasy region taxa Mormopterus jugularis and M. francoismoutoui are supported as a basal clade with an age of≈ 31.2 MYR, and are not monophyletic with the South American M. kalinowskii. Asian Otomops wroughtoni and O. formosus and Afro-Malagasy O. martiensseni and O. madagascariensis form a strongly-supported ≈19.8 MYR-old clade, whose broader relationships among Molossidae are not clearly defined. There is strong support for a ≈ 17.2 MYR-old combined Chaerephon/Mops clade, in which members of these genera show some paraphyly. The monophyly of the genus Tadarida, represented in our analyses by T. brasiliensis from the New World and T.fulminans, T. aegyptiaca and T. teniotis from the Old World, is not upheld, although there is good support for a geographicallydisjunct ≈ 9.8 MYR-old grouping which includes C. jobimena (Madagascar), T. aegyptiaca (Africa) and T. brasiliensis (America). Sauromys is maintained as a monotypic genus, although there is moderate support for its association with T. fulminans and the Chaerephon!Mops clade, the latter of which comprises M. midas, M. leucostigma, M. condylurus, M. bakarii, C. pumilus, C. pusillus, C. leucogaster and C. atsinanana. An ≈ 8.4 MYR-old New World clade comprising representatives of Eumops, Nyctinomops and Molossus was well-supported.
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