Population Density and Home Range Size of <Emphasis Type="Italic">Indri indri</Emphasis> in a Protected Low Altitude Rain Forest

We report the results of a census of Indri indri conducted in Betampona Nature Reserve, a lowland rain forest in eastern Madagascar. In addition, we conducted a year-long study of the ranging behavior of 3 groups in the southwestern region of the reserve. We used 2 methods to calculate population density and home range size, and to provide minimum and maximum estimates. Population density of Indri indri ranged from 6.9–13.2 individuals/km² in Betampona. Mean home range size is 27 ha. The values for population density and home range size are intermediate between values for Indri indri in selectively logged and undisturbed montane rain forest. Our results suggest a relationship between habitat disturbance, population density and home range size for the species. Recent increases in habitat disturbance appear to cause an increase in population density and a decrease in home range size. The results are consistent with ones for other folivorous primate populations. Further research on habitat requirements of Indri and availability in Betampona is necessary to investigate the possibility of translocating Indri from nearby forest fragments into Betampona.     

Deforestation alters the resource base and biomass of endemic stream insects in eastern Madagascar

1. Rainforest streams in eastern Madagascar have species‐rich and diverse endemic insect communities, while streams in deforested areas have relatively depauperate assemblages dominated by collector‐gatherer taxa. We sampled a suite of benthic insects and their food resources in three primary rainforest streams within Ranomafana National Park in eastern Madagascar and three agriculture streams in the park's deforested peripheral zone. We analysed gut contents and combined biomass and stable isotope data to examine stream community responses to deforestation in the region, which is a threatened and globally important hotspot for freshwater biodiversity. 2. Gut analyses showed that most taxa depended largely on amorphous detritus, obtained either from biofilms (collector‐gatherers) or from seston (microfilterers). Despite different resource availability in forest versus agriculture streams, diets of each taxon did not differ between stream types, suggesting inflexible feeding modes. Carbon sources for forest stream insects were difficult to discern using δ¹³C. However, in agriculture streams dependence on terrestrial carbon sources was low relative to algal sources. Most insect taxa with δ¹³C similar to terrestrial carbon sources (e.g. the stonefly Madenemura, the caddisfly Chimarra sp. and Simulium blackflies) were absent or present at lower biomass in agriculture streams relative to forest streams. Conversely, collector‐gatherers (Afroptilum mayflies) relied on algal carbon sources and had much higher biomass in agriculture streams. 3. Our analyses indicate that a few collector‐gatherer species (mostly Ephemeroptera) can take advantage of increased primary production in biofilms and consequently dominate biomass in streams affected by deforestation. In contrast, many forest stream insects (especially those in the orders Plecoptera, Trichoptera and Diptera) depend on terrestrial carbon sources (i.e. seston and leaf litter), are unable to track resource availability and consequently decline in streams draining deforested landscapes. These forest‐specialists are often micro‐endemic and particularly vulnerable to deforestation. 4. The use of consumer biomass data in stable isotope research can help detect population‐level responses to shifts in basal resources caused by anthropogenic change. We also suggest that restoration of vegetated riparian zones in eastern Madagascar and elsewhere could mitigate the deleterious effects of deforestation on sensitive, endemic stream taxa that are dependent on terrestrial carbon sources.     

Reptile, amphibian, and lemur diversity of the Malahelo Forest, a biogeographical transition zone in southeastern Madagascar

Ambatorongorongo Mountain lies at the historical intersection betweenhumid, spiny, and littoral forests in southeastern Madagascar. We report theresults of surveys of the herpetofauna and lemurs occurring in Malahelo Forest,a small (<25 ha) forest fragment lying on the western slope ofAmbatorongorongo Mountain. There are at least 41 reptile, 11 amphibian, and 7lemur species in this forest, including several that are endemic to southeasternMadagascar and are at severe risk of extinction. The species richness of theMalahelo fauna is comparable to that of even the largest forest reserves in theregion. We also evaluate the similarity of the Malahelo herpetofauna to that ofnearby humid, spiny, and littoral forests to assess the biogeographic affinitiesof its amphibians and reptile assemblages. Both groups contain speciescharacteristic of each of the three surrounding forest types, but thebiogeographic patterns appear to differ for amphibians and reptiles. Overall,the herpetofauna and lemurs of the Malahelo Forest indicate that it is a remnantof a biogeographic transition zone between the major forest types ofsoutheastern Madagascar. The combination of high species richness, regionalendemics, and unique herpetofaunal and lemur assemblages should make MalaheloForest a high conservation priority, and we give recommendations for protectingwhat remains of this important transitional forest.     

