Southwestern Madagascar Research Articles

The supply of illegal tortoise meat to Toliara City, south-western Madagascar

AbstractA range of endemic and protected vertebrate species from Madagascar are threatened by the demand for bushmeat. We report on the number of discarded carapaces from illegally killed Critically Endangered radiated tortoisesAstrochelys radiatain an urban centre in south-west Madagascar. Through covert monitoring of public rubbish dumps we observed 1,913 carapaces during July 2010–January 2014. There was notable spatial and temporal variation, with some evidence of peaks in carapace dumping during May–June and October–December. A single rubbish dump near the artisanal fishery landing beaches accounted for 93% of the observed carapaces.

Social-ecological traps hinder rural development in southwestern Madagascar

The semiarid Mahafaly region in southwestern Madagascar is not only a unique biodiversity hotspot, but also one of the poorest regions in the world. Crop failures occur frequently, and despite a gr ...

Paulianesthes fouquei sp. nov., the second species of the endemic genus from Madagascar (Coleoptera: Tenebrionidae: Tentyriini)

The tenebrionid tribe Tentyriini (without Epitragini) was known from Madagascar only from three endemic and so far monotypic genera (Nothrocerus Fairmaire, 1891, Rhomaleus Chatanay, 1915, and Paulianesthes Koch, 1962). New collections prove the presence of a second species of Paulianesthes in southwestern Madagascar, being described in the present paper. Paulianesthes fouquei sp. nov. was found by pitfall traps on sandy soil in a small piece of forest with grazing cattle and sheep.

Boys go fishing, girls work at home: gender roles, poverty and unequal school access among semi-nomadic fishing communities in South Western Madagascar

Drawing from data gathered in South Western Madagascar in 2011, the work explores the combination of poverty and traditional gender roles as a critical factor in determining unequal school access among young people from semi-nomadic fishing communities. It demonstrates that from the age of early puberty, most boys go fishing with their fathers and brothers whilst most girls from the same families work at home. In contrast to the school systems observed in many developing society contexts, which demonstrate female marginalisation, in South Western Madagascar both boys and girls are marginalised. Instruments of global policy designs, such as positive discrimination for girls, seem ill-suited to resolve the problem. Instead, the authors call for a more tailored and context-specific approach to address the particular challenges amongst semi-nomadic fishing communities in Madagascar.

Assessment of food self-sufficiency in smallholder farming systems of south-western Madagascar using survey and remote sensing data

Madagascar is among the countries with a very high level of poverty and food insecurity. This holds particularly true for the south-western (SW) region with its chronic food shortages. Information on crop production, food availability and coping strategies of smallholders to deal with food shortages are scarce but urgently needed to assess the local food security status for more effective land management planning and famine prevention. This study, therefore, investigated farmers' coping strategies and determined the food security index (FSI), the food self-sufficiency ratio (FSSR) and cassava self-sufficiency (CSS) at the household level in three typical villages of the Mahafaly region in SW Madagascar. To this end we used household consumption surveys, land use mapping, crop field measurements, allometric equations and canopy cover estimations from aerial photographs for cassava yield assessments. For the majority of sampled households the daily calorie intake was insufficient (FSI<1) and the most frequent food insecurity coping strategies encountered were collection of wild food, off-farm activities and a reduction of meals. There was a high seasonal variation in food consumption, FSI and FSSR with different patterns on the plateau and in the coastal area. The main factors influencing FSSR were cassava yield, the livestock richness and landholding, whereas the number of off-farm activities determined FSI. Altogether, our results revealed that annual cultivated food crops provided up to 64% of people's diet. Cassava was the most important staple and played a key role for food self-sufficiency. However, cassava yields averaged only 0.69tha−1 and CSS ranged between 39 and 54%. Although there exists a high climate-induced risk in crop production, there is still room for improvements of agricultural techniques to enhance food self-sufficiency. However, enhancing access to off-farm income opportunities is similarly important to sustain local livelihoods in the long-term.

