Eastern Madagascar Research Articles

Qualitative and Quantitative Evidence on the True Local Welfare Costs of Forest Conservation in Madagascar: Are Discrete Choice Experiments a Valid ex ante Tool?

Summary Protected areas may impose local welfare costs through the enforcement of use restrictions. Predicting their welfare impacts before their establishment could help with the design of compensation schemes. Discrete choice experiments (DCEs) are increasingly used for ex ante evaluations but their validity is largely untested in low-income settings. Using a case study of a new REDD+ (Reducing Emissions from Deforestation and forest Degradation) project in eastern Madagascar, we explore the validity of DCEs in two ways: (i) whether the estimates of welfare costs derived from DCE are affected by respondents’ prior experience of conservation (ii) whether DCE results have high theoretical and content validity. We surveyed households who have varying degrees of experience of restrictions to swidden agriculture. We also qualitatively debriefed a sub-sample of respondents to better understand their thought processes. Latent class analysis shows that DCE outcomes vary with conservation experience. Households more experienced with forest protection are less willing to trade-off rights to clear forest for swidden agriculture with any compensatory interventions whereas less experienced households highly favor support for alternative agricultural techniques and a secure right to clear one hectare of forest. Although the results show apparent non-attendance to some attributes (e.g., cash payments), qualitative debriefings suggest that respondents infact do expect relatively low or no utility from the given attributes and hence have theoretically valid preferences. Similarly, the DCE has generally high content validity. Although DCE can elicit current preferences in this context, using ex ante DCE to estimate the welfare costs of such a long-term intervention requires caution. We conclude that it is difficult to robustly estimate compensation in advance of an intervention, there is therefore a need to rethink conservation approaches, and the feasibility of achieving fair compensations for conservation-imposed restrictions.

Spatial imprints of plate tectonics on extant richness of terrestrial vertebrates

AbstractAimIn interaction with past climate changes, it is likely that plate tectonics contributed to the shaping of current global species diversity, but so far this has not been statistically quantified at the global level. Here, we tested whether plate tectonics since the breakup of Gondwana left an imprint on current patterns of species richness of amphibians, birds and mammals.LocationGlobal.MethodsWe reconstructed the absolute positions of continental plates since the Early Cretaceous and used this information to derive variables of latitudinal shifts and potential exchanges among landmasses that could have modulated species richness. Using a multi‐model inference approach combining both contemporary and historical variables, we quantified the relative importance of variables related to plate tectonics in explaining the spatial variation of the richness of amphibians, birds and mammals. Next, we employed a moving window approach to test whether plate tectonics left a more marked imprint in specific regions.ResultsPlate tectonics left an imprint on current patterns of vertebrate species richness in geologically singular regions, especially in the Indo‐Australian Archipelago and the region comprising eastern Africa and Madagascar. For birds and mammals, but not amphibians, we found a marked contrast in species richness across Australia and Southeast Asia and eastern Africa and Madagascar associated with plate tectonics. Moreover, the relationship between species richness and plate tectonics varied across taxonomic orders for birds and mammals.Main conclusionsWhile no general imprint of plate tectonics was detected at the global scale, our regional analysis highlighted a substantial role of geodynamics in shaping current patterns of vertebrate species richness in Southeast Asia and Madagascar. Future studies should integrate the full range of processes associated with plate tectonics, including orogeny, not considered here.

Rediscovery of two species of Croton (Euphorbiaceae) from littoral habitats of eastern Madagascar

Abstract Kainulainen, K., P.E. Berry & B. Van Ee (2017). Rediscovery of two species of Croton (Euphorbiaceae) from littoral habitats of eastern Madagascar. Candollea 72: 35–44. In English, English and French abstracts. Two species of Croton L. (Euphorbiaceae) previously reported only from their type specimens, Croton chapelieri Baill. and Croton vatomandrensis Leandri, are reevaluated here and found to be geographically widespread along the eastern coastline of Madagascar. We provide updated descriptions, lists of selected additional specimens, distribution maps, and photographs of both species. We also designate an epitype for Croton chapelieri and a lectotype for Croton vatomandrensis. Croton chapelieri was the source of considerable taxonomic confusion, and we treat as synonyms here for the first time Croton aymoninorum Leandri, Croton louvelii Leandri, Croton daphniphylloides Radcl.-Sm., Croton daphniphyllum Radcl.-Sm., Croton daphniphyllum var. hirsutus Radcl.-Sm., and Croton rhododendroides Radcl-Sm...

