A combined research agenda towards integrated conservation and development for Madagascar

Better integration of social and natural science activities seems to be the key to improve the efficiency of conservation and development. While there is no recipe for success, this paper argues that conservation has to pay for itself if it wants to be anchored in present day societies. In systems where humans depend largely on subsistence activities, economic benefits from conservation must outweigh the benefits from increasing these activities. Coming from a natural science perspective, this paper proposes some activities that could improve the basis for decision making and contribute to the long term integration of sustainable conservation and development. It is argued that experiences from various projects must be evaluated and be accessible; data should be stored in a central database that can be used to develop future programs; restoration of various sorts providing direct income for the local human populations (including gardens, native and exotic tree plantations with valuable species) should be a priority; and natural science projects should add analyses of processes to the present preponderance of describing patterns. All these activities should result in integrated action to maintain natural biodiversity as a key component to maintain and improve local livelihoods. KEYWORDS: Restoration, database management, ecosystem function, ecosystem process

Effects of fencing on forage biomass and quality through livestock exclusion from a protected area in the southern Kalahari

The substitution of wild herbivores by livestock has led to substantial degradation of many southern African grazing systems. As a result, bush and shrub encroachment has led to a reduction of grasslands, invasion of thorn shrubs, reduced carrying capacity of range land, and desertification. These changes often raise socio-economic challenges for rural communities in arid and semi-arid regions, as previously profitable areas may become no longer economically viable. This study aims to compare biomass and key chemical characteristics of grassy vegetation between sites experiencing low vs. high grazing pressures. Furthermore, we estimate the recovery time needed for pasture in heavily grazed areas to reach properties of similar sites under low grazing pressure. In heavily grazed areas, grass was of higher quality than in areas with low grazing pressure, as the remaining or re-growing grass contains higher percentages of protein and lower concentrations of fiber. However, as heavy grazing led to reduced grass biomass, the absolute amount of protein available per unit area was lower in areas with high compared to areas with low grazing pressure. Furthermore, at the heavily grazed area we recorded a high proportion of unpalatable plant species. The exclusion of livestock through fencing resulted in a rapid increase of grass biomass and therefore higher amounts of fibre, protein and hemicellulose contents per unit area after one wet season, whereas the chemical concentrations of plant compounds changed remarkably little after elimination of livestock grazing pressure. In areas where cattle substitute wild-ranging herbivores we recommend livestock managers consider transitioning to sustainable grazing systems through grazing rotation, diversification of herbivore species, and reduction in stocking rates. This would secure sustainable livestock-based livelihoods while avoiding permanent rangeland degradation due to bush encroachment and desertification

Nutritional Characteristics of Wild and Cultivated Foods for Chimpanzees (Pan troglodytes) in Agricultural Landscapes

Primate habitats are being transformed by human activities such as agriculture. Many wild primates include cultivated foods (crops) in their diets, calling for an improved understanding of the costs and benefits of crop feeding. We measured the macronutrient and antifeedant content of 44 wild and 21 crop foods eaten by chimpanzees (Pan troglodytes schweinfurthii) in a mosaic habitat at Bulindi, Uganda, to evaluate the common assertion that crops offer high nutritional returns compared to wild forage for primates. In addition, we analyzed 13 crops not eaten at Bulindi but that are consumed by chimpanzees elsewhere to assess whether nutritional aspects explain why chimpanzees in Bulindi ignored them. Our analysis of their wild plant diet (fruit, leaves, and pith) corresponds with previous chemical analyses of primate plant foods. Compared to wild food equivalents, crops eaten by the chimpanzees contained higher levels of digestible carbohydrates (mainly sugars) coupled with lower amounts of insoluble fiber and antifeedants. Cultivated fruits were relatively nutritious throughout the ripening process. Our data support the assumption that eating cultivated foods confers energetic advantages for primates, although crops in our sample were low in protein and lipids compared to some wild foods. We found little evidence that crops ignored by the chimpanzees were less nutritious than those that they did eat. Nonnutritional factors, e.g., similarity to wild foods, probably also influence crop selection. Whether cultivated habitats can support threatened but flexible primates such as chimpanzees in the long term hinges on local people’s willingness to share their landscape and resources with them

Small-scale coexistence of two mouse lemur species (Microcebus berthae and M. murinus) within a homogeneous competitive environment

