Daniel Rakotondravony

The distribution and conservation of bats in the dry regions of Madagascar

We carried out extensive field surveys in the dry forest portions of Madagascar to document the species of bats occurring in these regions. These data combined with information in the literature and museum specimen records indicate that 28 species of Chiroptera occur in this region of the island, of which we documented 27 during our inventories. The community composition at sites occurring in areas of water-eroded sedimentary rock is notably different from sites on alluvial substrates. In contrast to the majority of native land mammal species on Madagascar, much of the microchiropteran fauna is not dependent on large tracts of intact forest and anthropogenic perturbations of forests may have less direct impact on their long-term survival. Conservation strategies for Chiroptera in the dry regions of the island should focus on reducing various types of human disturbance of cave environments.

Sensory Basis of Food Detection in Wild Microcebus murinus

Very little is known about how nocturnal primates find their food. Here we studied the sensory basis of food perception in wild-caught gray mouse lemurs (Microcebus murinus) in Madagascar. Mouse lemurs feed primarily on fruit and arthropods. We established a set of behavioral experiments to assess food detection in wild-born, field-experienced mouse lemurs in short-term captivity. Specifically, we investigated whether they use visual, auditory, and motion cues to find and to localize prey arthropods and further whether olfactory cues are sufficient for finding fruit. Visual cues from motionless arthropod dummies were not sufficient to allow reliable detection of prey in choice experiments, nor did they trigger prey capture behavior when presented on the feeding platform. In contrast, visual motion cues from moving prey dummies attracted their attention. Behavioral observations and experiments with live and recorded insect rustling sounds indicated that the lemurs make use of prey-generated acoustic cues for foraging. Both visual motion cues and acoustic prey stimuli on their own were sufficient to trigger approach and capture behavior in the mouse lemurs. For the detection of fruit, choice experiments showed that olfactory information was sufficient for mouse lemurs to find a piece of banana. Our study provides the first experimental data on the sensory ecology of food detection in mouse lemurs. Further research is necessary to address the role of sensory ecology for food selection and possibly for niche differentiation between sympatric Microcebus species.

Habitat use, roost selection and conservation of bats in Tsingy de Bemaraha National Park, Madagascar

Although the land mammals of Madagascar have been the subject of many studies, the island’s bats have yet to feature prominently on the research or conservation agenda. In this study we used mist nets, acoustic sampling and cave surveys to assess habitat use, seasonality and roost selection. Four microchiropteran species (Triaenops rufus, T. furculus, Miniopterus manavi and Myotis goudoti) appeared to be strongly associated with the forest interior based on trapping, but analysis of time-expanded echolocation recordings revealed that T. rufus and M.␣manavi were frequently recorded in forest edges and clearings. Bat activity was significantly lower inside the forest than at the interface between agricultural land and forest. The caves visited most often by tourists were low in bat abundance and species richness. Anjohikinakina Cave, which was visited infrequently by people, was used by five species and contained between 54% (winter) and 99% (summer) of bats counted in 16 caves and is a site of national importance for bat conservation. Hipposideros commersoni was only netted in our study area during October and may be a migrant to the site or present but inactive during the austral winter. The forest surrounding the caves is therefore important because it provides cover for emerging bats and a potential source of invertebrate prey whilst the forest edge is important to foraging bats.

Two New Species of Mouse Lemurs (Cheirogaleidae: Microcebus) from Eastern Madagascar

The number of newly discovered Malagasy vertebrate taxa has multiplied in recent years, emphasizing the importance of complete taxon sampling for phylogenetics, biogeography, functional ecology, and conservation biology, especially in such a biodiversity hotspot. In particular, the diversity of extant lemurs is much higher than previously thought, and we have yet to comprehend fully the full extent of lemuriform biodiversity. A recent genetic analysis of mtDNA and nDNA sequence data in Malagasy mouse lemurs revealed the existence of several novel mtDNA clades based on new field sampling. These geographically defined and previously unrecognized mtDNA clades corresponded precisely to patterns of population structure revealed in the analysis of the nDNA data, thus confirming their evolutionary divergence from other mouse lemur clades. Two of these independently evolving lineages correspond to specimens that were collected by us in the Marolambo and Manantantely/Ivorona regions. Here we summarize the genetic evidence and report on the morphometric and external characteristics of these animals, formally describing them as new species. This report thus brings the number of currently recognized and described mouse lemur species to 20. The forests in which these mouse lemurs were discovered have been heavily degraded in the past decade, prompting the classification of one of the new species as Endangered by the IUCN, even before its formal description. As with several other newly described lemur species, immediate field studies and appropriate conservation actions are therefore urgent.

Biogeography of Dwarf Lemurs: Genetic Evidence for Unexpected Patterns in Southeastern Madagascar

Seven species of dwarf lemurs (Cheirogaleus spp.) are currently recognized after a recent revision of the genus. During a field study in southeastern Madagascar, we observed 3 distinct morphotypes of Cheirogaleus resembling Cheirogaleus medius, C. major and C. crossleyi. In particular, for Cheirogaleus crossleyi southeastern Madagascar was far away from the known distribution range of the species when referring to the recent revision of the genus. In order to clarify the taxonomic status of the 3 morphotypes, we compared field samples from southeastern Madagascar to museum specimens from several locations in Madagascar and to field samples from Kirindy/CFPF, western Madagascar by genetic analyses using the mitochondrial cytochrome b gene. Genetic data yield strong support for 2 of the 3 morphotypes to represent Cheirogaleus medius and C. major. The third morphotype is genetically closely related to Cheirogaleus crossleyi, albeit more distantly than the other 2 morphotypes to the respective reference samples. The genetic distance is related to a considerable geographic distance between the location of our field study and the origin of the respective reference specimen, because Cheirogaleus crossleyi had been reported only from northern Madagascar. Our field observations indicate an isolated population in southeastern Madagascar. We propose to identify them as Cheirogaleus crossleyi and discuss the population genetic and biogeographic considerations supporting this conclusion.

