Northwestern Madagascar Research Articles

A preliminary population viability analysis of the critically endangered blue-eyed black lemur (Eulemur flavifrons)

Population viability analysis is an important tool to assess the extinction risk in small populations of highly specialized primates. The blue-eyed black lemur (Eulemur flavifrons) is critically endangered with a restricted range in the north-western dry deciduous forest of Madagascar, where habitat fragmentation and loss of forest connectivity threaten its survival. We performed a population viability analysis (PVA) of this lemur in Ankarafa Forest in the Sahamalaza Peninsula National Park, north-western Madagascar, to determine the demographic parameters most influential for population persistence and to assess extinction probabilities. We conducted PVA analyses using different demographic parameters which characterize the species including reproduction, lifespan and population size using the software VORTEX for six scenarios with 100 iterations and simulated over 100 years. The simulations suggested the first extinction within 13 years when the percentage of habitat destruction increased up to 12%. Severe habitat destruction such as fire and logging was the major cause which led to the risk of population extinction. Conservation strategies, in particular measures to reduce habitat destruction, are proposed to ensure the survival of this critically endangered lemur. Une Analyse de viabilité de population (AVP) est un outil important pour évaluer le risque d'extinction de petites populations de primates très spécialisés. Le lémur aux yeux turquoise (Eulemur flavifrons) est en danger critique d'extinction, avec une aire de répartition qui se limite à une forêt sèche décidue du nord-ouest de Madagascar, où la fragmentation de l'habitat et la perte de connectivité de la forêt menacent sa survie. Nous avons réalisé une AVP de ce lémurien dans la forêt d'Ankarafa, dans le Parc National de la Péninsule de Sahamalaza, au nord-ouest de Madagascar, pour déterminer quels étaient les paramètres démographiques qui avaient le plus d'influence sur le maintien de la population et pour évaluer ses probabilités d'extinction. Nous avons fait des AVP en nous servant de différents paramètres démographiques qui caractérisent cette espèce, comme la reproduction, la durée de vie et la taille de la population, en utilisant le logiciel VORTEX pour six scénarios, avec 100 itérations, simulés sur 100 ans. Les simulations suggéraient la première extinction dans 13 ans, lorsque le pourcentage de destruction de l'habitat passait à 12%. Une grave destruction de l'habitat, par le feu ou les coupes d'arbres, était la cause majeure conduisant au risque d'extinction de la population. Des stratégies de conservation, en particulier des mesures pour réduire la destruction de l'habitat, sont proposées pour assurer la survie de ce lémur en danger critique d'extinction.

Variations in the excretion patterns of helminth eggs in two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in northwestern Madagascar.

Many factors can influence the parasite load of animal hosts, but integrative studies that simultaneously investigate several factors are still rare in many taxonomic groups. This study investigates the influence of host species, host population density, parasite transmission mode, sex, and two temporal (month, year) factors on gastrointestinal parasite prevalence and fecal egg counts of two endemic primate species from Madagascar, Microcebus ravelobensis and Microcebus murinus. A total of 646 fecal samples were available and analyzed from three dry seasons. Six different helminth egg morphotypes were found, and these were Subulura sp. (14.51 % prevalence), strongyle eggs (12.95 %), Ascaris sp. (7.94 %), Lemuricola sp. (0.17 %), and two forms of tapeworms (Hymenolepis spp.) (1.73 and 0.69 %). Coinfection with more than one egg type was observed in 21.22 % of the samples containing eggs. Multivariate analyses revealed that host species and sex did neither explain significant variation in the prevalence and fecal egg counts of parasites with direct life cycles (Ascaris sp., strongyle egg type, Lemuricola sp.) nor of arthropod-transmitted parasites (Subulura sp.). However, fecal egg counts of Subulura sp. differed significantly between study sites, and the prevalence of Subulura sp. and of parasites with direct life cycles was influenced by temporal parameters, mainly by differences between study years and partly between months. When comparing the findings with the yearly and seasonal rainfall patterns in the area, most results are in accordance with the hypothesis of an increased vulnerability of the host toward infection under some sort of environmental challenge.