Understanding the co-occurrence of ecologically similar species remains a puzzling issue in community ecology. The species-rich mouse lemurs (Microcebus spec.) are distributed over nearly all remaining forest areas of Madagascar with a high variability in species distribution patterns. Locally, many congeneric species pairs seem to co-occur, but only little detailed information on spatial patterns is available. Here, we present the results of an intensive capture–mark–recapture study of sympatric Microcebus berthae and M. murinus populations that revealed small-scale mutual spatial exclusion. Nearest neighbour analysis indicated a spatial aggregation in Microcebus murinus but not in M. berthae. Although the diet of both species differed in proportions of food categories, they used the same food sources and had high feeding niche overlap. Also, forest structure related to the spatial distribution of main food sources did not explain spatial segregation because parts used by each species exclusively did not differ in density of trees, dead wood and lianas. We propose that life history trade-offs that result in species aggregation and a relative increase in the strength of intra-specific over inter-specific competition best explain the observed pattern of co-occurrence of ecologically similar congeneric Microcebus species

Geogenetic patterns in mouse lemurs (genus Microcebus) reveal the ghosts of Madagascar's forests past.

Phylogeographic analysis can be described as the study of the geological and climatological processes that have produced contemporary geographic distributions of populations and species. Here, we attempt to understand how the dynamic process of landscape change on Madagascar has shaped the distribution of a targeted clade of mouse lemurs (genus Microcebus) and, conversely, how phylogenetic and population genetic patterns in these small primates can reciprocally advance our understanding of Madagascar's prehuman environment. The degree to which human activity has impacted the natural plant communities of Madagascar is of critical and enduring interest. Today, the eastern rainforests are separated from the dry deciduous forests of the west by a large expanse of presumed anthropogenic grassland savanna, dominated by the Family Poaceae, that blankets most of the Central Highlands. Although there is firm consensus that anthropogenic activities have transformed the original vegetation through agricultural and pastoral practices, the degree to which closed-canopy forest extended from the east to the west remains debated. Phylogenetic and population genetic patterns in a five-species clade of mouse lemurs suggest that longitudinal dispersal across the island was readily achieved throughout the Pleistocene, apparently ending at ∼55 ka. By examining patterns of both inter- and intraspecific genetic diversity in mouse lemur species found in the eastern, western, and Central Highland zones, we conclude that the natural environment of the Central Highlands would have been mosaic, consisting of a matrix of wooded savanna that formed a transitional zone between the extremes of humid eastern and dry western forest types

Better Few than Hungry: Flexible Feeding Ecology of Collared Lemurs Eulemur collaris in Littoral Forest Fragments

Frugivorous primates are known to encounter many problems to cope with habitat degradation, due to the fluctuating spatial and temporal distribution of their food resources. Since lemur communities evolved strategies to deal with periods of food scarcity, these primates are expected to be naturally adapted to fluctuating ecological conditions and to tolerate a certain degree of habitat changes. However, behavioral and ecological strategies adopted by frugivorous lemurs to survive in secondary habitats have been little investigated. Here, we compared the behavioral ecology of collared lemurs (Eulemur collaris) in a degraded fragment of littoral forest of south-east Madagascar, Mandena, with that of their conspecifics in a more intact habitat, Sainte Luce.Lemur groups in Mandena and in Sainte Luce were censused in 2004/2007 and in 2000, respectively. Data were collected via instantaneous sampling on five lemur groups totaling 1,698 observation hours. The Shannon index was used to determine dietary diversity and nutritional analyses were conducted to assess food quality. All feeding trees were identified and measured, and ranging areas determined via the minimum convex polygon. In the degraded area lemurs were able to modify several aspects of their feeding strategies by decreasing group size and by increasing feeding time, ranging areas, and number of feeding trees. The above strategies were apparently able to counteract a clear reduction in both food quality and size of feeding trees.Our findings indicate that collared lemurs in littoral forest fragments modified their behavior to cope with the pressures of fluctuating resource availability. The observed flexibility is likely to be an adaptation to Malagasy rainforests, which are known to undergo periods of fruit scarcity and low productivity. These results should be carefully considered when relocating lemurs or when selecting suitable areas for their conservation