Two New Species of Sucking Lice (Phthiraptera: Anoplura: Polyplacidae) From Endangered, Hibernating Lemurs (Primates: Cheirogaleidae).

Lemurpediculus robbinsi sp. nov. is described from Crossley's dwarf lemur, Cheirogaleus crossleyi A. Grandidier, and Lemurpediculus claytoni sp. nov. is described from Sibree's dwarf lemur, Cheirogaleus sibreei Forsyth Major, from Madagascar. Both sexes of each new louse species are illustrated and distinguished from the two previously known species of Lemurpediculus: L. verruculosus (Ward) and L. petterorum Paulian. With the addition of two new species to the genus, an amended description of Lemurpediculus is provided. The two hosts of the new louse species are morphologically similar, endangered, obligately hibernating lemurs. These two species of lemurs are sometimes sympatric in rainforests in eastern Madagascar. Despite the morphological similarity of the two host species, their lice are morphologically distinct and are easiest to identify based on the shape of the subgenital plate of the female and the shape of the genitalia in the male. Both new species of lice should be considered to be endangered because their hosts are endangered. It is not known if either of the new species of lice are vectors of pathogens or parasites to their hosts.

Rebuilding soil hydrological functioning after swidden agriculture in eastern Madagascar

Land-use change due to the widespread practice of swidden agriculture affects the supply of ecosystem services. However, there is comparatively little understanding of how the hydrological functioning of soils, which affects rainfall infiltration and therefore flood risk, dry-season flows and surface erosion, is affected by repeated vegetation clearing and burning, the extent to which this can recover following land abandonment and vegetation regrowth, and whether active restoration speeds up recovery. We used interviews with local land users and indicator plant species to reconstruct the land-use history of 19 different sites in upland eastern Madagascar that represent four different land-use categories: semi-mature forests that were never burnt but were influenced by manual logging until 15–20 years ago; fallows that were actively reforested 6–9 years ago; 2–10year old naturally regenerating fallows; and highly degraded fire-climax grassland sites. Surface- and near-surface (down to 30cm depth) saturated soil hydraulic conductivities (Ksat), as well as the dominant flow pathways for infiltration and percolation were determined for each land-cover type. Surface Ksat in the forest sites was very high (median: 724mmh−1) and infiltration was dominated by flow along roots and other preferential flow pathways (macropores), whereas Ksat in the degraded land was low (median: 45mmh−1) with infiltration being dominated by near-surface matrix flow. The total area of blue-dye stains was inversely correlated to the Ksat. Both surface- and near-surface Ksat had increased significantly after 6–9 years of forest regeneration (median values of 203 and 161mmh−1 for reforestation and natural regeneration, respectively). Additional observations are needed to more fully understand the rates at which soil hydrological functioning can be rebuilt and whether active replanting decreases the time required to restore soil hydrological functioning or not.

Predation on Subfossil Prolemur simus by Multiple Predator Species at Ankarana Massif, Northern Madagascar

Evidence of historic predation is important to understand the role that predators play in molding fundamental aspects of primate biology. We examined the geographic demise of Prolemur simus from the perspective of its past behavioral ecology. Using paleontological data from the Late Pleistocene–Holocene deposits at Ankarana Massif, northern Madagascar, we test the hypothesis that 1) multiple predators preyed on P. simus in the past and 2) the dietary preferences and habitat preferences of subfossil P. simus were similar to its extant counterpart. We examined 381 subfossil craniodental remains of P. simus from Ankarana. We used dental eruption and macrowear to assign craniodental remains to relative age classes, and carbon (δ13C) and nitrogen (δ15N) stable isotope values in bone collagen to assess variation in this species’ diet and habitat. Skeletal evidence of predation suggests that multiple predators consumed P. simus in the past. Evidence for carnivoran predatory activity includes punctures on the viscerocranium, posterior neurocranium, and angle of the mandible. Evidence for raptor predatory activity includes talon nicks, punctures, and “can-opener” perforations within the orbits or palate. Stable isotope data suggest that the diet of P. simus was remarkably similar among localities inhabited by this species before human arrival, despite varied environmental conditions. These data suggest that P. simus was likely codistributed with large-culmed bamboo in the past as it is today. The synergistic effects of predation and habitat change may explain the biogeographic retreat of P. simus to its present-day distribution in eastern Madagascar. The study of predator–primate dynamics and interactions across contiguous and fragmented forests will increase our understanding of the impact of such dynamics on primate evolution, and improve primate conservation efforts more broadly.