Modeling co-occurrence between toxic prey and naïve predators in an incipient invasion

Biological invasions can represent important threats to endemic species, including those within the invaders’ food webs. The Asian common toad (Duttaphrynus melanostictus) was introduced to Madagascar in 2011. This introduction presents a potentially dangerous prey item to a relatively naïve, highly diverse endemic carnivore fauna. Using a multivariate niche modeling approach (background test), we assessed the predicted niche overlap between D. melanostictus and six endemic carnivores in eastern Madagascar. The overlap between this potential prey and predators was assessed on four environmental niche axes: temperature, precipitation, vegetation cover and elevation. Our results showed a mixture of niche overlap and divergence between D. melanostictus and the six carnivores for environmental axes tested. There was significant overlap with five of the carnivores on temperature and NDVI axes. On the precipitation axis, there was significant overlap between D. melanostictus with two species. Our results suggested that wide-ranging, locally rare carnivores may overlap extensively with D. melanostictus. The six carnivores that inhabit the eastern rainforest of Madagascar will likely share multiple, niche axes with this novel potential prey item. Species that eat the non-native common toad and are susceptible to its toxins are at conservation risk because their populations may not be robust enough to adapt quickly to this threat. We advocate closely monitoring these emerging interactions and suggest a preemptive conservation strategy for carnivores potentially at risk.     

Integrating field surveys and remote sensing data to study distribution, habitat use and conservation status of the herpetofauna of the Comoro Islands

We studied the non-marine reptile and amphibian species of the volcanic Comoro archipelago in the Western Indian Ocean, a poorly known island herpetofauna comprising numerous microendemic species of potentially high extinction risk and widespread, non-endemic and often invasive taxa. According to our data, the Comoro islands are inhabited by two amphibian species and at least 28 species of reptiles although ongoing genetic studies and unconfirmed historical records suggest an even higher species diversity. 14 of the 28 currently recognized species of terrestrial reptiles (50%) and the two amphibians are endemic to a single island or to the Comoro archipelago. The majority of species are most abundant at low elevation. However, a few endemic species, like the gekkonid lizards Paroedura sanctijohannis and Phelsuma nigristriata, are more common in or even confined to higher altitudes. We created habitat maps from remotely sensed data in combination with detailed species distribution maps produced using comprehensive data from field surveys between 2000 and 2010, literature, and historical locality records based on specimens in zoological collections. Using these data, we assessed the conservation status of the endemic terrestrial reptiles and amphibians according to the IUCN Red List criteria. Our results show that although little area of natural forest remains on the Comoros, many species are abundant in degraded forest or plantations. Competition and predation by invasive species appears to be the most important threat factor for the endemic herpetofauna, together with habitat degradation and destruction, which further favours invasive species. We propose the status Endangered for three species, Vulnerable for one species, Near Threatened for six species, Least Concern for four and Data Deficient for two species. The endemic subspecies Oplurus cuvieri comorensis is proposed for the status Critically Endangered. Based on the results of this study, seven areas of importance for reptile and amphibian conservation on the Comoros are identified. This study shows how remote sensing data can contribute to increasing accuracy and objectiveness of conservation assessments.     

Deforestation and apparent extinctions of endemic forest beetles in Madagascar

Madagascar has lost about half of its forest cover since 1953 with much regional variation, for instance most of the coastal lowland forests have been cleared. We sampled the endemic forest-dwelling Helictopleurini dung beetles across Madagascar during 2002-2006. Our samples include 29 of the 51 previously known species for which locality information is available. The most significant factor explaining apparent extinctions (species not collected by us) is forest loss within the historical range of the focal species, suggesting that deforestation has already caused the extinction, or effective extinction, of a large number of insect species with small geographical ranges, typical for many endemic taxa in Madagascar. Currently, roughly 10% of the original forest cover remains. Species-area considerations suggest that this will allow roughly half of the species to persist. Our results are consistent with this prediction.     

