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Edge effects are caused by the penetration of abiotic and biotic conditions from the nonforest matrix into forest interiors. Edge effects are particularly relevant to studies of lemur conservation biogeography due to the high levels of forest loss and fragmentation on Madagascar. Moreover, climatic seasonality has influenced many aspects of lemur evolutionary ecology (e.g., diet and ranging patterns). Although lemurs are strongly influenced by seasonality and edge habitats are an increasingly dominant feature of their forest habitats, there are few data on whether or not any species exhibit seasonal responses to edge effects. In this study, we evaluated for the first time whether four lemur species (Avahi peyrierasi, Eulemur rubriventer, Hapalemur griseus ranomafanensis, and Microcebus sp.) exhibited seasonal variations in their edge proximities in SE Madagascar. We conducted diurnal (N = 348) and nocturnal (N = 134) lemur surveys along six transects over 3 years in the Vohibola III Classified Forest. The four lemur species exhibited considerable interspecific differences in the overall distribution and shape of their seasonal edge proximities. A. peyrierasi aggregated significantly further away from the forest edge during the warm, wet season than during the cool, dry season. The combination of a highly selected diet in A. peyrierasi and anthropogenic depletion of their preferred food and sleeping trees in edge habitats may explain seasonal changes in edge proximity. Lack of a seasonal edge effect in the other three lemur species likely reflects their ecological flexibility and in H. g. ranomafanensis and E. rubriventer, active defense of home-ranges and territories, respectively, from conspecifics. Further research is needed to better understand this new described pattern of seasonal variations in edge responses in lemurs. [ABSTRACT FROM AUTHOR]

Anthropogenic fire use is widespread across Madagascar and threatens the island's unprecedented endemic biodiversity. The vast majority (96%) of lemur species are already threatened with extinction, and Madagascar has already lost more than 44% of its forests. Previous conservation assessments have noted the role of fire in the rampant deforestation and habitat degradation across Madagascar, but published, quantified data on fire use across the island are incredibly limited. Here, we present the first quantification of spatiotemporal patterns in fire occurrence across Madagascar using VIIRS satellite fire detection data. We assess which regions of Madagascar have the most prevalent fire use, how fire use is changing over time, and what this means for Madagascar's remaining forest ecosystems. An average of 356,189 fires were detected every year in Madagascar from 2012–2019, averaging 0.604 fires/km2. Fire use was near-ubiquitous across the island, but was most prevalent in the western dry deciduous forests and succulent woodlands ecoregions. Fire frequency in the eastern lowlands was highest around the remaining humid rainforest, and fire frequency was increasing over time around much of the remaining humid and dry forest. We found that 18.6% of all remaining forest was within 500 m of a fire within a single year, and 39.3% was within 1 km. More than half of remaining forest was within 1 km of a fire in a single year in the dry deciduous forests, succulent woodlands, and mangroves ecoregions. However, fire frequency within national park protected areas was, on average, 65% lower than their surroundings. Only 7.1% of national park forest was within 500 m of a fire within one year, and 17.1% was within 1 km, suggesting that national parks are effective at reducing fire frequency in Madagascar's tropical forests. [ABSTRACT FROM AUTHOR]

Determining what factors affect species occurrence is vital to the study of primate biogeography. We investigated the metapopulation dynamics of a lemur community consisting of eight species (Avahi occidentalis, Propithecus coquereli, Microcebus murinus, Microcebus ravelobensis, Lepilemur edwardsi, Cheirogaleus medius, Eulemur mongoz, and Eulemur fulvus) within fragmented tropical dry deciduous forest habitat in Ankarafantsika National Park, Madagascar. We measured fragment size and isolation of 42 fragments of forest ranging in size from 0.23 to 117.7 ha adjacent to continuous forest. Between June and November 2011, we conducted 1218 surveys and observed six of eight lemur species (M. murinus, M. ravelobensis, C. medius, E. fulvus, P. coquereli, and L. edwardsi) in the 42 fragments. We applied among patch incidence function models (IFMs) with various measures of dispersal and a mainland-island IFM to lemur species occurrence, with the aim of answering the following questions: 1) Do lemur species in dry deciduous forest fragments form metapopulations? 2) What are the separate effects of area (extinction risk) and connectivity/isolation (colonization potential) within a lemur metapopulation? 3) Within simulated metapopulations over time, how do area and connectivity/isolation affect occurrence? and 4) What are the conservation implications of our findings? We found that M. murinus formed either a mainland-island or an among patch metapopulation, M. ravelobensis formed a mainland-island metapopulation, C. medius and E. fulvus formed among patch metapopulations, and neither P. coquereli or L. edwardsi formed a metapopulation. Metapopulation dynamics and simulations suggest that area was a more consistent positive factor determining lemur species occurrence than fragment isolation and is crucial to the maintenance of lemur populations within this fragmented landscape. Using a metapopulation approach to lemur biogeography is critical for understanding how lemur species respond to forest loss and fragmentation. [ABSTRACT FROM AUTHOR]