Predation on Hapalemur griseus griseus by Boa manditra (Boidae) in the Littoral Forest of Eastern Madagascar

Over the past decade it has become abundantly clear that levels of predation on lemurs are much higher than previously surmised. These predators vary from large carnivores (Cryptoprocta ferox) that prey on large diurnal and medium-sized nocturnal primates [1–3], smaller diurnal carnivores (e.g. Galidia elegans) that take nocturnal primates from day nests [4, 5], and diurnal birds of prey (e.g. Polyboroides radiatus, Buteo brachypterus, Accipiter henstii) that feed on both nocturnal and diurnal lemurs [4, 6, 7] to nocturnal owls (e.g. Tyto alba, T. soumagnei, Asio madagascariensis) that feed on small to medium-sized nocturnal primates [8, 9]. In addition, snakes, particularly boa constrictors, have been reported to feed on Malagasy prosimians [4, 5], although well documented acts of predation are few. Herein we report an incident of snake predation on the gentle bamboo lemur (Hapalemur griseus griseus).

Protected area surface extension in Madagascar: Do endemism and threatened species remain useful criteria for site selection?

The ‘hotspot approach’ considers that endemism and threatened species are key factors in protected area designation. Three wetland and forest sites have been proposed to be included into Madagascar’s system of protected areas (SAPM – Systeme des Aires Protegees de Madagascar). These sites are Manambolomaty (14,701 ha) and Mandrozo (15,145 ha) in the west and Bemanevika (37,041 ha) in the north. Biodiversity inventories of these three sites recorded 243 endemic species comprised of 44 reptiles, 54 amphibians, 104 birds, 23 small mammals, 17 lemurs and one fish. Of these 243 species, 30 are threatened taxa comprising two Critically Endangered (CR), 11 Endangered (EN) and 17 Vulnerable (VU) species. The long term ecological viability of these sites has been shown by population stability of the two Critically Endangered flagship species, the Madagascar fish eagle (Haliaeetus vociferoides) in Manambolomaty and Mandrozo and the recently rediscovered Madagascar pochard (Aythya innotata) in Bemanevika. Other threatened species and high biological diversity also justifies their inclusion into Madagascar’s SAPM.

A new species of rodent from the montane forest of central eastern Madagascar (Muridae: Nesomyinae: Voalavo)

ABSTRACT A new species of rodent, Voalavo antsahabensis, from the eastern montane forest of Madagascar, is described from material obtained in the Anjozorobe region of the Central Highlands. The genus Voalavo was previously only known from the mountains of Anjanaharibe-Sud and Marojejy in the Northern Highlands. Several morphological, cranial, and dental characters separate V. antsahabensis from the only other named species in the genus, V. gymnocaudus. The recent discovery of this new taxon, after many years of survey work in the Anjozorobe Forest, has important implications for interpreting estimates of small mammal species richness and biogeographic patterns based on rapid inventories.

Roost site characteristics of sympatric dwarf chameleons (genus Brookesia ) from western Madagascar

Madagascars Brookesia dwarf chameleons are believed to require relatively intact forest for survival. Although they have featured in herpetological surveys, taxonomic reviews and trade assessments, very little is known about their microhabitat requirements or ecology. Over a 5 night period in a deciduous forest in western Madagascar we recorded the night roosting sites for three sympatric Brookesia species. We calculated the area and distance between successive night roost locations and described the characteristics of each roost. Distance between roosts and the area used were larger for B. brygooi and B. perarmata than B. exarmata. The distance between roosts was significantly greater for male than female B. brygooi and B. perarmata . Roost sites were generally in low vegetation ( 0.75 m) with the animals located on stems or leaves. Roost height differed significantly between the species, with B. brygooi using the highest perches and B. exarmata the lowest.

Identifying important areas for the conservation of dwarf chameleons ( Brookesia spp.) in Tsingy de Bemaraha National Park, western Madagascar

Many of Madagascars endemic chameleon spe- cies have restricted ranges and require relatively intact forest for survival but information on their response to habitat degradation is generally lacking, especially in western deciduous forests. We assessed the abundance and density of endemic chameleons from nocturnal sur- veys of roosting animals in Parc National Tsingy de Bemaraha in western Madagascar. We found 444 Brookesia brygooi, 192 B. perarmata ,9 8B. exarmata ,2 2Furcifer nicosiai and two F. cf. petteri. The highest pooled density was for B. brygooi (53.2 ha -1 ), followed by B. perarmata (29.2 ha -1 ) and B. exarmata (18.7 ha -1 ). B. brygooi was ubiquitous, with the highest density and abundance in the disturbed Ankazomanga forest outside the Park, where the similarly sized B. perarmata was absent. B. perarmata, a species endemic to the Park, was abundant in three of the five survey sites, especially where there was a well- developed leaf litter and understorey. B. exarmata, a species endemic to the Bemaraha plateau, was associated with an open understorey and small protrusions of limestone karst. Spatial variation in the density of B. perarmata is an important consideration when interpreting monitoring data and this species is a conservation priority because of its restricted distribution and apparent sensitivity to forest degradation.