Reproductive and economic performance of local livestock in southwestern Madagascar: Potentials and constraints of a highly extensive system

In the dry Mahafaly region of southwestern Madagascar, livestock keeping plays a key role in people's livelihoods. Especially zebu cattle and goats are socially important and contribute considerably to regular income of local households. We therefore analyzed the reproductive performance of local breeds along with livestock owners' culling strategies to determine herd dynamics, opportunities for economic development, as well as potential improvements, by using a combined methodical, both production-oriented and economic approach. Data was collected through interviews on the progeny history of breeding females (506 cows and 593 does) and their offspring (721 calves and 1073 kids). Based on the results, reproduction parameters were calculated and entered into the PRY Herd Life model to simulate herd development for present management (status quo) and two alternate scenarios assuming either (i) improved feeding and resulting higher productivity of breeding females or (ii) improved culling. Based on prices collected at local markets, a Monte Carlo simulation was used to estimate annual costs and revenues from livestock keeping.Age at first parturition was 40.5±11.2months for cattle and 21.3±9.8months for goats. Females from both species showed long parturition intervals (cattle 24.2±8.7months, goats 12.4±5.7months) whereas reported offspring mortality was low with 2.5% of cattle and 18.8% of goats dying before reaching maturity. On the other hand, market prices, especially for zebus, were quite high, leading to annual contribution margins of 33 € per cattle unit and 11 € per goat unit. The simulations indicated that improved feeding could support substantial herd expansion and productive offtake rates, whereas improved culling would stabilize livestock numbers and concomitantly increase monetary herd output.Even though the current livestock husbandry system appears profitable, it might reach its limits in the near future due to the region's restricted ecological carrying capacity. Increasing livestock offtake would allow livestock keepers to raise their economic benefit without compromising herd development or enhancing the pressure on pasture resources.

Paternity in wild ring-tailed lemurs (Lemur catta): Implications for male mating strategies.

1In group‐living species with male dominance hierarchies where receptive periods of females do not overlap, high male reproductive skew would be predicted. However, the existence of female multiple mating and alternative male mating strategies can call into question single‐male monopolization of paternity in groups. Ring‐tailed lemurs (Lemur catta) are seasonally breeding primates that live in multi‐male, multi‐female groups. Although established groups show male dominance hierarchies, male dominance relationships can break down during mating periods. In addition, females are the dominant sex and mate with multiple males during estrus, including group residents, and extra‐group males—posing the question of whether there is high or low male paternity skew in groups. In this study, we analyzed paternity in a population of wild L. catta from the Bezà Mahafaly Special Reserve in southwestern Madagascar. Paternity was determined with 80–95% confidence for 39 offspring born to nine different groups. We calculated male reproductive skew indices for six groups, and our results showed a range of values corresponding to both high and low reproductive skew. Between 21% and 33% of offspring (3 of 14 or three of nine, counting paternity assignments at the 80% or 95% confidence levels, respectively) were sired by extra‐troop males. Males siring offspring within the same group during the same year appear to be unrelated. Our study provides evidence of varying male reproductive skew in different L. catta groups. A single male may monopolize paternity across one or more years, while in other groups, >1 male can sire offspring within the same group, even within a single year. Extra‐group mating is a viable strategy that can result in extra‐group paternity for L. catta males.

RADIOGRAPHIC AND ULTRASONOGRAPHIC ABDOMINAL ANATOMY IN CAPTIVE RING-TAILED LEMURS (LEMUR CATTA).