Avian malaria on Madagascar: bird hosts and putative vector mosquitoes of different Plasmodium lineages

BackgroundAvian malaria occurs almost worldwide and is caused by Haemosporida parasites (Plasmodium, Haemoproteus and Leucocytozoon). Vectors such as mosquitoes, hippoboscid flies or biting midges are required for the transmission of these parasites. There are few studies about avian malaria parasites on Madagascar but none about suitable vectors.MethodsTo identify vectors of avian Plasmodium parasites on Madagascar, we examined head, thorax and abdomen of 418 mosquitoes from at least 18 species using a nested PCR method to amplify a 524 bp fragment of the haemosporidian mitochondrial cytochrome b gene. Sequences obtained were then compared with a large dataset of haemosporidian sequences detected in 45 different bird species (n = 686) from the same area in the Maromizaha rainforest.ResultsTwenty-one mosquitoes tested positive for avian malaria parasites. Haemoproteus DNA was found in nine mosquitoes (2.15%) while Plasmodium DNA was found in 12 mosquitoes (2.87%). Seven distinct lineages were identified among the Plasmodium DNA samples. Some lineages were also found in the examined bird samples: Plasmodium sp. WA46 (EU810628.1) in the Madagascar bulbul, Plasmodium sp. mosquito 132 (AB308050.1) in 15 bird species belonging to eight families, Plasmodium sp. PV12 (GQ150194.1) in eleven bird species belonging to eight families and Plasmodium sp. P31 (DQ839060.1) was found in three weaver bird species.ConclusionThis study provides the first insight into avian malaria transmission in the Maromizaha rainforest in eastern Madagascar. Five Haemoproteus lineages and seven Plasmodium lineages were detected in the examined mosquitoes. Complete life-cycles for the specialist lineages WA46 and P31 and for the generalist lineages mosquito132 and PV12 of Plasmodium are proposed. In addition, we have identified for the first time Anopheles mascarensis and Uranotaenia spp. as vectors for avian malaria and offer the first description of vector mosquitoes for avian malaria in Madagascar.

Amphibian Diversity in the Matrix of a Fragmented Landscape Around Ranomafana in Madagascar Depends on Matrix Quality

Human-induced conversion of natural habitats into agricultural areas is one of the major drivers for biodiversity loss. In many tropical regions, the matrix habitat area (habitat between fragments of remaining natural habitat) considerably exceeds the area of the original habitat. Therefore, understanding the factors determining matrix quality for animals is a key step to guide conservation action in fragmented landscapes. Matrix habitat, although being often highly disturbed, might provide valuable habitat for some species, serves as buffer zone for remaining natural habitat or corridor between fragments, and hence could be an important component for biodiversity maintenance on a landscape scale. We evaluated the effects of matrix quality on frog diversity in a rainforest ecosystem in Eastern Madagascar. Although frog diversity was affected in all matrix habitats, we found that variation in matrix quality was an important factor. Matrix habitat could serve as valuable habitat and corridor (i.e., high fro...

Interview: Madagascar’s rosewood stocks – which way to go?