Leaf phenological patterns of trees, shrubs and lianas in a dry semi-deciduous forest of north-western madagascar: functional types and adaptive significance

Plant phenology was studied in the dry semi-deciduous forest of Badrala (northwestern Madagascar). All categories of litterfall collected bi-weekly in 20 traps from the beginning of one year’s to the end of the next year’s dry season were separated, identified and weighed. The quantitative database on leaf litter production by different tree, shrub and liana species was supplemented by direct bi-weekly observations of their leaf flush, flowering and fruiting. Although distributed along a continuum, leaf-shedding rhythms of 36 species, out of about 90 species identified in leaf litterfall, could be classified into four categories (early deciduous, progressively deciduous, late deciduous, and evergreen) each having significantly different responses to variations of meteorological factors. The adaptation of the phenological responses, the complementary ecological role they played and the possible responses of the forest ecosystem to future climate changes are finally discussed.

Spatio-Temporal Change in Crowned (Propithecus coronatus) and Decken's Sifaka (Propithecus deckenii) Habitat in the Mahavavy-Kinkony Wetland Complex, Madagascar

The crowned sifaka (Propithecus coronatus) and Decken's sifaka (Propithecus deckenii) are Endangered lemurs endemic to west and central Madagascar. Both have suffered habitat loss and fragmentation throughout their ranges. The goal of this study, conducted in the Mahavavy-Kinkony Wetland Complex (MKWC) in northwestern Madagascar, was to assess the effects of historical change in the species' habitats, and to model the potential impact of further land-use change on their habitats. The IDRISI Andes Geographical Information System and image-processing software was used for satellite-image classification, and the Land Change Modeler was used to compare the natural habitat of the species from 1973 to 2005, and to predict available habitat for 2050. We analyzed two forests in the MKWC occupied by P. coronatus (Antsilaiza and Anjohibe), and three forests occupied by P. deckenii (Tsiombikibo, Marofandroboka and Andohaomby). The two forests occupied by P. coronatus contracted during the period 1949-1973, but then expanded to exceed their 1949 area by 28% in 2005. However, the land change model predicted that they will contract again to match their 1949 area by 2050, and will again lose their corridor connection, meaning that the conservation gains for this species in the complex are at risk of being reversed. The three forests occupied by P. deckenii have declined in area steadily since 1949, losing 20% of their original area by 2005, and are predicted to lose a further 15% of their original area by 2050. Both species are therefore at risk of becoming even more threatened if land-use change continues within the complex. Improved conservation of the remaining forest is recommended to avoid further loss, as well as ecological restoration and reforestation to promote connectivity between the forests. A new strategy for controlling agriculture and forest use is required in order to avoid further destruction of the forest.

Social Behavior and Dominance of the Crowned Sifaka(Propithecus coronatus)in Northwestern Madagascar

We carried out a study of the social behavior and dominance hierarchy in three groups of crowned sifaka (Propithecus coronatus) in the Antrema Forest Station in north-west Madagascar. Data were collected from April to June 2009 and October to November 2009 using all-occurrence sampling. During 273 hours of observation, the majority of social behaviors observed were grooming interactions (39%), followed by agonistic behavior (25%), play (19%), scent-marking (9%), call-localization (5%) and approach (3%). A social hierarchy was maintained in the groups of P. coronatus, with females dominating the males. Although dif- ferent groups of P. coronatus defended their territories against other neighboring groups of the same species, the most frequently observed outcome of intergroup encounters was tolerance. In addition, we detected no significant change of sifaka behavior during interspecific encounters with rufous brown lemur ( Eulemur rufus) or with mongoose lemur (Eulemur mongoz), suggesting these two species live in total sympatry with P. coronatus.