Lactating females face energetic constraints absent in conspecifics and must compensate for higher energy requirements. Infant transport is the most energetically costly mammalian activity after lactation. Nonetheless, infant transport and mother-infant contact are seldom measured. The extreme seasonality characteristic of Madagascar coupled with lactation costs and infant transport is a trifold energetic challenge encountered by lemur mothers. We hypothesized that Coquerel's sifaka ( Propithecus coquereli) mothers spend more time caring for infants during the early/earlier-mid lactation period, coinciding with the resource depletive austral winter, relative to later-mid/late lactation. We tested this hypothesis by measuring infant carrier identity, transport position, and frequency of mother-infant contact for 678 focal hours over two consecutive birth seasons from 1 to 26 weeks postnatal ( N = 10 infants, N = 10 mothers, N = 19 adult males, N = 8 adult females) in Ankarafantsika National Park (ANP), Madagascar. Quantifying P. coquereli postnatal care strategies demonstrates how a species with a 'slow' life history lives in an energetically challenging environment, thereby providing data on maternal energetic responses and infant development in an endangered strepsirrhine. Mothers were the primary infant transporters. Adult males and non-lactating females participated in infant transport, but for significantly less time. Infants spent significantly more time in the ventral transport position than dorsally or independently. Infants were still transported 26% of the time at 6.5 months postnatal. Infants initiated and broke bodily contact with mothers more frequently than mothers initiated and broke contact with infants. Infants were dependent on their mothers for longer durations than suggested by previous studies and carried dorsally until later ages than in other comparably sized wild lemurs. Am. J. Primatol. 78:646-658, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

I investigated ecological and phylogenetic correlates to body size variations in 10 taxa of extant Indriidae ( Indri, Avahi, and Propithecus). I also tested for phylogenetic niche conservatism as a model for the evolution of indriid body size. Phylogenetic niche conservatism refers to the shared attributes that related taxa have acquired because they tend to have occupied similar niches during their evolutionary history. I collected species-specific data on body mass, climate, density, and chemical properties of food items from the literature. I used 2 phylogenies in independent contrasts methods to control for phylogenetic relationships ( Indri and Propithecus as sister taxa vs. Indri basal taxa to all indriids). Multivariate models indicated that lemur density and resource quality are the strongest ecological correlates to indriid body size variations. Partitioning methods revealed that 52.4–67% of indriid body size variation is explained by phylogenetic niche conservation. Thus, indriid body size variations may be the result of stabilizing selection. Though it is possible to identify constraints on lower than average body size, there are few data on selection against larger than average body size in indriids. Large body size in subfossil lemurs further complicates identification of constraints on larger than average body size in extant indriids. Researchers using independent contrast methods to control for phylogeny should be aware that some ecology-phenotype relationships are best explained as the result of the synergistic effects of ecology and phylogeny. [ABSTRACT FROM AUTHOR]

We determined if data on strepsirhine body and home range sizes support an optimal body size (OBS) model of 100 g, as predicted from studies of energetics in terrestrial mammals. We also tested the following predictions of the OBS model: 1) relationships between body and home range sizes will change slope and sign above and below the OBS threshold of 100 g and 2) best-fit lines for OBS regression models (above and below the 100-g threshold) will intersect at ca. 100 g (range of 80–250 g). We collected data on body mass, home range size, and vertical ranging behavior for 37 strepsirhines from the literature. Linear regression analyses and phylogenetic independent contrasts methods revealed that body size is a significant determinant of both 2-dimensional (ha) and 3-dimensional (km3) home range sizes only in taxa weighing >100 g. There were consistent changes in the sign of the slopes above and below the OBS threshold. The intersections of the best-fit lines were within the OBS range for the body size to 3-dimensional home range comparisons. Thus, the data provide some support for the OBS model in strepsirhines. However, no regression model was statistically significant for the taxa below the OBS threshold, which may reflect small sample sizes. Also, no slope differed significantly between taxa above and below the OBS. Significant correlations between body and home range sizes for the complete data sets refute the √-shaped constraint space predicted via the OBS model. [ABSTRACT FROM AUTHOR]

We investigated how greater dwarf lemur (Cheirogaleus major) densities, ambient air temperature, and dendrometrics (tree height and diameter) varied along forest edge-interior gradients in the Vohibola III Classified Forest in SE Madagascar. We also assessed if spatial variations in densities of Cheirogaleus major provide indirect evidence of increased predation pressure in the transition zone between edge and interior forest habitats, i.e., an ecological trap. We conducted diurnal temperature surveys (N = 394) and nocturnal surveys of Cheirogaleus major (N = 182) over 2 yr along 4 1250-m transects that ran perpendicular to the forest edge in Vohibola III. We did not see Cheirogaleus major from May to mid-September, and the highest sighting frequency occurred during October–November. Cheirogaleus major exhibited a negative edge response because densities ranged from low levels in edge habitats to higher levels in the forest interior. After we tested for spatial autocorrelation, edge-related variations in densities of Cheirogaleus major covaried most strongly with tree diameter. Edge responses of Cheirogaleus major may reflect spatial variations in fruit and liana abundance, though data are needed on the precise relationship between tree diameter and food production to confirm the relationship. Edge-related variations in densities of Cheirogaleus major may also provide indirect evidence of an ecological trap. Testing and controlling for spatial autocorrelation should be important components of future studies of primate conservation biology and ecology. [ABSTRACT FROM AUTHOR]