For centuries, people around the globe have admired Rosewood. Malagasy rosewoods (Dalbergia spp.) are especially valued for their qualities. In recent years, illegal sourcing of rosewood escalated to unprecedented levels: this coincided with the political fallout from 2009-2013. The wood has been – and is - sourced mainly from protected areas in eastern Madagascar. Before being exported, timber is stockpiled, mostly in well-concealed localities. Despite an international ban on export and trading, the timber has been – and continues to – leave Madagascar. The species targeted are CITES listed, which means that trading them is forbidden. Most of the wood has been shipped to China, where demand for it is enormous. In 2011, stocks were estimated to be in excess of 500,000 tons. In 2013, the international community, spearheaded by the SADC were to prepare new presidential elections which were expected to put an end to the political and economic crisis of what is an increasingly beleaguered nation. In the same period, the World Bank implemented a project aimed at finding a solution of how to deal with the controversial rosewood stocks. At time of writing, this remains a topic of debate. Experts in a previous MCD interview suggested either to destroy the stocks in order to avoid further illegal sourcing of timber from protected areas, or to establish a timber bank of sorts. All agreed that selling the wood would be a double-edged sword: while it brings much- needed revenues to the empty coffers of the government, it may fuel and further increase demand for Rosewood. A noticeable and lengthy silence followed, with virtually no coverage in the national and international media. The World Bank project (#PO93271) comes to an end in December 2015: “all illegal precious woods stockpiles sized by Government have been audited and secured”. The journal MCD is asking the 2011 questions – four years later, and would like to give voice to some of the experts and practitioners involved in this rosewood crisis.

Gecko phylogeography in the Western Indian Ocean region: the oldest clade of Ebenavia inunguis lives on the youngest island

AbstractAimWe studied the gecko genus Ebenavia to reconstruct its colonization history, test for anthropogenic versus natural dispersal out of Madagascar, and correlate divergence date estimates of our phylogeny with geological age estimates of islands in the region.LocationMadagascar and surrounding islands of the Western Indian Ocean (Comoros, Mayotte, Mauritius, Pemba).MethodsWe reconstructed the phylogeny of Ebenavia covering its entire geographical range using a molecular data set of three mitochondrial and two nuclear markers. We estimated divergence times based on calibrations using (1) previously calculated mutation rates of mitochondrial markers, (2) a combination of these rates with old or (3) young geological age estimates for some of the islands inhabited by the genus, and (4) an independent data set with fossil outgroup calibration points.ResultsEbenavia inunguis, one of two recognized species of the genus, comprises multiple ancient evolutionary lineages. The earliest divergence within this complex (Miocene, 13–20 Ma; 95% credibility interval [CI]: 4–29 Ma) separates the population of the Comoros Islands, excluding Mayotte, from all other lineages. The age estimates for island lineages coincide with the geological age estimates of the islands except for Grand Comoro, where the age of the local clade (3–5 Ma; 95% CI: 2–7 Ma) significantly predates the estimated island age (0·5 Ma). A clade from north Madagascar + Mayotte + Pemba is estimated to have diverged from an eastern Malagasy clade in the Miocene.Main ConclusionsOur results suggest that Grand Comoro Island is geologically older than previously estimated. The islands of the Comoros and Pemba were probably colonized via natural dispersal out of Madagascar (> 1000 km in the case of Pemba). Mauritius was most likely colonized only recently from eastern Madagascar via human translocation.

Croton cupreolepis (Euphorbiaceae), a New Coppery-lepidote Tree Species from Eastern Madagascar

Abstract Croton cupreolepis (Euphorbiaceae) is newly described from montane, evergreen forests of eastern Madagascar. It is distinguished by its coppery-lepidote trichomes that form a dense covering on the floral buds and inflorescences, as well as on the dorsal side of the petals of both pistillate and staminate flowers, and also by its distinctive recurved pedicels. The young leaves are covered by the same type of coppery trichomes on the lower surface, but as the leaves expand, the coppery scales become scattered on a background of silvery scales. The species has been confused with Croton chrysodaphne, C. nobilis, or else specimens have been left determined just to genus. Its broad latitudinal distribution in Madagascar suggests that it may once have been more widespread, but has been a victim of the widespread deforestation of primary forest along the eastern slopes of the island.