Craniofacial Morphology of Vintana Sertichi (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar

ABSTRACTThe Gondwanatheria are an enigmatic clade of Cretaceous and Paleogene mammals known from South America, Africa, Madagascar, India, and the Antarctic Peninsula. The eight valid species—each belonging to a monotypic genus and the first of which was described only 30 years ago—are represented almost exclusively by isolated teeth, in addition to fragmentary dentaries attributed to Sudamerica, Gondwanatherium, Ferugliotherium, and an unnamed taxon from Tanzania. No cranial (skull exclusive of lower jaw) or postcranial material has heretofore been assigned to the Gondwanatheria, a severe limitation that has precluded a comprehensive assessment of phylogenetic affinities. Here we describe, in detail, the first cranial specimen of a gondwanatherian mammal. This material consists of a complete and well-preserved cranium of the sudamericid Vintana sertichi, recovered from the Upper Cretaceous (Maastrichtian) Maevarano Formation in the Mahajanga Basin of northwestern Madagascar. Salient features of the cranium include elongate, scimitar-like jugal flanges, huge orbits, strong klinorhynchy, and a vaulted nuchal region. Micro-computed tomography greatly facilitated the delineation of sutures and the description of internal morphology. The cranial features of Vintana are compared with those of a broad range of synapsids, with particular concentration on other Mesozoic mammaliaforms. The cranium of Vintana exhibits a mosaic of extremely primitive and extremely derived features. It is the second largest known for a Mesozoic mammaliaform, superseded only by that of the eutriconodontan Repenomamus giganticus from the Early Cretaceous of China. Vintana is the largest known Late Cretaceous mammaliaform; it is also the largest known Mesozoic mammaliaform from Gondwana.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

Introduction, Systematic Paleontology, and Geological Context of Vintana Sertichi (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar

ABSTRACT—Vintana sertichi is a sudamericid gondwanatherian mammal known only from the Upper Cretaceous (Maastrichtian) Maevarano Formation in the Mahajanga Basin of northwestern Madagascar. It is based on a single specimen, a well-preserved and virtually complete cranium discovered in 2010 near Lac Kinkony. The cranium is superficially bizarre and constitutes the only cranial remains of the poorly known, phylogenetically enigmatic Gondwanatheria, which are otherwise known only from isolated teeth and fragmentary dentaries. Gondwanatheria are represented by seven other monotypic genera assigned to two families (Ferugliotheriidae and Sudamericidae). Historically, this clade was assigned to Xenarthra, Paratheria (as a sister group to Xenarthra), Multituberculata, Allotheria (as a sister group to Multituberculata), Mammalia incertae sedis, and, most recently, back to Multituberculata or a close relative of Multituberculata. The craniodental evidence provided by Vintana supports inclusion in Sudamericidae, the monophyly of Gondwanatheria, and the position of Gondwanatheria as nested within or sister to Multituberculata. In addition to briefly reviewing the taxonomic composition and phylogenetic history of Gondwanatheria, this introductory chapter sets the stage for the other chapters in the volume by (1) briefly summarizing the inferred life habits of gondwanatherians; (2) reviewing the systematic paleontology of V. sertichi; and (3) providing overviews of the discovery of the holotypic specimen, its preservation, its preparation, and the imaging and measurement techniques used to study it. The chapter closes with an overview of the geological context of V. sertichi, which indicates that the species lived in a coastal floodplain environment and in a highly seasonal, semiarid climate.

Unusual evolution of silica-under- and -oversaturated alkaline rocks in the Cenozoic Ambohimirahavavy Complex (Madagascar): Mineralogical and geochemical evidence