Long-term field studies of lemurs, lorises, and tarsiers

Lemurs, lorises, and tarsiers are socially and ecologically diverse primates that include some of the most endangered mammals. We review results of long-term studies of 15 lemur species from 7 sites in Madagascar and 1 species each of loris and tarsier in Indonesia. We emphasize that the existence of long-term study populations is a crucial prerequisite for planning and conducting shorter studies on specific topics, as exemplified by various ecophysiological studies of lemurs. Extended studies of known individuals have revealed variation in social organization within and between ecologically similar species. Even for these primates with relatively fast life histories, it required more than a decade of paternity data to characterize male reproductive skew. The long-term consequences of female rank on reproductive success remain poorly known, however. Long-term monitoring of known individuals is the only method to obtain data on life-history adaptations, which appear to be shaped by predation in the species covered here; long-term studies are also needed for addressing particular questions in community ecology. The mere presence of long-term projects has a positive effect on the protection of study sites, and they generate unique data that are fundamental to conservation measures, such as close monitoring of populations. Los lémures, lorises y tarseros son grupos de primates, muy diversos social y ecológicamente, que incluyen algunas de las especies de mamíferos más amenazadas. Se revisaron los resultados de estudios a largo plazo de 15 especies de lémures en 7 áreas de estudio en Madagascar y una especie de loris y otra de tarsero, en Indonesia. Se resalta la importancia de las áreas de estudio a largo plazo como prerrequisito esencial para planear y llevar a cabo estudios de menor duración sobre temas especificos, como lo ejemplifican varios estudios eco-fisiológicos en lemurs. Estudios a largo plazo de individuos conocidos, han revelado variacion en la organizacion social dentro y entre especies ecologicamente similares. Incluso en estos primates, con un ciclo de vida relativamente corto, se necesita recopilar más de una década de datos de paternidad para determinar el sesgo reproductivo de los machos. Sin embargo, aún se sabe poco de las consecuencias a largo plazo que la posición de las hembras en la jerarquía social puede tener en su éxito reproductivo. El monitoreo a largo plazo de individuos conocidos es el unico metodo para obtener datos sobre adaptaciones en su history natural, las cuales aparentemente son moduladas en function de la predacion a las especies estudiadas en este trabajo. Estos estudios a largo plazo son tambien necesarios para afrontar temas específicos sobre la ecología de estas comunidades. La simple presencia de proyectos a largo plazo tienen un efecto positive en la proteccion de los lugares de studio, como asi tambien generan datos unicos que son fundamentals para apoyar medidas de conservacion tales como el monitoreo de poblaciones

Low levels of fruit nitrogen as drivers for the evolution of Madagascar’s primate communities

The uneven representation of frugivorous mammals and birds across tropical regions – high in the New World, low in Madagascar and intermediate in Africa and Asia – represents a long-standing enigma in ecology. Several hypotheses have been proposed to explain these differences but the ultimate drivers remain unclear. Here, we tested the hypothesis that fruits in Madagascar contain insufficient nitrogen to meet primate metabolic requirements, thus constraining the evolution of frugivory. We performed a global analysis of nitrogen in fruits consumed by primates, as collated from 79 studies. Our results showed that average frugivory among lemur communities was lower compared to New World and Asian-African primate communities. Fruits in Madagascar contain lower average nitrogen than those in the New World and Old World. Nitrogen content in the overall diets of primate species did not differ significantly between major taxonomic radiations. There is no relationship between fruit protein and the degree of frugivory among primates either globally or within regions, with the exception of Madagascar. This suggests that low protein availability in fruits influences current lemur communities to select for protein from other sources, whereas in the New World and Old World other factors are more significant in shaping primate communities

The Importance of Protein in Leaf Selection of Folivorous Primates

Protein limitation has been considered a key factor in hypotheses on the evolution of life history and animal communities, suggesting that animals should prioritize protein in their food choice. This contrasts with the limited support that food selection studies have provided for such a priority in nonhuman primates, particularly for folivores. Here, we suggest that this discrepancy can be resolved if folivores only need to select for high protein leaves when average protein concentration in the habitat is low. To test the prediction, we applied meta-analyses to analyze published and unpublished results of food selection for protein and fiber concentrations from 24 studies (some with multiple species) of folivorous primates. To counter potential methodological flaws, we differentiated between methods analyzing total nitrogen and soluble protein concentrations. We used a meta-analysis to test for the effect of protein on food selection by primates and found a significant effect of soluble protein concentrations, but a non-significant effect for total nitrogen. Furthermore, selection for soluble protein was reinforced in forests where protein was less available. Selection for low fiber content was significant but unrelated to the fiber concentrations in representative leaf samples of a given forest. There was no relationship (either negative or positive) between the concentration of protein and fiber in the food or in representative samples of leaves. Overall our study suggests that protein selection is influenced by the protein availability in the environment, explaining the sometimes contradictory results in previous studies on protein selectio