The Fandriana-Marolambo forest corridor is one of the largest (ca. 250,000 ha) and least explored tracts of unprotected forest in southeast Madagascar. Although published range maps show continuous distributions for many lemurs throughout the region, there are few data on lemur community structure in the corridor. We aimed to determine lemur community structure, with its ecological correlates (altitude, agriculture, selective logging, and hunting), in the Fandriana-Marolambo forest corridor. We surveyed 7 sites and sighted 4 nocturnal taxa ( Avahi laniger, Cheirogaleus major, Lepilemur mustelinus, and Microcebus rufus) and 6 diurnal taxa ( Eulemur rubriventer, E. fulvus rufus, E. f. fulvus, Propithecus diadema edwardsi, Hapalemur griseus griseus, and Varecia variegata variegata). Composition of the lemur community was broadly similar to that of nearby protected areas (Ranomafana and Mantadia National Parks). However, we sighted no Hapalemur aureus, H. simus, or Indri indri, and observed Propithecus diadema edwardsi and Varecia variegata variegata at only 1 site each. We sighted an apparent hybrid form of Eulemur fulvus fulvus and E. f. rufus that may represent a new hybrid zone for lemurs. After testing for spatial autocorrelation, lemur diversity correlates negatively with altitude and agricultural intensity. Though the Government of Madagascar is assessing the corridor as a new national park, we suggest conservation plans for local lemurs are complicated by population isolation and lack of data on minimum viable size of the proposed protected area. [ABSTRACT FROM AUTHOR]

I investigated how transect type (trails vs. cut transects) and seasonality influenced density estimates for 5 lemur taxa (Avahi laniger, Cheirogaleus major, Eulemur rubriventer, Hapalemur griseus griseus, and Microcebus rufus) in the Vohibola III Classified Forest in SE Madagascar. I surveyed tree height and diameter and lemur populations from June 1 to December 28, 2004 along 2 1250-m trails local people used and 2 1250-m transects cut parallel to the trails in primary rain forest. Despite dendrometric variations within and between trails and transects, only density estimates of Hapalemur griseus griseus differed significantly by transect type. The spatial variation may be a result of removal by local people of giant bamboo, which is the main food for Hapalemur griseus griseus, along trails. Conversely, seasonality influenced density estimates for Cheirogaleus major, Eulemur rubriventer, Hapalemur griseus griseus, and Microcebus rufus. The temporal variations may be related to seasonal torpor for Cheirogaleus major and increased detection probabilities during periods of fruit exploitation for Eulemur rubriventer, Microcebus rufus, and Hapalemur griseus griseus. Transect type and seasonality did not affect density estimates for Avahi laniger, which may be related to the highly folivorous and low-energy diet of the nocturnal lemur. Researchers surveying lemurs along line transects should be aware that transect selection may influence density estimates for Hapalemur griseus griseus and that seasonality may influence density estimates for Cheirogaleus major, Eulemur rubriventer, Hapalemur griseus griseus, and Microcebus rufus. [ABSTRACT FROM AUTHOR]

The phylogenetic diversity of extant lemurs represents one of the most important but least studied aspects of the conservation biology of primates. The phylogenetic diversity of a species is inversely proportional to the relative number and closeness of its phylogenetic relatives. Phylogenetic diversity can then be used to determine conservation priorities for specific biogeographic regions. Although Malagasy strepsirhines represent the highest phylogenetic diversity among primates at the global level, there are few phylogenetic data on species-specific and regional conservation plans for lemurs in Madagascar. Therefore, in this paper the following questions are addressed for extant lemurs: 1) how does the measure of taxonomic uniqueness used by Mittermeier et at ([1992] Lemurs of Madagascar; Gland, Switzerland: IUCN) equate with an index of phylogenetic diversity, 2) what are the regional conservation priorities based on analyses of phylogenetic diversity in extant lemurs, and 3) what conservation recommendations can be made based on analyses of phylogenetic diversity in lemurs? Taxonomic endemicity standardized weight (TESW) indices of phylogenetic diversity were used to determine the evolutionary component of biodiversity and to prioritize regions for conserving lemur taxa. TESW refers to the standardization of phylogenetic diversity indices for widespread taxa and endemicity of species. The phylogenetic data came from recent genetic studies of Malagasy strepsirhines at the species level. Lemur species were assigned as being either present or absent in six biogeographic regions. TESW indices were combined with data on lemur complementarity and protected areas to assign conservation priorities at the regional level. Although there were no overall differences between taxonomic ranks and phylogenetic rankings, there were significant differences for the top-ranked taxa. The phylogenetic component of lemur diversity is greatest for Daubentonia madagascariensis, Allocebus trichotis, Lepilemur septentrionalis, Indri indri, and Mirza coquereli. Regional conservation priorities are highest for lemurs that range into northeast humid forests and western dry forests. Expansion of existing protected areas in these regions may provide the most rapid method for preserving lemurs. In the long term, new protected areas must be created because there are lemur species that: 1) are not found in existing protected areas, 2) exist only in one or two protected areas, and 3) are still being discovered outside the current network of protected areas. Data on the population dynamics and feeding ecology of phylogenetically important species are needed to ensure that protected areas adequately conserve lemur populations in Madagascar. [ABSTRACT FROM AUTHOR]