Abstract The almost unknown Ambohimirahavavy ring complex in the Cenozoic alkaline province of northwestern Madagascar has recently attracted considerable interest because of the discovery of important rare-metal mineralization. The complex consists of arc-shaped bodies made up of silica-under- and -oversaturated syenites and extremely evolved peralkaline granitic dykes, as well as several mafic to felsic volcanic units, including basalt, phonolite and trachyte, all of which have an alkaline affinity. Uranium–lead zircon ages of 24.2 ± 0.6 Ma and 23.5 ± 6.8 Ma have been obtained for nepheline syenites and peralkaline granitic dykes, respectively, which, together with field data and ages of neighboring complexes, support emplacement controlled by regional lithospheric structures, rather than an evolving hot spot. Whole-rock major and trace-element and Sr–Nd isotopic data for the mafic suite suggest that the parental melt of this complex was generated by low degrees of melting of a metasomatized mantle source with residual amphibole. Fractional crystallization of this alkali basaltic melt likely produced the silica-undersaturated suite. We propose that the silica-oversaturated suite evolved from the undersaturated melt after contamination of the latter by crustal material. Further evolution to peralkaline compositions in both suites is attributed mainly to plagioclase and alkali feldspar segregation. Nepheline and feldspar compositions, as well as considerations of mineral equilibria among mafic silicates and Fe–Ti oxide minerals indicate crystallization temperatures of 1000 to 700 °C and an oxygen fugacity of 0.4 to 0.8 log units below the fayalite–magnetite–quartz (FMQ) buffer at 1 kbar for the silica-undersaturated melt, and temperatures of 860 to 570 °C and an oxygen fugacity of 1.5 to 3.8 log units below FMQ for the oversaturated syenitic melt. The undersaturated melt evolved towards a more peralkaline composition. Crystallization of arfvedsonite plus aegirine further reduced the melt the evolution of which ended with fluid exsolution. At late stages of crystallization, the oversaturated melt departed from the reducing trend of the undersaturated melt, evolving towards high oxygen fugacity. Very late exsolution of the fluid permitted concentration of the HFSE in the last stages of magmatic evolution with local production of low-temperature pegmatitic phases extremely enriched in these elements.

Natural History of a Madagascan GeckoBlaesodactylus ambonihazoin a Dry Deciduous Forest

Abstract: Several aspects of natural history of Blaesodactylus ambonihazo, a gecko distributed in a dry forest of northwestern Madagascar, were investigated in the rainy and dry seasons between 2000 and 2006. There were no significant sexual size differences in snout-vent length, and no sexual dimorphism was detected either in head width or body mass. Females ceased oogenesis during the rainy season and were recrudescent at the beginning of the dry season. They probably lay eggs in the middle of the dry season. Hatchlings were observed at the beginning of the rainy season and probably reach adult size in the subsequent dry season. At night geckos perched on tree trunks and buildings and exhibited typical sit-and-wait foraging. During the day they retreated to shelters, mainly crevices between buttress roots. The gecko was thermally passive to environmental temperatures, showing a wide range of cloacal temperatures (15–30 C), but they selected relatively higher substrate temperatures at low air temperature...

Miocene benthic foraminifera from Nosy Makamby and Amparafaka, Mahajanga Basin, northwestern Madagascar

Madagascar is well known for its fossil deposits and hosts one of the world’s most important Upper Cretaceous terrestrial faunal sites (in the Mahajanga and Morondava Basins in the west and northwest of the island). Cenozoic marine fossils are also described from Madagascar, but these have received far less attention from the paleontological community, with most of this work dating from the 19th and early 20th centuries. Our study reports a new comprehensive microfossil assemblage from a Miocene sequence on the island of Nosy Makamby. After washing, sieving and sorting (∼30kg), twenty-five genera of foraminifera were identified including Alveolina, Ammodiscus, Ammonia, Archaias, Bolivina, Borelis, Cassidulina, Cyclammina, Cycloforina, Dentalina, Elphidium, Hauerina, Lagena, Lepidocyclina, Nodosaria, Nonion, Nonionella, Peneroplis, Pyrgo, Quinqueloculina, Rhabdammina, Spirillina, Spirolina, Spiroloculina and Triloculina. Ostracods are found in association with the foraminifera, as well as many other macroinvertebrate fossils (including bivalves, gastropods, and echinoids) in addition to vertebrate fossils. Together, the assemblage indicates that during the late Miocene, Nosy Makamby was a tropical, near-shore environment, probably similar to that seen today. Furthermore, the existence of epiphytic foraminiferans (e.g., Elphidium) suggests that sea-grass beds were likely present.