Possible roles of introduced plants for native vertebrate conservation: the case of Madagascar

Restoration approaches rely on native plants; yet in some situations, natural vegetation may not grow fast enough to prevent the fragmentation of original vegetation and the consequent negative impacts on fauna. In this context, some introduced plants may grow faster and provide more food than native species, and they may also contribute to human livelihood. We investigate to what extent introduced plant species (1) can serve as habitat and food for endemic vertebrates and (2) provide benefits to local people. We address this question in Madagascar, characterized by high degrees of endemism, long histories of coevolution between endemic species, highly fragmented forests, and a high reliance of the rural population on natural resources. A literature search for interactions between endemic fauna and introduced flora revealed that 100 of 1,379 introduced species recorded for Madagascar are used by endemic vertebrates. They provide food mainly for primates, flying foxes, and birds, and habitat for all terrestrial vertebrate groups. One hundred vertebrate species were reported to use introduced plants, many of which are fast growing and are useful for populations. Although these introduced plants should be approached with caution due to their potentially invasive behavior, many introduced plants can provide services for the native fauna and for humans. For example, trees can provide an interim solution to secure the survival of endemic fauna that otherwise would be lost due to fragmentation effects. These plants could bridge the time lag until native forest regeneration or restoration with native trees will have become effective.     

Diet and feeding behaviour of the black-and-white ruffed lemur (Varecia variegata variegata) in the Betampona Reserve, eastern Madagascar

The feeding behaviour and diet of the black-and-white ruffed lemur (Varecia variegata variegata) was investigated in the Betampona Reserve, eastern Madagascar. The highly frugivorous diet of this subspecies was confirmed - feeding on fruits accounting for 92.0% of feeding records. Most feeding at Betampona was observed at 10-25 m above the forest floor amongst flexible, small (0.5-5.0 cm diameter) and oblique/horizontal (0-45 degrees ) supports. The Varecia spent on average 21.7% (+/- 1.5) of their daily activity budget feeding and employ a variety of postures that enable them to harvest fruits in the rain forest canopy. The suspensory postures were the most important in allowing Varecia to compete with other smaller-bodied frugivores.     

Rodent endemism,turnover and biogeographical transitions on elevation gradients in the northwestern Argentinian Andes

The aim of this research is to relate patterns of endemism and turnover along a local elevation gradient in northwest Argentina with continental biogeographical transitions. Specimen based records constituted the principal source of information to infer rodent distribution along the elevation gradient. I assessed elevational variation of richness, endemism and turnover by means of non-linear regression analysis. Then I identified five distributional patterns based on the overlap of species geographic range. Their frequency along elevation was used to validate biogeographical boundaries inferred by turnover rates. Eleven species out of 37 (30%) are endemic to the study area. Species richness and endemism were hump-shaped. The rate of endemism reached its maximum value at the upper limit of the forest (2500 m). By contrast, species turnover was U-shaped, with a small peak at 1500 m and a maximum at 3500 m. The species’ geographic range patterns were not randomly distributed along elevation but agglomerated at specific elevation. Species turnover and chorological analysis suggest two biogeographical boundaries, a weaker at 1500 m and a stronger at 3500 m. The 1500 m boundary marks the transition from assemblages dominated by Lowland-widespread fauna at lower elevation to Montane (Andean eastern slopes) species at middle elevation. This boundary is characterized by moderate species turnover and high species richness. The strong turnover rate at 3500 and the dominance of highland Andean and Andean-Patagonian species above this elevation suggest the occurrence of the transition between the Neotropical and Andean regions; which is characterised by an almost complete species replacement.     

The biogeography of Miniopterus bats (Chiroptera: Miniopteridae) from the Comoro Archipelago inferred from mitochondrial DNA

The endemic fauna of the Comoro Archipelago is composed of a mixture of taxa originating from Africa and Madagascar. Bats are the only native land dwelling mammals on this archipelago, but the biogeographical origins for the vast majority of species within this group are ambiguous. We report here genetic analyses based on two mitochondrial DNA markers to infer the origin of Comorian bats belonging to a reputed species complex of Miniopterus that is further distributed across Africa and Madagascar. Phylogenetic reconstructions show that east African M. minor are not closely related to the insular Miniopterus of Madagascar and the Comoros (Grande Comore and Anjouan). The latter cluster into two distinct, monophyletic clades (Clade 1 and Clade 2). Representatives of these clades occur sympatrically both on the Comoros and on Madagascar, and are distinguished by a large genetic distance (K2P: 9.9% for cytochrome b). No haplotypes are shared between any islands, suggesting the absence of contemporary gene flow. Populations of the widespread Clade 1 are furthermore characterized by a significant inter‐island structure (Φ_CT = 0.249), and by high haplotype and nucleotide diversities (h = 0.90–0.98, π = 0.04–0.06). Demographic analyses of Clade 1 suggest secondary contact between two distinct phylogroups (Subclade 1 A and 1B) that reached Grande Comore and Anjouan, and a large, stable population with a long evolutionary history on Madagascar. These results and the current distribution of related lineages suggest that the Comoros were colonized independently at least two or three times by ancestors from Madagascar.     

