Annette Hladik

Food intake and Dietary Overlap in Native Lemur catta and Propithecus verreauxi and Introduced Eulemur fulvus at Berenty, Southern Madagascar

The introduction of Eulemur fulvus in 1975 into the Berenty Reserve and their recent attainment of population densities comparable to those of Lemur catta led us to analyze food partitioning among the 3 large prosimian species in the gallery forest. We assessed the diets of ring-tailed lemurs (Lemur catta), brown lemurs (Eulemur fulvus) and sifakas (Propithecus verreauxi) from food intake measurements during 3 successive short-term studies. All species exhibited marked seasonal changes in their major food categories. Dietary overlap was very high between ring-tailed lemurs and brown lemurs during 2 of 3 seasons, including the middle of the dry season. During the latter period, Eulemur appeared to compensate for a low quality diet by increasing the amount of food eaten. In contrast, Lemur fed on lower amounts of food and seemed more efficient at coping with fibrous plant materials. There is low dietary overlap of Lemur catta and Eulemur fulvus versus Propithecus, which exhibit by far the highest dietary diversity of the 3 species. We discuss sustainable coexistence among them, based on respective dietary adaptations and potential for dietary flexibility.

Diet, Nutritional Ecology, and Birth Season of Eulemur macaco in an Anthropogenic Forest in Madagascar

We investigated the feeding ecology of Eulemur macaco macaco in an old coastal secondary forest of northwestern Madagascar. We analyzed whether the local combination of introduced and native plant species could provide viable anthropic conditions for sustaining the black lemurs. Fruits (79 spp.) dominated the annual diet (>104 species from 50 families via observations ad libitum and use of a feeding frequency methods). Records from the early dry (mating) and late dry (birth) seasons show that a few major fruit species are staples in conjunction with a variety of other plant items in much lower proportions. We further estimated daily food intake and analyzed nutrient/antinutrient content in the diet during the birth season to evaluate the possibility that black lemurs undergo nutritional stress. They exhibited a high-energy input/low energy output foraging strategy then and had limited use of alternative resources such as leaves throughout the study period. We conclude that the potential for feeding flexibility is low because specialization on fruit results in protein requirements being achieved probably by a narrow margin. We hypothesize that patchy distribution of preferred cash-crop plants and indigenous species currently has a major limiting effect on population size through feeding competition.

Taste Discrimination in Lemurs and Other Primates, and the Relationships to Distribution of Plant Allelochemicals in Different Habitats of Madagascar

This chapter deals with the adaptation of taste responses of lemurs and other primates to different environments, in relation to primary and secondary compounds in potential foodstuffs. Emphasis is placed on the relationship between taste sensibility to sugars and energy expenditure across species. In the most specialized species, the adaptive trends are inferred according to the importance of the deviation from such allometric relationship. The signification of sugar mimics present in some fruits is discussed in terms of coevolution of plants and tasting ability of primates, that, for lemurs, parallels that of platyrrhine monkeys. Taste responses towards other tastants such as sodium chloride are examined in relation to potential risks of deficiency and/or toxicity. Sensitivity to tannins has been investigated in different species, with a two-bottle preference test. We observed large variations that are likely to be adaptive to the concentrations in plant species in various environments. For instance, the rejection threshold for a mixture of tannin and fructose is much higher in Propithecus verreauxi (above 170 g/l) than in Microcebus murinus (0.54 g/l). Recognition thresholds can also vary slightly between human populations, in relation to ancient or recent food practices. There is also a wide range of taste sensitivity towards quinine, without any correlation, in this case, with body mass or other factors related to energy expenditure. Different habitats of Madagascar are compared according to the results of screening tests on tannins and alkaloids. The eastern rain forest (at Andasibe) present slightly lower proportion of plants with alkaloid-like reaction, and a significantly higher proportion of tannin-rich plants than both the gallery forest and the Didiereaceae bush in the south (at Berenty). The results have been related to the gustatory ability of lemur species having to cope with these secondary compounds, and the food niche of the different species.

Changes in the availability and uses of wild yams according to climatic dryness and land-cover in Western Burkina Faso (West Africa): a joint ecological and ethno-botanical approach using GIS and remote-sensing

The regional variability in the uses of wild yams is assessed according to their availability in relation with land-use and climatic conditions from the South to the North sudanian sectors in Western Burkina Faso. The study involves field studies and modelling of the geographical distribution of yams and seeks correlations between environmental and ethno-biological data. Terrain analysis consists of phyto-ecological surveys and interviews with local inhabitants. A cluster analysis of a multi-date image of data obtained by remote-sensing is used to assess land-cover. The Bayesian post-probabilities of occurrence of each species are inferred using Weight of Evidence modelling linked to a Geographical Information System. The model is implemented with land-cover units and annual Moisture Availability Index evidential-layers and is driven by species presence data. The probabilities of occurrence of each species throughout the whole area as well as within and without the protected areas and in the vicinity of the sites of enquiries are calculated. A multi-factorial analysis makes it possible to shed light on the relationships among land use, the availability of yams, the uses of yams, knowledge and local practice. Results provide statistical evidence of spatial association between the yam species and the environmental descriptors taken into account. The study also provides evidence of an important regional variability in the actual uses and knowledge of wild yams. The rather widespread use of wild yams as a food complement, in social relations and as merchandise in local trade in the North of the area studied, which is far less observed in the South, is one of the major components of this variability.