Forest edges are dynamic zones characterized by the penetration (to varying depths and intensities) of conditions from the surrounding environment (matrix) into the forest interior. Although edge effects influence many tropical organisms, they have not been studied directly in primates. Edge effects are particularly relevant to lemurs because of the highly fragmented forest landscapes found in Madagascar. In this study, data are presented regarding how the densities of six lemur species (Avahi laniger, Cheirogaleus major, Eulemur rubriventer, Hapalemur griseus griseus, Microcebus rufus, and Propithecus diadema edwardsi) varied between six 500-m interior transects and six 500-m edge transects in the Vohibola III Classified Forest in SE Madagascar. Diurnal (n = 433) and nocturnal (n = 128) lemur surveys were conducted during June–October 2003 and May–November 2004. A. laniger, E. rubriventer, and H. g. griseus exhibited a neutral edge response (no differences in densities between habitats). M. rufus and P. d. edwardsi had a positive edge response (higher densities in edge habitats), which may be related to edge-related variations in food abundance and quality. Positive edge responses by M. rufus and P. d. edwardsi may ultimately be detrimental due to edge-related anthropogenic factors (e.g., hunting by local people). The negative edge response exhibited by C. major (lower densities in edge habitats) may result from heightened ambient temperatures that inhibit torpor in edge habitats. Am. J. Primatol. 68:293–299, 2006. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Edge effects are caused by the penetration of abiotic and biotic conditions from the matrix into forest interiors. Although edge effects influence the biogeography of many tropical organisms, they have not been studied directly in primates. Edge effects are particularly relevant to lemurs due to the loss of 80–90% of forests in Madagascar. In this study, data are presented on how biotic edge effects influenced the distribution and density of lemurs in the Vohibola III Classified Forest in southeastern Madagascar. In total, 415 lemur surveys were conducted during June-October 2003 and May-September 2004 along six 1,250-m transects that ran perpendicular to the forest edge. Data were also collected on lemur food trees along the six transects (density, height, diameter at breast height, area, volume, and distance to forest edge). Four nocturnal species (Avahi laniger, Cheirogaleus major, Lepilemur microdon, and Microcebus rufus) and four diurnal species (Eulemur rubriventer, Eulemur fulvus rufus, Hapalemur grisesus griseus, and Propithecus diadema edwardsi) were sighted during surveys. Regression analyses of lemur densities as a function of distance to forest edge provided edge tolerances for A. laniger (edge-tolerant), M. rufus (edge-tolerant), E. rubriventer (edge-tolerant or omnipresent), and H. g. griseus (omnipresent). The density and distribution of M. rufus and their foods trees were correlated. Edge-related variations in food quality and predation pressures may also be influencing lemurs in Vohibola III. Tolerance for edge effects may explain, in part, how lemurs have survived extreme habitat loss and forest fragmentation in southeastern Madagascar. [ABSTRACT FROM AUTHOR]

This paper describes the results of field surveys for two Endangered lemurs, Mime-Edward's sifaka Propithecus diadema edwardsi and the black and white ruffed lemur Varecia variegata variegata, in the unprotected Fandriana-Marolambo forest corridor in south-east Madagascar. Published range maps show P. d. edwardsi and V. v. variegata present in the corridor, although few surveys have been conducted in this area. A total of 292.9 km of surveys were conducted at eight sites in the corridor but P. d. edwardsi and V. v. variegata were each located at only one site. Absence of these species at other sites may be the combined result of altitudinal and anthropogenic effects. Conservation plans for P. d. edwardsi and V. v. variegata are complicated because gaps in forest cover prevent dispersal of conspecifics from nearby protected areas. Conservation authorities should be cautious in using range maps based on the presumed distribution of lemur species. [ABSTRACT FROM AUTHOR]

Ecogeographic size variations have been documented in some but not all sifakas. Few morphometric or body weight data have been available for two critically endangered subspecies of diademed sifakas: Perrier's sifakas (Propithecus diadema perrieri) and silky sifakas (Propithecus diadema candidus). The objectives of our study were to determine size variations in sifakas and if these variations are related to resource quality and/or resource seasonality. P. d. perrieri and P. d. candidus were captured, weighed, and measured in northern Madagascar. Body weights and morphometrics were compared with other subspecies of diademed sifakas and indris (Indri indri). Differences in body weights and morphometrics between taxa are particularly pronounced for P. d. perrieri compared to P. d. diadema, P. d. edwardsi, and I. indri. Most morphometrics varied in comparisons between P. d. candidus and the other Indriidae (P. d. diadema, P. d. edwardsi, and I. indri). Average body size in sifakas is positively correlated with annual rainfall and negatively correlated with length of dry season. Sifaka body size is not correlated with protein-to-fiber ratios. Thus, size variations in sifakas are related to resource seasonality rather than resource quality. The relationships between the temporal availability of food resources and sifaka body size reflect complex and regionally varying causalities. Detailed, longitudinal information on the ecological factors underlying food selection and nutrient requirements in sifakas are needed to determine the relationship between ecogeographic variables and body size in sifakas. [ABSTRACT FROM AUTHOR]

