Activity patterns and abundance of microchiropteran bats at a cave roost in south‐west Madagascar

Olsson, Annette; Emmett, David; Henson, David W.; Fanning, Eibleis

doi:10.1111/j.1365-2028.2006.00661.x

Cited by 8 publications

(3 citation statements)

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“…The true effective size for T. persicus is probably much larger, given the wider distribution of this species and the fact that our sample includes only a single population. The compatibility of estimated parameters, such as migration and effective population sizes, with estimates from field-based research (Olsson et al, 2006;Steven M. Goodman, 2007, personal observation) lends confidence to this coalescent approach. (In addition, see validation by simulations in later sections.)…”

Section: Evaluation Of Dispersal Hypothesesmentioning

confidence: 97%

ORIGINAL ARTICLE: Coalescent analyses support multiple mainland‐to‐island dispersals in the evolution of Malagasy Triaenops bats (Chiroptera: Hipposideridae)

Russell

Cox

2008

Journal of Biogeography

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Biogeographical questions are increasingly amenable to molecular data and associated methods for demographic inference. Traditionally, genetic analyses have relied heavily on phylogenetic approaches. Dated phylogenies can provide working hypotheses for organismal relationships, including the ability to place them within a spatial and temporal framework. This method also has relevance to biogeography; for instance, comparisons of species cladograms and geographical distributions often allow competing dispersal and vicariance hypotheses to be distinguished ABSTRACT Aim We investigate the directionality of mainland-to-island dispersals, focusing on a case study of an African-Malagasy bat genus, Triaenops (Hipposideridae). Taxa include T. persicus from east Africa and three Triaenops species from Madagascar (T. auritus, T. furculus, and T. rufus). The evolution of this bat family considerably post-dated the tectonic division of Madagascar from Africa, excluding vicariance as a viable hypothesis. Therefore, we consider three biogeographical scenarios to explain these species' current ranges: (A) a single dispersal from Africa to Madagascar with subsequent speciation of the Malagasy species; (B) multiple, unidirectional dispersals from Africa to Madagascar resulting in multiple, independent Malagasy lineages; or (C) early dispersal of a proto-species from Africa to Madagascar, with later back-dispersal of a descendant Malagasy taxon to Africa.Location East Africa, Madagascar, and the Mozambique Channel.Methods We compare the utility of phylogenetic and coalescent methodologies to address the question of directionality in a mainland-to-island dispersal event for recently diverged taxa. We also emphasize the application of biologically explicit demographic systems, such as the non-equilibrium isolation-withmigration model. Here, these methods are applied to a four-species haploid genetic data set, with simulation analyses being applied to validate this approach.Results Coalescent simulations favour scenario B: multiple, unidirectional dispersals from Africa to Madagascar resulting in multiple, independent Malagasy bat lineages. From coalescent dating, we estimate that the genus Triaenops was still a single taxon approximately 2.25 Ma. The most recent Africa to Madagascar dispersal occurred much more recently (c. 660 ka), and led to the formation of the extant Malagasy species, T. rufus.Main conclusions Haploid genetic data from four species of Triaenops are statistically most consistent with multiple, unidirectional dispersals from mainland Africa to Madagascar during the late Pleistocene.

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Section: Evaluation Of Dispersal Hypothesesmentioning

confidence: 97%

ORIGINAL ARTICLE: Coalescent analyses support multiple mainland‐to‐island dispersals in the evolution of Malagasy Triaenops bats (Chiroptera: Hipposideridae)

Russell

Cox

2008

Journal of Biogeography

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“…Andriafidison et al 2006;Andrianaivoarivelo et al 2011;Vololona et al 2020). Information on the timing of exit and entrance movements of Malagasy bats are limited to that of Olsson et al (2006) on insectivorous species, specifically of the family Rhinonycteridae, and no information is available on the island's fruit bat fauna. Members of the widespread Old World genus Rousettus Gray, 1821 usually emerge and return to their cave roost sites once a night (Korine et al 1994;Andrianaivoarivelo et al 2011); and the aim of this current study is to determine the time of emergence and return for the endemic Malagasy cave roosting fruit bat, R. madagascariensis Grandidier, 1928.…”

Section: Introductionmentioning

confidence: 99%

Timing of emergence and cave return, and duration of nocturnal activity in an endemic Malagasy fruit bat

Ramanantsalama

2020

Trop Zool

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Bats emerge from their day roost after dusk and different factors can affect the timing of departure, return, and duration of nocturnal activities. This study provides information on the time of emergence and return of an endemic Malagasy fruit bat, Rousettus madagascariensis, in a cave located in the Réserve Spéciale d’Ankarana, northern Madagascar. Individuals were captured in a narrow passage between the roost and cave exit and capture time for each individual was noted. Variation according to sex, age, and body condition, as well as the influence of season, and the sunset and sunrise time were analyzed. During the dry season, individuals started to emerge at 1913 hours and returned to the cave generally by 0505 hours; the duration of time outside the cave during the dry season was higher in adult females (0952 hours) followed by subadult males (0937 hours), sub-adult females (0931 hours), and adult males (0910 hours). During the wet season, individuals exited at 1926 hours and returned at 0351 hours; as in the dry season, adult females spent more time outside the cave (0833 hours), than sub-adult females (0800 hours), and adult males (0752 hours). The period of emergence varied according to the age and sex classes, and time of predawn return associated with the previous nocturnal activity. The period of return was influenced by season, and age and sex classes. Such information is useful to quantify shifts in bat ecology, especially for endemic species with limited distribution or those playing an important role in ecosystem services.

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“…In addition, few studies have estimated population or colony size of bats on the island (e.g. Olsson et al. , 2006; Jenkins et al.…”

Section: Introductionmentioning

confidence: 99%

Hunting, disturbance and roost persistence of bats in caves at Ankarana, northern Madagascar

Ratrimomanarivo

Rembert

2009

African Journal of Ecology

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Surveys and monitoring of 37 caves in and around the Ankarana Special Reserve, northern Madagascar, yielded evidence of hunting of bats and potential disturbance of bats by miners and tourists, and colony counts for several bat species of potential conservation concern. Colony size decreased by 95% and 14% for a colony of Hipposideros commersoni and a colony of Eidolon dupreanum, respectively, when recent evidence of hunting occurred at those colonies and those declines are probably attributable to hunting. Evidence of hunting occurred commonly at the roosts of those species and most commonly at the roosts of Rousettus madagascariensis. Hunting of pteropodids was associated with high vulnerability of roosts to hunters, little forest buffer between the cave and open savannah and the absence of tombs in the cave. Roost sites of the hunted species persisted for at least several years and this regularity may facilitate hunting. This work supports the ranking of E. dupreanum, R. madagascariensis and H. commersoni as species of conservation concern. Managers should consider the impact of tourist visits on bats and of increasing access to caves for tourism. Conservation efforts for the hunted species should also seek to protect vulnerable and unprotected cave roosts.

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Activity patterns and abundance of microchiropteran bats at a cave roost in south‐west Madagascar

Cited by 8 publications

References 8 publications

ORIGINAL ARTICLE: Coalescent analyses support multiple mainland‐to‐island dispersals in the evolution of Malagasy Triaenops bats (Chiroptera: Hipposideridae)

ORIGINAL ARTICLE: Coalescent analyses support multiple mainland‐to‐island dispersals in the evolution of Malagasy Triaenops bats (Chiroptera: Hipposideridae)

Timing of emergence and cave return, and duration of nocturnal activity in an endemic Malagasy fruit bat

Hunting, disturbance and roost persistence of bats in caves at Ankarana, northern Madagascar

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