The ring-tailed lemur (Lemur catta) is primarily distributed in south and southwestern Madagascar. It is classified as an endangered species by the International Union for Conservation of Nature. Various abdominal diseases, such as hepatic lipidosis, intestinal ulcers, cystitis, urinary tract obstruction, and neoplasia (e.g., colonic adenocarcinoma and cholangiocarcinoma), have been reported in this species. The aim of this study was to describe the normal radiographic and ultrasonographic abdominal anatomy in captive ring-tailed lemurs to provide guidance for clinical use. Radiography of the abdomen and ultrasonography of the liver, spleen, kidneys, and urinary bladder were performed in 13 and 9 healthy captive ring-tailed lemurs, respectively, during their annual health examinations. Normal radiographic and ultrasonographic reference ranges for abdominal organs were established and ratios were calculated. The majority (12/13) of animals had seven lumbar vertebrae. The sacrum had mainly (12/13) three segments. Abdominal serosal detail was excellent in all animals, and hypaxial muscles were conspicuous in the majority (11/13) of animals. The spleen was frequently (12/13) seen on the ventrodorsal (VD) view and rarely (3/13) on the right lateral (RL) view. The liver was less prominent and well contained within the ribcage. The pylorus was mostly (11/13) located to the right of the midline. The right and left kidneys were visible on the RL and VD views, with the right kidney positioned more cranial and dorsal to the left kidney. On ultrasonography, the kidneys appeared ovoid on transverse and longitudinal views. The medulla was hypoechoic to the renal cortex. The renal cortex was frequently (8/9) isoechoic and rarely (1/9) hyperechoic to the splenic parenchyma. The liver parenchyma was hypoechoic (5/5) to the renal cortex. Knowledge of the normal radiographic and ultrasonographic abdominal anatomy of ring-tailed lemurs may be useful in the diagnosis of diseases and in routine health examinations.

Host age, social group, and habitat type influence the gut microbiota of wild ring-tailed lemurs (Lemur catta).

The gut microbiota contributes to host health by maintaining homeostasis, increasing digestive efficiency, and facilitating the development of the immune system. The composition of the gut microbiota can change dramatically within and between individuals of a species as a result of diet, age, or habitat. Therefore, understanding the factors determining gut microbiota diversity and composition can contribute to our knowledge of host ecology as well as to conservation efforts. Here we use high-throughput sequencing to describe variation in the gut microbiota of the endangered ring-tailed lemur (Lemur catta) at the Bezà Mahafaly Special Reserve (BMSR) in southwestern Madagascar. Specifically, we measured the diversity and composition of the gut microbiota in relation to social group, age, sex, tooth wear and loss, and habitat disturbance. While we found no significant variation in the diversity of the ring-tailed lemur gut microbiota in response to any variable tested, the taxonomic composition of the gut microbiota was influenced by social group, age, and habitat disturbance. However, effect sizes were small and appear to be driven by the presence or absence of relatively low abundance taxa. These results suggest that habitat disturbance may not impact the lemur gut microbiota as strongly as it impacts the gut microbiota of other primate species, highlighting the importance of distinct host ecological and physiological factors on host-gut microbe relationships. Am. J. Primatol. 78:883-892, 2016. © 2016 Wiley Periodicals, Inc.

Analysis of GPS trajectories to assess spatio-temporal differences in grazing patterns and land use preferences of domestic livestock in southwestern Madagascar

In order to investigate spatial and temporal characteristics of the purely grazing-based livestock husbandry system in southwestern Madagascar, individual animals from 12 cattle and 12 goat herds that were equally distributed across four villages were fitted with GPS tracking collars and their behaviour during pasturing was directly observed to identify seasonal variations in land use and movement patterns along the regional altitude and vegetation gradient. Monitoring occurred at regular intervals of two months over a two-year period to capture inter-annual variability. Herds of both species from the inland limestone plateau covered longer distances and were found further away from their home corrals than those from the coastal plain. Patterns of feeding behaviour and utilization of grazing areas mostly reflected the spatial occurrence of specific land cover classes around the villages and differed significantly between seasons and sites. Seasonal water shortage was one of the key factors affecting dry season livestock movements on the plateau but played a minor role in the coastal plain where livestock keeping proved to be more limited by feed availability. While on transhumance, mobile cattle herds were vulnerable to disadvantages such as limited access to pastureland and water sources nearby their temporary homesteads. The recent problem of armed cattle raids along with emerging land use conflicts compel livestock owners to utilize fewer grazing areas, which threatens to destabilize the region’s animal husbandry system.