Vahiny depereti, gen. et sp. nov., a new titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous Maevarano Formation, Madagascar

ABSTRACTHere we describe Vahiny depereti, gen. et sp. nov., a new titanosaur dinosaur from the Upper Cretaceous Maevarano Formation of northwestern Madagascar. Vahiny is distinguished from other titanosaurs by characteristics of the basal tubera, basipterygoid processes, parasphenoid, and cranial nerve foramina. Diagnostic cranial material of Vahiny formalizes the long-standing hypothesis that two titanosaur genera were present in the Late Cretaceous of Madagascar. The other titanosaur, Rapetosaurus krausei, is the most common dinosaur in the fauna and is known from hundreds of bones, including multiple partial skeletons and skulls. In contrast, non-Rapetosaurus elements are extremely rare. Of these elements, which have been called ‘Malagasy Taxon B,’ we identify a partial braincase as the holotype of Vahiny depereti. Although Vahiny and Rapetosaurus coexisted on the island of Madagascar, differences in their braincases indicate that they are not closely related to one another. Instead, Vahiny is most similar to Jainosaurus from the Late Cretaceous of India, and shares similarities with the South American taxa Muyelensaurus and Pitekunsaurus.

Abondance du potamochère, Potamochoerus larvatus, dans les savanes du Nord-Ouest de Madagascar et risques épidémiologiques associés

Le potamochère, Potamochoerus larva- tus, est un réservoir sauvage potentiel de maladies enzootiques à Madagascar. Parmi celles-ci, la peste porcine africaine (Ppa) est une des plus inquiétantes. Diag- nostiquée dans ce pays depuis 1998, cette maladie virale majeure d’un point de vue socio-économique est inféodée aux suidés et y est encore aujourd’hui très répandue. La caractérisation des voies de transmission du virus entre pota- mochères et porcs domestiques est une étape préliminaire indispensable à la mise en œuvre d’une prophylaxie sani- taire contre la Ppa. Cette étude a pour objectif de préciser le risque de transmis- sion de la maladie entre potamochères et porcs domestiques dans les savanes périphériques du Parc national de l’Anka- rafantsika, dans le Nord-Ouest de Mada- gascar, où sont présents de nombreux élevages porcins. La méthode des Indices kilométriques d’abondance a permis de mettre en évidence une augmentation significative de l’abondance de ces sui- dés sauvages hors de la forêt durant la période de fructification de Strychnos spi- nosa. Le risque de transmission de la Ppa durant cette période apparaît donc plus élevé dans les sites où sont présents ces arbustes. Sur le plan épidémiologique, la maturité et l’occupation spatiale de S. spinosa peuvent servir d’indicateurs de présence du potamochère dans l’ouest de Madagascar. Son utilisation pour adapter les pratiques d’élevage dans une optique de réduction des contacts pourrait limiter le risque de contamination potentielle par le virus de la Ppa ou d’autres agents pathogènes transmis par les suidés sauvages.

Ecological Variability and Carbon Stock Estimates of Mangrove Ecosystems in Northwestern Madagascar

Mangroves are found throughout the tropics, providing critical ecosystem goods and services to coastal communities and supporting rich biodiversity. Despite their value, world-wide, mangroves are being rapidly degraded and deforested. Madagascar contains approximately 2% of the world’s mangroves, >20% of which has been deforested since 1990 from increased extraction for charcoal and timber and conversion to small to large-scale agriculture and aquaculture. Loss is particularly prominent in the northwestern Ambaro and Ambanja bays. Here, we focus on Ambaro and Ambanja bays, presenting dynamics calculated using United States Geological Survey (USGS) national-level mangrove maps and the first localized satellite imagery derived map of dominant land-cover types. The analysis of USGS data indicated a loss of 7659 ha (23.7%) and a gain of 995 ha (3.1%) from 1990–2010. Contemporary mapping results were 93.4% accurate overall (Kappa 0.9), with producer’s and user’s accuracies ≥85%. Classification results allowed partitioning mangroves in to ecologically meaningful, spectrally distinct strata, wherein field measurements facilitated estimating the first total carbon stocks for mangroves in Madagascar. Estimates suggest that higher stature closed-canopy mangroves have average total vegetation carbon values of 146.8 Mg/ha (±10.2) and soil organic carbon of 446.2 (±36.9), supporting a growing body of studies that mangroves are amongst the most carbon-dense tropical forests.