New species and species reports of Croton L. (Euphorbiaceae) from the eastern forest corridor of Madagascar

Abstract Kainulainen, K., B. Van EE, P. Antilahimena, H. Razafindraibe & P.E.Berry (2016). New species and species reports of Croton L. (Euphorbiaceae) from the eastern forest corridor of Madagascar. Candollea 71: 327–356. In English, English and French abstracts. Six species of Croton from the Moramanga District of the Alaotra-Mangoro Region of eastern Madagascar (Toamasina Prov.) are newly described here, five of which occur in the Ambatovy mining concession. A seventh new species is described from the Ankerana Forest in the Atsinanana Region, some 80 km to the northeast of the town of Moramanga, which is one of the offset areas intended to mitigate the deforestation incurred by the Ambatovy mining project. Of the new species, Croton ferricretus Kainul., B.W. van Ee & P.E. Berry is the one most closely associated with the ultramafic soils where nickel and cobalt is being extracted. Although it is locally common, it is only known from the mine concession. Croton enigmaticus P.E. Berry & B.W. van Ee is co...

Competition for dead trees between humans and aye-ayes (Daubentonia madagascariensis) in central eastern Madagascar.

The destruction and degradation of forest habitats are major threats to the sustainability of lemur populations in Madagascar. Madagascan landscapes often contain forest fragments that represent refuges for native fauna, while also being used for firewood and timber by local human populations. As undisturbed forest becomes increasingly scarce, understanding resource competition between humans and wildlife in disturbed habitats will be increasingly important. We tested the hypothesis that Malagasy and aye-ayes (Daubentonia madagascariensis) compete for the limited number of dead trees in rainforest fragments at Tsinjoarivo, Madagascar. We surveyed 2.16 ha within five fragments (range 5-228ha) surrounding human settlements to quantify the density of dead trees and traces of both human and aye-aye activity. Neither aye-aye nor human traces were distributed according to the availability of particular trees species, and aye-ayes and Malagasy apparently preferred several different species. Although overlap was recorded in tree species used, human use tended to be positively correlated with a species' desirability as firewood, while a negative relationship was seen for aye-ayes. Both consumers used trees of similar diameter at breast height, but those used by aye-ayes tended to be older, suggesting that human use might precede usefulness for aye-ayes. Finally, the density of dead trees and aye-aye traces were highest in smaller fragments, but human traces did not vary across fragment size. Although further study is needed to better quantify the aye-aye diet in this region, these data suggest that aye-ayes and local people compete for dead trees, and this competition could constitute a pressure on aye-aye populations.

Subtropical surface circulation in the southern Indian Ocean derived from surface drifters

Using trajectory tracing method from 308 long-lived surface drifters, the subtropical surface circulations in the southern Indian Ocean (SIO) are investigated in the views of both Lagrangian and Euler.Analysis of the results from the Lagrangian view confirm the two pathways of seawater transport from high to low latitude based on different types of drifter trajectory. One pathway is that the seawater formed in high latitude flows northward along the eastern boundary of SIO, joints the westward South Equatorial Current (SEC), and reaches east of the Mozambique along the north side of the Madagascar Island, then bifurcates into northward and southward branches: the northward branch cross the equator and finally joints the north Indian Ocean circulation system; the southward branch meanders along the Mozambique Channel and forms a series of mesoscale eddies. The other pathway is that the seawater flows northward through the central SIO, then turns to west following the SEC, and flows back to the south when reaches the east of the Madagascar Island. Based on the trajectory of drifters, the mean life cycle of subtropical circulation is about 43±20 months. In Euler view, zonal and meridional velocity, mean kinetic energy (MKE), and eddy kinetic energy (EKE) are calculated in 0.5°×0.5° grid using Poulain’s method. The high MKE reaches over 1000 (cm/s)2 in the regions of South Equatorial Current, Agulhas Current/Agulhas Return Current, Eastern Madagascar Current, and Eastern African Coastal Current, the two latter of which are western boundary currents. The EKE has similar spatial distribution with the MKE in the region west of Australia. The spatial variations of current in several areas are significantly modulated by mesoscale eddies, such as in the regions of Agulhas Retroflection, western basin of SIO, and west of Australia. Agulhas system, especially in the area of Agulhas Retroflection, has highest MKE and EKE, due to the interaction with the bottom topography and the wind stress curl induced instability. West of Australia, the EKE is remarkably larger than the MKE due to active mesoscale eddies. In particular, Leeuwin Current can be detected by drifters in the region. For the South Indian Ocean Countercurrent (SICC), although previous studies suggested an eastward current near 25°S, this study does not find drifters following eastward along this proposed current. However, similar result in EKE distribution as previous studies suggest that the eddy activities are much more significant that the mean current in this proposed SICC region. Ocean surface drifters have important role in track the missing crafts. The long-lived drifters passing around the Reunion Island are collected and traced back to their origins and to rebuild the track of missing MH370’s wrecks. Three possible pathways are rebuilt and two possible crash sites are identified around 35°S, 95°E and 38°S, 92°E, which are consistent with former results from satellite but show more evidences and details. The latest news said that some wrecks were found in the coast of Mozambique, which can be further validated by analysis of drifter trajectories in this study. Along both pathways, passing by north or south of Madagascar Island, surface drifters can reach the coast of Mozambique in different landing time. Both the currents/circulations in the SIO basin and Mozambique Channel contribute to the routes of the wrecks. In this study, the subtropical surface circulation in the SIO is investigated from surface drifters, which help us to understand the mass transport between high and low latitude. A few puzzles still remain, such as there is none of trajectory supporting the SICC at the sea surface. The use of surface drifters on tracing the MH370’s wrecks provides a good try to search missing craft in the ocean, and thus suggests more possible applications in the future in this isolated ocean.