Effects of goat grazing and woody charcoal production on xerophytic thickets of southwestern Madagascar

The effects of goat grazing and woody charcoal production are analysed on the diversity, structure, production and regeneration of the xerophytic thickets in southwestern Madagascar. Twenty (20 × 20) m2 plots were sampled according to soil type (yellow sand and calcareous) and disturbance intensities (low: ungrazed and no woody charcoal production; high: grazed and with woody charcoal production). Woody charcoal production reduced shrub density and biomass and affected species composition on yellow sand soil. In contrast, goat grazing alone did not significantly affect the diversity, mean height, stem and leaf biomass or species composition of xerophytic thickets on calcareous soil. However, shrub regeneration rate was low on both grazed and ungrazed sites. Rainfall variability may be the reason for this low regeneration. Goat grazing at a moderate stocking rate (∼1 head per ha) does not affect xerophytic thickets communities (plant diversity, biomass, regeneration rate). This finding indicates a need to (i) emphasize individual case studies that help to manage shrub pasture in semi arid regions, and (ii) avoid broad generalisations about the negative effects of goats on dry vegetation. Furthermore, goat breeding may be a viable alternative to woody charcoal production in these xerophytic thickets.

Interannual variability of rainfall characteristics over southwestern Madagascar

The interannual variability of daily frequency of rainfall [>1 mm/day] and heavy rainfall [>30 mm/day] is studied for the southwestern region of Madagascar, which is relatively arid compared to the rest of the island. Attention is focused on the summer rainy season from December to March at four stations (Morondava, Ranohira, Toliara and Taolagnaro), whose daily rainfall data covering the period 1970–2000 were obtained from the Madagascar Meteorological Service. El Nino Southern Oscillation (ENSO) was found to have a relatively strong correlation with wet day frequency at each station and, particularly, for Toliara in the extreme southwest. In terms of seasonal rainfall totals, most El Nino (La Nina) summers receive below (above) average amounts. An ENSO connection with heavy rainfall events was less clear. However, for heavy rainfall events, the associated atmospheric circulation displays a Southern Annular Mode-like pattern throughout the hemisphere. For ENSO years and the neutral seasons 1979/80, 1981/82 which had large anomalies in wet day frequency, regional atmospheric circulation patterns consisted of strong anomalies in low-level moisture convergence and uplift over and near southwestern Madagascar that made conditions correspondingly more or less favourable for rainfall. Dry (wet) summers in southern Madagascar were also associated with an equatorward (poleward) displacement of the ITCZ in the region.

Colonial memory, hospitality and tourism in southwestern Madagascar

Drawing on ethnographic data collected in a coastal village in southwestern Madagascar, the work explores the concept of memory through a study of contemporary hospitality practices aimed towards western tourists and other outsiders. The key observation is that memory is shaped by the interactions between two forms of colonial legacy. One is defined by the socially inscribed memory of past relations with powerful outsiders, mediated through myth and oral history. The other is defined by socially incorporated practices formed in the pre-colonial and colonial realms of the 19th and 20th centuries (and hence constitute a memory of such pasts in the present), and that today shift in the context of contact with western tourists and other foreigners. The main argument is that socially inscribed memory provides a highly flexible operational metaphor to mediate and also reproduce the socially incorporated practice-memory of hospitality, especially when historical symbolic functions - for example domesticating royals, colonial administrators, settlers, merchants or clerics - are shifted into contemporary contact zones with western tourists.

Colonial memory, hospitality and tourism in southwestern Madagascar

Colonial memory, hospitality and tourism in southwestern Madagascar

Effects of transhumance route on the richness and composition of bird communities in Tsimanampesotse National Park

In southwestern Madagascar, livestock (cattle) is a major source of income for the human population and is of tremendous cultural importance. In this subarid region, the farming system faces an extreme climate and has to cope with little food and water resources for several months a year. Local farmers overcome these difficulties in the form of transhumance and roaming of cattle in the forest at Tsimanampesotse National Park. The former strategy uses routes directly through the park twice per year. To assess possible effects of the transhumance and associated human activities on birds, we compared the composition and abundance of birds at one control site and two sites along the trail of transhumance in the forest of Tsimanampesotse National Park from January to May 201 2. The results showed that the abundance of birds declined near the trail of transhumance. Ten species of birds were hunted during the transhumance to meet the daily needs of the herders. We interpret the lower density of birds along the trail of transhumance as a consequence of hunting, especially for large and terrestrial birds such as Coua spp. Cattle activities (trampling, grazing) do not seem to bird communities.