Some lemur species range into only one habitat type, whereas others range into a variety of habitats. Because plant community structure can differ between habitats, dietary patterns may vary for conspecific groups of primates that range into more than one type of habitat. The goal of our study was to determine how habitat variation influences dietary patterns in Perrier's sifakas (Propithecus diadema perrieri ) that range into both dry and riparian forests in northern Madagascar. We collected 542 hr of data on the behavior and diet of two groups of P.d. perrieri from 7 June to 4 August 1998 at Camp Antobiratsy in Analamera Special Reserve, Madagascar. We computed indices of dietary diversity for each group and dietary/plant species similarity between groups. P.d. perrieri in group 1 fed predominantly in dry forest (72.7% of feeding records, n=660), whereas those in group 2 fed most often in riparian forest (73.7% of feeding records, n=666). The index of dietary similarity (0.986) was significantly higher than the index of plant species similarity (0.767). Although the P.d. perrieri in the two study groups fed predominantly in different forest habitats, they ate similar food items in very comparable proportions (but not from the same plant species). However, based on habitat availability measures, neither group fed where they were expected to feed. Am. J. Primatol. 62:115-122, 2004. © 2004 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Studies of primate community structure increase our understanding of behavior, adaptation, and evolution. However, there are few biogeographic data on specific composition and association patterns in primate communities. I conducted a biogeographic analysis of the community structure of primate species at 16 sites in Guyana. I used data from 1725 km of line-transect censuses to determine specific composition and association patterns of 220 primate groups . Of the 18 polyspecific groups, 94.1% (N = 16) included squirrel monkeys. There was an overall trend towards positive specific associations among Guyanese primates. The only species that exhibited a negative pattern of interspecific associations were brown and wedge-capped capuchins. The sighting rate for wedge-capped capuchins at sympatric sites was particularly depressed compared to that for brown capuchins. Low plant productivity in Guyanese forests may reduce the diversity of feeding niches and result in a low incidence of polyspecific associations and scramble competition between wedge-capped and brown capuchins. [ABSTRACT FROM AUTHOR]

Reports on a preliminary survey of Cacajao melanocephalus melanocephalus in Southern Amazonas, Venezuela, to update information on their distribution and select a site for a longitudinal study. Threats to South American primate populations; Presence of illegal gold miners from Brazil; Population of C. m. melanocephalus in the upper Rio Orinoco-Brazo Casiquiare basin.

Presents data from a study on the relationship between climate and seasonal reproduction in the Florida rhesus macaques colonies, Raccoon Key and Key Lois. Factors that influence reproductive seasonality; Annual distribution of conception and birth; Climatic conditions in the study sites; Birth season asynchrony.

Rhesus macaques on Key Lois Island were observed drinking seawater that flowed into four holes they had excavated in the sand. Data were gathered to determine the salinity (TDS) and pH levels of the water and which animals were using the holes. Average TDS level (4,506.8 ± 1,750.8), but not pH (8.1 ± .30) level, of water from the holes differed from the surrounding seawater (TDS = 29,000, pH = 8.0). There were significant variations in TDS and pH levels of water between holes. A total of 249 drinking and 11 digging bouts were observed. Adult females drank and dug most often (46.9% of total bouts). Of the 260 total drinking and digging bouts, 76.1% (N = 198) were concentrated at one hole. This hole had the lowest average TDS level (3,714.2 ± 1,504.4) and one of the highest average pH levels (8.1 ± .29). Age/sex class differences in drinking bout frequencies may have been due to differential social status. We suggest that the holes were excavated to overcome a temporary shortage of provisioned water. [ABSTRACT FROM AUTHOR]

Wildlife‐vehicle collisions can be a significant cause of mortality for animals with ranges that overlap roads. Not all species are equally affected by roads and thus conservation practitioners need empirical data to determine appropriate mitigation measures. However, there is a lack of data on how tropical animals, in particular those on the island of Madagascar, are affected by roads and vehicular mortality. In order to fill in this gap in the literature we investigated the ecological and spatial factors influencing roadkill observations along Route National 4 in Ankarafantsika National Park, Madagascar. We observed 80 cases of roadkill along the highway belonging to at least 13 species, including the first published record of a lemur as roadkill. We also found that the density of roadkill was lower in the area between two speedbumps, suggesting these are an effective measure to mitigate wildlife‐vehicle collisions. These results showcase that even within protected areas of Madagascar animals are at risk of vehicular mortality but mitigation measures are possible. Given the high rates of endemicity coupled with vulnerability to extinction of many Malagasy fauna there is an urgent need for more research on road ecology in Madagascar. [ABSTRACT FROM AUTHOR]