Two More New Species of Prockiopsis Baill. (Achariaceae) from Madagascar

Abstract Schatz, G. E. & P. P. Lowry II (2013). Two more new species of Prockiopsis Baill. (Achariaceae) from Madagascar. Candollea 68: 277–283. In English, English and French abstracts and keys. Recent gatherings from 2009 made on the Ampasindava peninsula in northwestern Madagascar and to the west of Fort Dauphin reveal two new species of the endemic Malagasy genus Prockiopsis Baill. (Achariaceae). In contrast to the three heretofore known species, all of which possess six petals, one of the new species, Prockiopsis razakamalalae G. E. Schatz, Lowry & Rakotovao, possesses only four petals, whereas the other one, Prockiopsis grandis G. E. Schatz & Lowry, possesses eight (or nine) petals. Both new species are given preliminary conservation assessments of “Critically Endangered”. A key to the five species of Prockiopsis is provided in English and French.

Dietary modification by common brown lemurs (Eulemur fulvus) during seasonal drought conditions in western Madagascar

Primates often modify dietary composition in relation to seasonal changes in food availability or climate conditions. We studied the feeding patterns of a troop of common brown lemurs (Eulemur fulvus), a semi-frugivorous strepsirhine, in a dry forest in northwestern Madagascar. To understand the mechanism of dietary modification, we recorded daily feeding times of diet items during 101 full-day observations over 1 year, and then conducted a linear model analysis to examine the effects of fruiting tree density in the forest, daily ambient temperature, and weekly rainfall (index of water retained in the forest) on the lemurs' daily feeding time. The lemurs spent dramatically more time on leaf-eating as well as total feeding time, and less time on fruit-eating during the late dry season (total 152 min/day, frugivory 56 min/day, folivory 77 min/day), as compared with other seasons when the diet was highly frugivorous (total 96 min/day, frugivory 81 min/day, folivory 8 min/day). Folivory increased as temperatures rose under the condition of low weekly rainfall, whereas frugivory was unrelated to fruiting tree density. Most (97.4%) diurnal folivory during the late dry season was spent consuming Lissochilus rutenbergianus, chewing the succulent leaves and licking the juice. Because the nutritional analysis showed that L. rutenbergianus is rich in water (80.1% of fresh weight) but poor in protein and nonstructural carbohydrates, its increased use was probably for rehydration. We conducted 13 full-night observations, because brown lemurs increase nocturnal activities during the dry season. At nighttime, the lemurs tended to spend more time eating fruit in the late dry season (32 min/night) than in the early dry season (14 min/night), and never consumed L. rutenbergianus. Fruits rich in nonstructural carbohydrates can be energy sources for Eulemur. They likely engaged in additional nocturnal frugivory for energy compensation. Brown lemurs have a flexible strategy of modifying their diet and feeding activities to cope with environmental stresses.

Molecular, morphological and osteological differentiation of a new species of microhylid frog of the genus Stumpffia from northwestern Madagascar.