Ecological and cosmological coexistence thinking in a hypervariable environment: causal models of economic success and failure among farmers, foragers, and fishermen of southwestern Madagascar.

A fact of life for farmers, hunter-gatherers, and fishermen in the rural parts of the world are that crops fail, wild resources become scarce, and winds discourage fishing. In this article we approach subsistence risk from the perspective of “coexistence thinking,” the simultaneous application of natural and supernatural causal models to explain subsistence success and failure. In southwestern Madagascar, the ecological world is characterized by extreme variability and unpredictability, and the cosmological world is characterized by anxiety about supernatural dangers. Ecological and cosmological causes seem to point to different risk minimizing strategies: to avoid losses from drought, flood, or heavy winds, one should diversify activities and be flexible; but to avoid losses caused by disrespected spirits one should narrow one’s range of behaviors to follow the code of taboos and offerings. We address this paradox by investigating whether southwestern Malagasy understand natural and supernatural causes as occupying separate, contradictory explanatory systems (target dependence), whether they make no categorical distinction between natural and supernatural forces and combine them within a single explanatory system (synthetic thinking), or whether they have separate natural and supernatural categories of causes that are integrated into one explanatory system so that supernatural forces drive natural forces (integrative thinking). Results from three field studies suggest that (a) informants explain why crops, prey, and market activities succeed or fail with reference to natural causal forces like rainfall and pests, (b) they explain why individual persons experience success or failure primarily with supernatural factors like God and ancestors, and (c) they understand supernatural forces as driving natural forces, so that ecology and cosmology represent distinct sets of causes within a single explanatory framework. We expect that future cross-cultural analyses may find that this form of “integrative thinking” is common in unpredictable environments and is a cognitive strategy that accompanies economic diversification.

Income diversification, wealth, education and well-being in rural south-western Madagascar: Results from the Mahafaly region

Rural households in the Mahafaly region of south-western Madagascar have to contend with low economic development and a risky natural environment. A survey of 665 households in the region was designed to address three research questions: what is the relationship between diversification of income sources and household wealth; how does education influence access to non-farm income sources and diversification; and how does household wealth and diversification affect well-being? The results show that the overwhelming majority of households follow a diversification strategy. Household wealth is associated with larger fields, greater crop diversity and higher diversification of income source categories. Education enhances access to high-return, non-farm income sources. Self-reported well-being is positively affected by both wealth and diversification. Better education and measures to improve inhabitants’ existing strategies for compensation of yield losses in farming are crucial for securing local livelihoods in the face of decreasing precipitation due to climate change.

Testing the Influence of Habitat Structure and Geographic Distance on the Genetic Differentiation of Mouse Lemurs (Microcebus) in Madagascar

The evolution of the high level of microendemism in Madagascar’s biota remains poorly understood. Allopatric speciation or adaptations to local conditions along continuous gradients are two mechanisms that could have contributed to the extraordinary radiation of lemurs. Here we tested whether mouse lemurs (Microcebus griseorufus) occurring across three adjacent but distinct vegetation formations (ranging from dry forest to spiny bush) in southwestern Madagascar showed signs of genetic differentiation that could be interpreted as incipient speciation and adaptation to different environmental conditions using analysis of molecular variance and distance-based redundancy analysis. In the context of a mark-recapture study, mouse lemurs were captured with Sherman live traps set eight times for four nights per trapping session in standardized trapping grids in the three vegetation formations between October 2007 and February 2009. For genetic analyses, we used tissue samples from 41 female and 35 male M. griseorufus. Genetic differentiation between demes as estimated by amplified fragment length polymorphism (AFLP) data (as parental markers) and mitochondrial D-loop sequences (as maternally inherited markers) was more pronounced in philopatric females than in males, which are the dispersing sex in this species. In single-factor analyses, isolation-by-ecology had about the same statistical effect as isolation by distance, but isolation-by-ecology was no longer significant once isolation by distance was taken into account. Despite some differentiation between local demes, STRUCTURAMA, a Bayesian approach for inferring population structure from genetic data, assigned all individuals to a single population. Thus, we did not find evidence for incipient ecological speciation as a result of adaptation to the three investigated habitat types on a small geographic scale based on the available samples.