We used species‐area relationships (SARs) to investigate the effects of habitat loss on lemur biogeography. We measured species richness via visual surveys on line transects within 42 fragments of dry deciduous forest at the Ambanjabe field site in Ankarafantsika National Park, Madagascar. We measured human disturbance and habitat characteristics within 38 of the 42 fragments. We measured the distance between each fragment and the nearest settlement, continuous forest, and nearest neighboring fragment. We fit 10 candidate SAR models to the data using nonlinear least squares regression and compared them using Akaike's Information Criterion (AIC). To determine how habitat characteristics, as well as area, influenced species richness, we ran a hierarchical partitioning procedure to select which variables to include in generalized additive models (GAMs) and compared them using AIC. Contrary to expectations, we found that lemurs form convex SARs, without a "small island effect", and with the power model being the most likely SAR model. Although we found that four variables (area, survey effort, and total human disturbance, and mean tree height) independently contributed greater than 10% of the variation in lemur species richness, only area was included in the most likely model. We suggest that the power model was the most likely SAR model and our inability to detect a "small island effect" are the result of Microcebus spp. being edge tolerant and capable of dispersing through matrix, scale issues in the study design, and low γ‐diversity in the landscape. However, more study is needed to determine what role human disturbance plays in influencing species richness in lemurs. [ABSTRACT FROM AUTHOR]

Studies on the impact of habitat loss on species occurrence consistently find that the amount of habitat (measured as patch area) is a major determinant of species occurrence at a patch‐level. However, patch‐level research may fail to detect important patterns and processes only observable at a landscape‐level. A landscape‐level approach that incorporates species‐specific scale responses is needed to better understand what drives species occurrence. Our aim was to determine the landscape‐level scale of effect of habitat amount on the occurrence of three species of nocturnal lemurs (Cheirogaleus medius, Microcebus murinus, and M. ravelobensis). We surveyed line transects to determine the occurrence of three lemur species within a fragmented landscape of deciduous dry forest and anthropogenic grassland in northwestern Madagascar. To determine the scale of effect of habitat loss on lemur occurrence, we compared logistic regression models of occurrence against habitat amount among eight different landscape scales using Akaike's Information Criterion values. We found differing scale responses among the lemurs in our study. Occurrence of C. medius responded to habitat amount at scales between 0.5–4 ha, M. murinus at scales between 1 and 4 ha and M. ravelobensis at scales between 0.125 and 4 ha. We suggest that the scale of effect for C. medius is mediated by their ability to hibernate. A relatively lower scale‐response for Microcebus spp. likely reflect their omnivorous diet, small habitat requirements, and limited dispersal ability. Differences in scale responses between M. murinus and M. ravelobensis are likely a result of differing dispersal ability and responses to edge effects between these species. Our study is among the first on lemurs to show the value of a landscape‐level approach when assessing the effects of habitat loss on species occurrence. Research Highlights: Closely related species show differing landscape‐level scale of effect of habitat loss on occurrence.Differing scale responses to habitat amount may relate to home range size and dispersal ability.Small scale of effect of habitat amount on the occurrence of Cheirogaleus medius may be mediated by their ability to hibernate. [ABSTRACT FROM AUTHOR]

Although roads are often assumed to be barriers to the dispersal of arboreal species, there has been little empirical testing of this assumption. If arboreal animals are unable to cross roads, population subdivision may occur, or resources may become inaccessible. We tested the hypothesis that Route Nationale 4 (RN4), a paved highway, was a barrier to movement and dispersal of the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, in north-west Madagascar. During June–August 2015 we conducted a capture–mark–recapture study at three sites: two adjacent to RN4 and one within intact forest without a potential barrier. During 2,294 trap nights we captured 120 golden-brown mouse lemurs 1,032 times. In roadside habitats we captured significantly more males than females, whereas the opposite was the case in interior forest habitat. We detected eighteen crossings of highway transects by nine individuals; however, all potential dispersal events involved males. In roadside habitat, movement was significantly inhibited in both males and females. We present some of the first data on the effects of roads on movement patterns in arboreal Malagasy mammals, showing species- and sex-biased effects of roads as dispersal barriers. Our findings indicate that roads may not be complete barriers to dispersal in lemurs. We recommend that conservation managers and scientists examine explicitly the effects of roads and natural arboreal bridges in Madagascar in future studies. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation are of concern to conservation biologists worldwide. However, not all organisms are affected equally by these processes; thus, it is important to study the effects of living in fragmented habitats on species that differ in lifestyle and habitat requirements. In this study, we examined the dispersal and connectivity patterns of rodents, one endemic (Eliurus myoxinus) and one invasive (Rattus rattus), in two landscapes containing forest fragments and adjacent continuous forest patches in northwestern Madagascar. We generated genetic (RADseq) data for 66 E. myoxinus and 81 R. rattus individuals to evaluate differences in genetic diversity as well as inbreeding and connectivity in two landscapes. We found higher levels of inbreeding and lower levels of genetic diversity in E. myoxinus compared with R. rattus. We observed related dyads both within and between habitat patches and positive spatial autocorrelation at lower distance classes for both species, with a stronger pattern of spatial autocorrelation in R. rattus. Across each site, we identified contrasting migration rates for each species, but these did not correspond to habitat–matrix dichotomies. The relatively low genetic diversity in the endemic E. myoxinus suggests ecological constraints that require further investigation. [ABSTRACT FROM AUTHOR]