Integrative taxonomy and phylogeny of leafless Vanilla orchids from the South-West Indian Ocean region reveal two new Malagasy species

The leafless Vanilla species complex from the South-West Indian Ocean (SWIO) region has long been a taxonomic challenge, due to limited patterns of morphological differentiation and an absence of variation within chloroplast sequences. This complex includes seven known morphospecies: V. madagascariensis, V. bosseri, V. decaryana, and V. perrieri endemic to Madagascar, V. humblotii presumed as endemic to the Comoros Archipelago, but also present in Madagascar, V. roscheri from the East African coast, and V. phalaenopsis endemic to Seychelles. A previous population genetic study using microsatellite markers allowed us to distinguish, in addition to the five recognized Malagasy taxa, two other genetic clusters present in the East of the island. An integrative taxonomy approach was therefore conducted by combining microsatellite and morphological data used in the previous study with new data sets, and by adding ITS sequencing data, to validate the taxonomic level of these Malagasy genetic clusters and unravel phylogenetic relationships between SWIO species. As a result, based on phylogenetic, genotypic and morphological evidence, nine species were discriminated in the SWIO region, including seven in Madagascar, with two new eastern species. The leafless Vanilla group originated and diversified in Madagascar, from an ancestor of African descent, with three subsequent independent colonization events from Madagascar to the other territories of SWIO within the two main lineages (white versus yellow flower species). The new Malagasy species, V. allorgeae Andriamihaja & Pailler sp. nov., and V. atsinananensis Andriamihaja & Pailler sp. nov., are described and a new identification key is proposed.     

Diet and feeding behaviour of Indri indri in a low-altitude rain forest

The diet and feeding behaviour of Indri indri were investigated in the Betampona Reserve, eastern Madagascar, over 12 months from February 2000 to February 2001. The highly folivorous diet of this species was confirmed--feeding on foliage (leaves and petioles) accounting for 82% of feeding records. Immature leaves were the preferred dietary item, but at times of relative scarcity mature leaves, fruit, seeds, flowers and bark were substituted. The indri were observed to feed on parts from 22 plant families, 37 genera and at least 42 species. The most important plant families in the diet of Indri were Lauraceae, Clusiaceae and Myristicaceae. Most feeding at Betampona was observed at 5-20 m above the forest floor amongst small (2.1-5.0 cm), oblique/horizontal supports (0-45 degrees). The indri spent 41.4% of their active period feeding most commonly in above-branch postures. Studies such as this are important for the development of conservation management plans for this endangered species.     

A new genus and species of passerine from the eastern rain forest of Madagascar

Cryptosylvicola randrianasoloi is described as a new genus and species in the family Sylviidae. This bird is endemic to the rain forests of eastern Madagascar, where it is restricted to elevations between 900 and 2100 m a.s.l. Cryptosylvicola randrianasoloi is distinguished from other Malagasy, African and Asian taxa by plumage colouration, external morphological characters and voice. The discovery of this new taxon in several well-known areas of Madagascar, and the fact that it has a relatively broad distribution in that country, indicates that much still remains to be learned about the biota of the island.     

Phylogeography of the poison frog Mantella viridis (Amphibia: Mantellidae) reveals chromatic and genetic differentiation across ecotones in northern Madagascar

Mantella viridis is a threatened poison frog species endemic to the ecologically very heterogeneous northern region of Madagascar. The existence of several colour morphs within M. viridis and its very low genetic differentiation to the allopatrically distributed Mantella ebenaui raise questions about the processes driving the differentiation between these poison frog populations and about their taxonomic status. Using a DNA fragment of 476 nucleotides of the mitochondrial cytochrome b gene from 240 individuals of this species complex, we investigated the genetic variability of all known colour morphs of M. viridis, sampling this species throughout its known range, as well as several populations of M. ebenaui. Our genetic results confirm that M. viridis and M. ebenaui are closely related but reveal that no haplotype sharing occurs between these two taxa. Further, our molecular analyses provided evidence for barriers to gene flow among some of the colour morphs. Estimates of overlap of bioclimatic envelopes as assessed by ecological niche modelling also suggest a distinct bioclimatic niche of some of the lineages studied.     