Measurement and modeling of rainfall interception by two differently aged secondary forests in upland eastern Madagascar

Secondary forests occupy a larger area than old-growth rain forests in many tropical regions but their hydrological functioning is still poorly understood. In particular, little is known about the various components of evapotranspiration in these possibly vigorously regenerating forests. This paper reports on a comparison of measured and modeled canopy interception losses (I) from a semi-mature (ca. 20years) and a young (5–7years) secondary forest in the lower montane rain forest zone of eastern Madagascar. Measurements of gross rainfall (P), throughfall (Tf), and stemflow (Sf) were made in both forests for one year (October 2014–September 2015) and the revised analytical model of Gash et al. (1995) was tested for the first time in a tropical secondary forest setting. Overall measured Tf, Sf and derived I in the semi-mature forest were 71.0%, 1.7% and 27.3% of incident P, respectively. Corresponding values for the young forest were 75.8%, 6.2% and 18.0%. The high Sf for the young forest reflects the strongly upward thrusting habit of the branches of the dominant species (Psiadia altissima), which favours funneling of P. The value of I for the semi-mature forest is similar to values reported for old-growth tropical lower montane rain forests elsewhere but I for the younger forest is higher than reported for similarly aged tropical lowland forests. These findings can be explained largely by the prevailing low rainfall intensities and the frequent occurrence of small rainfall events. The revised analytical model was able to reproduce measured cumulative I at the two sites accurately and succeeded in capturing the variability in I associated with the seasonal variability in rainfall intensity, provided that Tf-based values for the average wet-canopy evaporation rates were used instead of values derived with the Penman-Monteith equation.

Melody in my head, melody in my genes? Acoustic similarity, individuality, and genetic relatedness in the indris of Eastern Madagascar

Indris (Indri indri) are the only singing lemurs and produce different types of songs that can be differentiated according to their temporal patterns. The most distinctive portions of the songs are “descending phrases” consisting of 2-5 units. In our study, indri songs were recorded in the Eastern rainforests of Madagascar from 2005 to 2015. All the recordings were made when the recorder operator was in visual contact with the singing social group and by recognizing individual indris using natural markings. Because the individual songs frequently overlap during the chorus, we extracted the pitch contour of 1084 descending phrases using the program Praat. We tested whether the structure of the phrases could provide conspecifics with information about sex and individual identity. We also examined whether the structure of the phrases was related to the genetic relatedness of the indris. The results suggest that the songs have consistent sex-, group-, and individual-specific features. We have also found a significant correlation between the genetic distance and the acoustic similarity. The descending phrases may be used by the indris to convey information of sex and identity, and genetic relatedness may play a role in determining song similarity to a larger extent than previously assumed.

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 naive, 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.