We describe a new small-sized microhylid frog of the genus Stumpffia and provide a preliminary survey of Stumpffia diversity in northern and northwestern Madagascar based on molecular and morphological data. Analysis of 68 previously published and 142 newly generated DNA sequences of a fragment of the mitochondrial 16S rRNA gene revealed a large genetic diversity within Stumpffia, with numerous strongly differentiated lineages occurring across Madagascar. The anal. ysis confirmed a clade formed exclusively by Stumpffia species occurring in north/northwestern Madagascar and contain. ing almost all species from this area. Based on DNA sequences of the RAG1 gene, we further assess that most of the deep mitochondrial lineages do not share haplotypes in this nuclear marker, even in the few cases of sympatry, which we interpret as confirmation of their status as independent evolutionary lineages. Micro-computed tomography revealed subtle differences in phalangeal formulae among some of these candidate species, providing additional taxonomic characters for future revisions of the genus. The newly described species Stumpffia analamaina sp. nov. occurs 27 km north-west of Antsohihy and is at present the southernmost confirmed Stumpffia of the north/northwestern clade. It is mainly characterized by a snout-vent length of 10-12 mm, advertisement calls consisting of a series of short melodious chirps, manus with four fingers and pes with five toes, with only slight length reduction of first finger and toe. It furthermore does not share haplotypes with any other Stumpffia species in 16S or RAG1, and has relatively longer hands and feet compared with other small-sized Stumpffia of the north/northwestern clade such as S. madagascariensis and S. pygmaea. The new species lives in an area of dry forest where it was found in leaf litter along a small stream bordered by degraded gallery vegetation. Due to the limited distributions of almost all species in the north/northwestern Stumpffia clade, the rareness of appropriate microhabitat around the type locality of S. analamaina sp. nov. and the rampant habitat destruction in this part of Madagascar, we propose a threat status of Critically Endangered for this new species.

A new, richly fossiliferous member comprised of tidal deposits in the Upper Cretaceous Maevarano Formation, northwestern Madagascar

A new member of the Upper Cretaceous (Maastrichtian) Maevarano Formation is proposed to accommodate a distinctive succession of strata exposed along the shores of Lac Kinkony in northwestern Madagascar. The new Lac Kinkony Member overlies fully terrestrial sandstones of the Anembalemba Member of the Maevarano Formation, and is capped by marine dolostones of the Berivotra Formation. In the stratotype section, the base of the Lac Kinkony Member consists of siltstone interbeds that host networks of Ophiomorpha. Siltstone facies pass up-section to distinctive white sandstones packed with dolomitic mud matrix that exhibit rhythmic clay drapes, flaser and wavy bedding, and oppositely-oriented ripples developed on the toes of larger foresets. Thin flat interbeds of microgranular dolostone and claystone comprise the uppermost facies of the Lac Kinkony Member, and a laterally traceable ravinement bed mantled by cobbles of rounded dolostone marks the contact with the superjacent Berivotra Formation. Deposits of the Lac Kinkony Member are interpreted to represent siliciclastic and carbonate tidal flats dissected by tidally-influenced rivers. Vertebrate fossils are abundantly preserved in these coastal deposits, and are locally concentrated in microfossil bonebeds that have the potential to yield thousands of small identifiable specimens. In addition to many taxa already known from the Maevarano Formation, the Lac Kinkony Member has yielded a wealth of phyllodontid albuloid fish skull elements, the distal humerus of a new frog taxon, five vertebrae representing two new snakes, a tooth of a possible dromaeosaurid, and a complete skull of a new mammal. The discovery of several new vertebrate taxa from this new member reflects the fact that it samples a previously unsampled nearshore, peritidal paleoenvironment in the Late Cretaceous of Madagascar.

Social organisation of the northern giant mouse lemur Mirza zaza in Sahamalaza, north western Madagascar, inferred from nest group composition and genetic relatedness