It is important to understand how sympatric congeners can co-occur within the same landscapes to better understand niche differentiation and how each species respond to habitat modification. We compiled previously published, long-term data from several studies on encounter rates of two sympatric mouse lemurs (Microcebus ravelobensis and M. murinus) in different survey sites (surveyed portions of continuous forest and individual fragments) using trapping (N = 16 sites; 42 samples) and visual (N = 42 sites; 73 samples) survey methods in Ankarafantsika National Park, Madagascar (total N = 58 sites; 115 samples). A sample reflects multiple surveys, visual, and/or trapping (N = 2–21) along a line-transect and/or trapline within 1 year. We found higher encounter rates of M. ravelobensis and M. murinus in continuous forests and fragmented forests, respectively. Contrary to studies conducted at a smaller scale, yearly encounter rates for M. ravelobensis were negatively associated with rainfall but were positively associated with rainfall for M. murinus. Like previous studies, we found a negative correlation in encounter rates between M. ravelobensis and M. murinus in continuous forests. However, in fragmented forests there was a significant positive relationship between the two species. Our data suggest that M. ravelobensis preferred continuous forest habitat, whereas the congeneric M. murinus preferred fragmented forest habitat. Such results are likely related to species-specific ecological requirements: whereas the continuous forest has conditions that M. ravelobensis finds preferential (i.e., wetter, taller, and denser forests), the forest fragments are drier, habitat that is preferred by M. murinus. [ABSTRACT FROM AUTHOR]

Edge effects represent an inevitable and important consequence of habitat loss and fragmentation. These effects include changes in microclimate, solar radiation, or temperature. Such abiotic effects can, in turn, impact biotic factors. They can have a substantial impact on species, communities, and ecosystems. Here we examine clinal variations in stable carbon and nitrogen isotope values for trees along an edge-interior gradient in the dry deciduous forest at Ankarafantsika National Park. We predicted that soil respiration and differences in solar irradiance would result in stratified δ13C values where leaves collected close to the forest floor would have lower δ13C values than those growing higher up in the canopy. We also anticipated that plants growing at the savannah-forest boundary would have higher δ13C and δ15N values than plants growing in the forest interior. As expected, we detected a small but significant canopy effect. Leaves growing below 2 m from the forest floor exhibit δ13C values that are, on average, 1.1‰ lower than those growing above this threshold. We did not, however, find any relationship between foliar δ13C and distance from the edge. Unpredictably, we detected a striking positive relationship between foliar δ15N values and increasing distance into the forest interior. Variability in physiology among species, anthropogenic influence, organic input, and rooting depth cannot adequately explain this trend. Instead, this unexpected relationship most likely reflects decreasing nutrient or water availability, or a shift in N-sources with increasing distance from the savannah. Unlike most forest communities, the trees at Ampijoroa are growing in nutrient-limited sands. In addition to being nutrient poor, these well-drained soils likely decrease the amount of soil water available to forest vegetation. Continued research on plant responses to edge effects will improve our understanding of the conservation biology of forest ecosystems in Madagascar. [ABSTRACT FROM AUTHOR]

We tested four major hypotheses on the ecological aspects of body mass variation in extant Malagasy strepsirrhines: thermoregulation, resource seasonality/scarcity, resource quality, and primary productivity. These biogeographic hypotheses focus on the ecological aspects of body mass variation, largely ignoring the role of phylogeny for explaining body mass variation within lineages. We tested the independent effects of climate and resource-related variables on variation in body mass among Malagasy primates using recently developed comparative methods that account for phylogenetic history and spatial autocorrelation. We extracted data on lemur body mass and climate variables for a total of 43 species from 39 sites. Climatic data were obtained from the WorldClim database, which is based on climate data from weather stations compiled around the world. Using generalized linear models that incorporate parameters to account for phylogenetic and spatial autocorrelation, we found that diet and climate variables were weak predictors of lemur body mass. Moreover, there was a strong phylogenetic effect relative to the effects of space on lemur body mass in all models. Thus, we failed to find support for any of the four hypotheses on patterns of geography and body mass in extant strepsirrhines. Our results indicate that body mass has been conserved since early in the evolutionary history of each genus, while species diversified into different environmental niches. Our findings are in contrast to some previous studies that have suggested resource and climate related effects on body mass, though these studies have examined this question at different taxonomic and/or geographic scales. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation are major ecological forces threatening animal communities across the globe. These issues are especially true in Madagascar, where forest loss is ongoing. We examined the effects of forest fragmentation on the distribution and abundance of sympatric, endemic gray, and golden‐brown mouse lemurs (Microcebus murinus and Microcebus ravelobensis), the endemic western tuft‐tailed rat (Eliurus myoxinus), and the invasive black rat (Rattus rattus) in two regions in northwestern Madagascar. We used systematic capture procedures in 40 forest fragments and four continuous forest sites which differed in size, shape, and degree of isolation. With a trapping effort of 11,567 trap nights during two dry seasons (2017–2018), we captured 929 individuals (432 M. ravelobensis, 196 M. murinus, 116 E. myoxinus, and 185 R. rattus). We examined the influence of study region, forest type (fragment vs. continuous), forest size, forest shape, the proportion of 50‐m forest edge and distance to continuous forest on the abundance and interaction of the four species. Responses to fragmentation differed strongly between species, but no interaction could be detected between the abundance of the different species. Thus competition within and between native and invasive species may not be regulating abundances in these regions. On the contrary, the abundance of M. ravelobensis and E. myoxinus differed significantly between study regions and was negatively affected by fragmentation. In contrast, there was no evidence of an impact of fragmentation on the abundance of M. murinus. Finally, the invasive R. rattus responded positively to the increasing distance to the continuous forest. In conclusion, the response of small Malagasy mammals to forest fragmentation varies largely between species, and fragmentation effects need to be examined at a species‐specific level to fully understand their ecological dynamics and complexity. Research Highlights: Habitat fragmentation affects the abundance of mouse lemurs and rodents differently.Endangered Microcebus ravelobensis and Eliurus myoxinus are more sensitive to fragmentation than Microcebus murinus and Rattus rattus.There was no evidence for interspecific competition. [ABSTRACT FROM AUTHOR]