The Changing Nature of Agricultural Livelihoods along a Peri-urban to Rural Gradient in Eastern Madagascar

Madagascar is one of the poorest countries in the world, but with high conservation value due to its many unique, endemic species. Rapid population growth and increasing poverty are leading to growing food insecurity and malnutrition especially in rural areas, putting ever more pressure on remaining natural resources. Ecoagriculture is seen as one approach to address these issues, but the success of introducing new practices is contingent on the specific local conditions and situation of individual households reflected in different livelihood strategies. In order to better orient agricultural training and technical assistance provided by the Madagascar Flora and Fauna Group (MFG), a short survey was done in villages in two areas where MFG operates, at different distance from and ease of access to the city of Tamatave: Parc Ivoloina and the Betampona Integral Nature Reserve. Results show that households in villages around Betampona largely continue to use traditional slash-and-burn methods, with future livelihoods remaining focused on agriculture based on primarily food crop production. Around Parc Ivoloina, households rely more and more on off-farm and non-farm income made possible by its close proximity to Tamatave. People do farm, but are switching to less labor demanding tree crops and livestock more compatible with off-farm jobs, and to keep ancestral land occupied to provide supplementary food and income. The results confirm that farmers are adaptive resource managers, flexibly redirecting their activities, practices and methods as economic and environmental conditions change or opportunities arise.

Genetic Analysis of the Indri Reveals No Evidence of Distinct Subspecies

Subspecies were traditionally defined by identifying gaps between phenotypes across the geographic range of a species, and may represent important units in the development of conservation strategies focused on preserving genetic diversity. Previous taxonomic research proposed that phenotypic variation between scattered Indri indri populations warranted the naming of two distinct subspecies, I. i. indri and I. i. variegatus. We tested these subspecific designations using mitochondrial sequence data generated from the control region or D-loop (569 bp) and a large section (2362 bp) of multiple genes and tRNAs known as Pastorini’s fragment and nuclear microsatellite markers. This study used 114 samples of I. indri from 12 rainforest sites in eastern Madagascar, encompassing the entire range of the species. These genetic samples represent multiple populations from low- and high-elevation forests from both putative subspecies. Molecular analyses of the mitochondrial sequence data did not support the two proposed subspecies. Furthermore, the microsatellite analyses showed no significant differences across the range beyond population level differentiation. This study demonstrates the utility of incorporating multiple lines of evidence in addition to phenotypic traits to define species or subspecies.

Genesis of the Tonian Imorona–Itsindro magmatic Suite in central Madagascar: Insights from U–Pb, oxygen and hafnium isotopes in zircon

Madagascar occupies an important location within the East African Orogen (EAO). The EAO comprises an assemblage of Neoproterozoic microcontinents and arc terranes lodged between older cratonic blocks during the final assembly of the supercontinent Gondwana. The Imorona–Itsindro Suite of central Madagascar represents voluminous Tonian-aged (850–750Ma) magmatism with controversial petrogenesis. Early work proposed arc magma generation coinciding with oceanic plate subduction during closure of the Mozambique Ocean along the ‘Betsimisaraka Suture’ in eastern Madagascar. Recently, others have questioned the existence of such a suture in Madagascar and rather suggest extension related emplacement into the middle and upper crust through a system of pre-existing structures. New U–Pb (zircon) geochronological data coupled with in-situ oxygen and hafnium isotopic analyses demonstrate that the Imorona–Itsindro Suite had several source components. Most of the Tonian-aged magmatic rocks were derived by mixing between ancient crust and mantle derived melts. δ18O values show variation that indicates significant involvement of crustal material and hydrothermal fluids. Predominantly low negative εHf(t) values are also variable and indicate significant crustal involvement in the genesis of the Tonian magmas. A compilation of all available geochronological data shows magmatism was essentially continuous for ∼100Myr but with periods of increased activity at ∼800Ma, ∼791Ma and ∼784Ma. Temporal analysis shows magmatic cycles of enrichment and depletion on the scale of 15–40Ma. Spatial variations in isotope compositions reflect the heterogeneity of probable crustal source rocks present in the Ikalamavony, Itremo, Antananarivo and Masora Domains. A tectonic model is proposed for the Imorona–Itsindro Suite as a long-lived Andean-like arc on the margin of the Mozambique Ocean. The longevity and temporal isotopic trends are interpreted as reflecting cycles of arc advance and retreat.