Shelters such as leaf nests, tree holes or vegetation tangles play a crucial role in the life of many nocturnal mammals. While information about characteristics and availability of these resources may help in conservation planning, nest use gives an indication about a species’ social organisation. The northern giant mouse lemur (Mirza zaza) is threatened by habitat loss within its restricted range. Our aim was to examine nest site preferences of M. zaza and to explore the species’ social organisation by examining sleeping site aggregation size and genetic relatedness within and between such aggregations. In the Ankarafa Forest inside Sahamalaza – Iles Radama National Park, northwestern Madagascar, we radio-tagged five male and three female M. zaza and followed them for 2.5 months during the dry season. We identified sleeping trees and observed animals during emergence in the evening and return in the morning. We compared sleeping trees and microhabitats around nest sites to trees and habitat used during nightly activity and to random sites. We found that nests were well covered by canopy, even during the dry season, and were located near the tree trunk a few meters below the tree top. Nest sites were characterised by large (> 30 cm DBH) and tall trees (>16 m) with many lianas. Up to four animals shared one to three group-exclusive nests for up to 50 days. Two of the nest groups included two and three males with fully developed testes. Relatedness data revealed that the adult males sharing nests were either unrelated or closely related. These data suggest that M. zaza is sleeping in social nest groups including multiple males, which is unusual among nocturnal strepsirrhines. Apart from protecting suitable sleeping trees and discouraging selective logging of large trees, we recommend conducting further studies on the species’ social organisation throughout an entire season.

Habitat shifting by the common brown lemur (Eulemur fulvus fulvus): a response to food scarcity

During periods of food scarcity, most primates display behavioral responses, such as dietary switching or adjustment of traveling and foraging efforts, within home ranges. In rare cases, several primate species leave their home ranges for other remote habitats to seek alternative resources; this migration-like behavior is termed "habitat shifting." Reports of habitat shifting have concentrated on platyrrhines, but this behavior has rarely been observed among prosimians. During 1 year of observation of a troop of common brown lemurs (Eulemur fulvus fulvus) in Ankarafantsika National Park, northwestern Madagascar, habitat shifting occurred twice. To understand the causes of this behavior, I examined the seasonal availability of fruit resources in the range continuously used by the troop during the year (defined as the annual range) and compared feeding activities and vegetation types between the annual range and new areas. The troop usually stayed within a 38.7-ha annual range, defined by a 95 % fixed kernel analysis based on GPS location data collected at 5-min intervals. In April 2007, the lemurs suddenly moved to a habitat 1.0-1.5 km south of their annual range and concentrated on the consumption of Grewia triflora fruits for 2 weeks. In November 2007, they visited a habitat 0.8-1.7 km southeast of the annual range and exploited fruits of Landolphia myrtifolia. These new areas were open habitats with high densities of the respective fruit species. The density of fruiting trees was low in the annual range during these periods; thus, habitat shifting to areas with different phenological productivity appeared to be an effective response to fruit scarcity. Brown lemurs are generally categorized as a nonterritorial species, and the lemurs observed here showed no agonistic behavior in intergroup encounters during range shifting. Such nonterritoriality may allow brown lemurs to shift habitats, a behavior resulting in long-term absence from their annual range.

Stable carbon isotope values confirm a recent increase in grasslands in northwestern Madagascar

Madagascar is home to some of the world’s most unique plants and animals. Unfortunately, anthropogenic forest loss has had a dramatic impact on both floral and faunal communities. In many regions the scale and timing of this loss remains poorly constrained. Such is the case for northwestern Madagascar. Pollen records for this region suggest that fires and grass abundance increased around 1000 calendar years before present (cal. BP), as well as c. 500 cal. BP, presumably reflecting growing human settlements. However, temporal and spatial resolution for these transitions is limited by a hiatus in the sediment record. We present a suite of carbon isotope data from 14C-dated vertebrate bones from Anjohibe Cave, northwestern Madagascar. In agreement with palynological records, isotope data indicate that the transition to open savannah may be a recent phenomenon in northwestern Madagascar. We document dramatic changes in the vertebrate community over the past 2000 years. Remains from extinct taxa are all older than 1500 cal. BP, locally extirpated taxa were in the region until c. 300 years ago, and introduced species are essentially modern. Stable carbon data suggest minimal consumption of C4 resources by extinct, locally extirpated and locally extant endemic taxa. On the contrary, introduced rats and shrews exhibit exceptionally high carbon isotope values; this may reflect a dietary shift to newly introduced grasses or consumption of seeds from C4 plants.