In contrast to the majority of primates, which exhibit dedicated diurnality or nocturnality, all species of Eulemur are cathemeral. Colour vision, in particular, is strongly affected by the spectral composition and intensity of ambient light, and the impact of activity period on the evolution of primate colour vision is actively debated., We studied three groups of wild brown lemurs ( Eulemur fulvus) in Ankarafantsika National Park, Madagascar, over a 1-year span. We also used non-invasive faecal DNA collection and analysis to study the opsin genes underlying the colour vision of 24 individuals. We quantified the colour and brightness of dietary fruits and modelled the chromaticity and discriminability of food objects to different visual phenotypes under daylight, twilight and moonlight conditions., We found that E. fulvus possesses routine dichromacy, unlike its congener E. flavifrons, for which polymorphic trichromacy has been reported. Our models suggest that dichromacy is well suited to the foraging ecology of E. fulvus. The performance of modelled dichromats and trichromats is comparable under nocturnal illuminants, and the luminance values of most diet items are detectable across light conditions. The trichromatic phenotype demonstrates a modest advantage under daylight conditions., Our results, taken together with reports of polymorphic trichromacy in E. flavifrons, suggest functional ecological variation in the visual system of the genus Eulemur. Interspecific phenotypic variation in the colour vision of a genus is both unexpected and instructive., Ecological differences between species of Eulemur could reveal thresholds for the origins of polymorphic trichromacy, which preceded the evolution of routine trichromatic vision in humans and other primates. [ABSTRACT FROM AUTHOR]

Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by mouse lemurs. We show that both fruit colour and odour significantly predict fruit consumption and seed dispersal by Microcebus ravelobensis and M. murinus. Our study is the first to quantify and examine the role of bimodal fruit signals on seed dispersal in light of the sensory abilities of the disperser. [ABSTRACT FROM AUTHOR]

Aim Phylogenetics has an important role in conservation biogeography. However, there are few data on the phylogenetic diversity of African primates. The phylogenetic diversity (PD) of a species is a measure of its taxonomic distinctness and can be estimated by looking at the phylogenetic relationships among taxa. Species-specific metrics on PD can then be used to determine conservation priorities at various biogeographical scales. We used PD metrics to rank 55 African primate species according to their conservation priorities at the country level and within six African biogeographical regions. We also addressed the following question: are there differences in conservation rankings between the IUCN Red List and our PD metrics? Location Africa. Methods We created a consensus phylogeny for all African primate clades based on genetic studies. Analyses of species distributions were determined using presence /absence scores at two levels: country and biogeographical region. A node-based method that standardizes for widespread taxa and endemicity was used to calculate PD indices. Hierarchical cluster analysis was used to convert one of the standardized, phylogenetic indices into three clusters that could be ranked and compared with the main IUCN conservation rankings of endangered, vulnerable, and lower risk. Results At the country and region levels, the top-priority species in terms of PD are Pan paniscus, Macaca sylvanus, Arctocebus calabarensis, Gorilla beringei, Arctocebus aureus, Allenopithecus nigroviridis, Gorilla gorilla, Procolobus verus, Cercopithecus solatus, Cercocebus galeritus, Colobus angolensis, Theropithecus gelada, Galagoides zanzibaricus, Galagoides granti, and Procolobus (Piliocolobus) badius. Geographic rankings were highest for the Democratic Republic of the Congo (country level) and Central Africa (region level). Although there were no overall differences between IUCN conservation ranks and the PD rankings, there were significant differences between the two systems for vulnerable and endangered primate taxa. Main conclusions There are few ecological and behavioural data on populations of some of the African primates that represent the highest levels of phylogenetic diversity. Studies of primate taxa with high PD rankings should focus on identifying sites suitable for intensive studies of population densities, feeding ecology, and reproductive behaviour. We suggest that PD metrics can serve as an important, complementary data set in the IUCN ranking system for primates. [ABSTRACT FROM AUTHOR]