An endemic radiation of Malagasy songbirds is revealed by mitochondrial DNA sequence data

The bird fauna of Madagascar includes a high proportion of endemic species, particularly among passerine birds (Aves: Passeriformes). The endemic genera of Malagasy songbirds are not allied obviously with any African or Asiatic taxa, and their affinities have been debated since the birds first were described. We used mitochondrial sequence data to estimate the relationships of 13 species of endemic Malagasy songbirds, 17 additional songbird species, and one species of suboscine passerine. In our optimal trees, nine of the 13 Malagasy species form a clade. although these birds currently are classified in three different families. In all optimal trees, the sister to this endemic clade is a group of Old World warblers including both African and Malagasy birds. The endemic Malagasy songbird clade rivals other island radiations, including the vangas of Madagascar and the finches of the Galapagos, in ecological diversity.     

Conservation priorities for forest-floor invertebrates of the southeastern half of Madagascar: evidence from two land-snail clades

Leaf litter and soil of tropical forests harbour some of Earth's most diverse, most endangered, yet least understood biological communities. How well do east-southeast Madagascar's reserves protect this resource? A preliminary answer is provided by the landsnail genera Cyclophoridae Boucardicus and Charopidae n. gen., as represented by 3680 specimens in 64 species, collected 1990–1993 from 129 stations in 26 transects, with nine reserves included. These two genera qualify as indicator/target taxa because they are endemic, species-rich, well-defined clades, sensitive to environmental degradation, with species readily identifiable by shells alone. Indices of diversity and endemism were used to rank 12 bioclimate-latitude regions by priority for conservation/collection. The higher-priority regions generally have some forest nominally conserved, of which the lowland-rainforest reserves of Manombo, Kianjavato, and Betampona are especially rich. A crucial exception, however, is the highest-priority region: the coastal-montane rainforests to the north of Tolagnaro (Fort Dauphin), which are completely unprotected and are rapidly being destroyed. (Andohahela Reserve hes westward, where diversity and endemism are 60% and 20% lower, respectively, so it conserves less than a fourth of the general region's endemic diversity.)     

Characterization of 26 microsatellite marker loci in the fossa (Cryptoprocta ferox)

The fossa (Cryptoprocta ferox) is one of eight carnivore species endemic to Madagascar. This species lives in the forests of Madagascar and is classified as vulnerable by the IUCN due to the loss and fragmentation of its natural habitat and the hunting pressure of local people. Twenty-six nuclear microsatellite loci were isolated from genomic DNA derived from a free-ranging fossa from Betampona, Madagascar. Population genetic parameters were estimated on 28 individuals from nine European zoos establishing a baseline to study the genetic health and diversity of captive fossas to support the European Breeding and Conservation Program (EEP). The marker suite averaged 4.4 alleles per locus with an average polymorphic information content of 0.478.     

The rheophilic fauna and invertebrate communities of the tundra zone: A case study of the Southern Yamal

The invertebrate fauna of rivers and streams of the Southern Yamal has been studied using original specimens (122 bottom and vegetation samples). A total of 158 taxa have been recorded, many of which are new for this region. Among them, 18 types of rheophilic macrobenthic communities have been distinguished which mainly correspond to certain types of habitats and watercourses. A depletion in the set of rheophilic communities (including the loss of almost all crenal and many phytal ones), the taxonomic structure of communities (the loss of large bivalves and most gastropods, hemipterans, and dragonflies), and the total species composition of the fauna, as well as changes in the balance of life forms towards filter feeders (larvae of the family Simuliidae midges and pea clams) and leveling of the differences between the communities of large and small watercourses when compared with the communities of the Russian forest zone, have been recorded. Widespread Eurosiberian species are the most abundant in the rheophilic fauna of the examined region, Arctic species account for ∼20% of all species, and six East Siberian species have been found. No endemic species have been discovered.     

Does elevation influence mayfly emergence timing? A case study using New Zealand's endemic ephemeropteran fauna

1. The timing of adult emergence in stream insects is tightly constrained by environmental cues. Emergence is therefore predicted to be delayed at higher elevations, although few studies have empirically demonstrated this phenomenon. 2. We analysed the collection records of New Zealand's entire endemic mayfly fauna (52 species, 20 genera, 8 families) to test for correlations between adult emergence timing and elevation. 3. Significant positive associations between emergence timing and elevation were detected in more than half (11/21) of the taxa included in detailed analyses, with emergence delays for individual taxa (mean 3.2 ± 2.6 days per 100 m) similar to those previously observed in other freshwater insect taxa. Interspecific analyses accounting for phylogenetic relatedness revealed a non-significant positive relationship (P = 0.14) between median elevation and median collection date. 4. While elevation often has significant effects on insect emergence, these results also emphasise the idiosyncratic responses of individual insect taxa to environmental conditions. More detailed temporal studies are crucial for assessing the ongoing impacts of climate-driven shifts on insect phenology.