Coastal Talitridae (Amphipoda: Talitroidea) from north-western Australia to Darwin with a revision of the genus Cochinorchestia Lowry & Peart, 2010.

Three species of coastal talitrids are reported from north-western Western Australia: Australorchestia tantabiddyensis sp. nov., from Tantabiddy Rockholes Cave, Cape Range National Park; Talorchestia dampieri sp. nov. from Roebuck Bay, Broome and Cygnet Bay, King Sound; and Tropicorchestia derbyensis gen. et sp. nov. from Derby, King Sound. Five species are reported from west of Darwin, Northern Territory: Cochinorchestia lindsayae sp. nov.; Cochinorchestia metcalfeae sp. nov.; Floresorchestia limicola (Haswell, 1880); Microrchestia ntensis sp. nov.; and Tropicorchestia glasbyi sp. nov. The genus Cochinorchestia Lowry & Peart, 2010 is revised: Orchestia notabilis of Griffiths, 1973 is assigned to the new species Cochinorchestia morrumbene sp. nov. from Mozambique; Orchestia sp. of Ledoyer, 1979 is assigned to the new species Cochinorchestia poka sp. nov. from Ambon, eastern Indonesia; and Orchestia notabilis of Ledoyer 1986 is assigned to the new species Cochinorchestia tulear sp. nov. from south-western Madagascar. Microrchestia sp. of Bussarawich 1985 appears to be an undescribed species of Cochinorchestia from Thailand. We introduce the term virgula dentata to describe the highly modified tip of antenna 2 in talitrid amphipods and propose a theory for the age and current distribution of the family.

Modelling the distribution of four Dioscorea species on the Mahafaly Plateau of south-western Madagascar using biotic and abiotic variables

Wild yam species (Dioscorea spp.) provide important supplementary food and thus contribute directly to the livelihood and well-being of local people in SW Madagascar. Given the ongoing exploitation of this resource, there is a necessity to identify and predict yam species distribution along environmental gradients to improve our understanding of sustainable management of this resource. Therefore, the aims of the current study were to identify predictors for the distribution of important wild yam species and to spatially predict their availability. To this end species abundance and environmental variables were collected in the field using a systematic sampling approach within a yams collection area of four villages (58 plots). A redundancy analysis (RDA) was conducted to investigate the relationship between wild yam species and 12 environmental variables. Species distribution models and species response curves were established for the most abundant wild yam species using nonparametric multiplicative regression (NPMR). These models were subsequently used in conjunction with geospatial data for predictive mapping. RDA depicted a clear pattern of species habitats with D. alatipes occurring in dry spiny forests on calcareous soils at remote places, while D. bemandry and D. fandra were found in forest habitats on sandy soils with high harvest intensities. The NPMR models explained 88% (D. alatipes), 82% (D. bemandry) and 37% (D. fandra) of the variation in species abundance. Sensitivity analysis indicated the importance of vegetation structure, human interventions, and soil characteristics in determining wild yam distribution. Predicted distribution maps showed that the population of wild yam is scarce and mostly located in restricted areas of open spiny forests and dry spiny forest thickets, where harvest intensity is high. This study highlights the need for long-term assessment and public awareness actions on yam harvest practices as well as the importance of anthropogenic factors for the distribution of yam as a key forest resource in SW Madagascar.