Leaf chemistry as a predictor of primate biomass and the mediating role of food selection: A case study in a folivorous lemur (Propithecus verreauxi)

Folivorous primate biomass has been shown to positively correlate with the average protein‐to‐fiber ratio in mature leaves of tropical forests. However, studies have failed to explain the mismatch between dietary selection and the role of the protein‐to‐fiber ratio on primate biomass; why do not folivores always favor mature leaves or leaves with the highest protein‐to‐fiber ratio? We examined the effect of leaf chemical characteristics and plant abundance (using transect censuses; 0.37 ha, 233 trees) on food choices and nutrient/toxin consumption in a folivorous lemur (Propithecus verreauxi) in a gallery forest in southern Madagascar. To assess the nutritional quality of the habitat, we calculated an abundance‐weighted chemical index for each chemical variable. Food intake was quantified using a continuous count of mouthfuls during individual full‐day follows across three seasons. We found a significant positive correlation between food ranking in the diet and plant abundance. The protein‐to‐fiber ratio and most other chemical variables tested had no statistical effect on dietary selection. Numerous chemical characteristics of the sifakas diet were essentially by‐products of generalist feeding and “low energy input/low energy crop” strategy. The examination of feeding behavior and plant chemistry in Old World colobines and folivorous prosimians in Madagascar suggests that relative lack of feeding selectivity and high primate biomass occur when the average protein‐to‐fiber ratio of mature leaves in the habitat exceeds a threshold at 0.4. Am. J. Primatol. 76:563–575, 2014.

Dioscorea orangeana (Dioscoreaceae), a new and threatened species of edible yam from northern Madagascar

SummaryA new species of yam (Dioscorea orangeana Wilkin) is described and illustrated. It differs from D. comorensis R.Knuth by having undulate leaf margins and a broader torus and tepals in both the male and female flowers. In female flowers of D. orangeana the floral stipe between the ovary and the torus is shorter than in D. comorensis. The tuber morphology of the species is atypical among Malagasy species in that there are several digitate lobes rather than a single tuber per growing season, although more research is needed on tuber morphology. D. orangeana is reported to be edible. It is endemic to the Forêt d’Orangea near Diego Suarez (Antsiranana) in Antsiranana Préfecture. Its conservation and sustainable use are thus matters of concern.

An endangered new species of edible yam (Dioscorea, Dioscoreaceae) from Western Madagascar and its conservation

SummaryA new species of Dioscorea from Morondava prefecture in Western Madagascar is described. Dioscorea bako Wilkin differs from D. alatipes Burkill & H. Perr. by its usually shallowly and irregularly lobed leaf margins, broader leaf blade (grey-green below), longer petiole and the broadly cuneate area where the petiole is inserted onto the leaf blade in the basal sinus. It is pubescent, especially densely on young shoots and inflorescences. It is endemic to Morondava Préfecture and is endangered under IUCN Red List category criteria (IUCN 2001). The unusual morphological features of its inflorescences, some of which are shared with D. alatipes are discussed. Dioscorea bako is a favoured food source for people of the Menabe region and is reported by them to be increasingly hard to find. Immediate conservation measures are necessary to ensure that it remains extant and, in the medium to long term, research should be undertaken to guide its sustainable utilisation.

The species of Dioscorea L. (Dioscoreaceae) from Madagascar with campanulate tori, including a new species from Eastern Madagascar

SummaryA revision of the Malagasy endemic species complex of yams (Dioscorea L.) which possesses flowers with campanulate tori is presented with keys and full descriptions. It comprises six species that were placed in Dioscorea sect. Seriflorae Burkill & H. Perrier and D. sect. Campanuliflorae Burkill & H. Perrier in the Flore de Madagascar et des Comores treatment. D. decaryana H. Perrier does not belong in the species complex. One species (D. kimiae Wilkin) is described and illustrated for the first time. It is found in light gaps in humid evergreen forest near Ambanizana on the Masoala peninsula and near Ranomafana in Fianarantsoa Prefecture. Recent collections demonstrate that D. madecassa H. Perrier and D. karatana Wilkin are conspecific, as are D. seriflora Jum. & H. Perrier and D. tanalarum H. Perrier. Three accepted species names (D. maciba Jum. & H. Perrier, D. seriflora Jum. & H. Perrier and D. tsaratananensis H. Perrier and two placed in synonymy (D. bararum H. Perrier and D. ovifotsy H. Perrier) are lectotypified. The species complex comprises one common, widespread species from deciduous Western vegetation, one widespread in humid eastern forests, and four with restricted distributions in evergreen forests of the Central Highlands and East of Madagascar. Their diversity and systematics are discussed.

The threatened edible yams of the Dioscorea sambiranensis R.Knuth species complex (Dioscoreaceae): a new species and subspecies.

Wilkin P., Hladik A., Jeannoda V. & Weber O. 2009. — The threatened edible yams of the Dioscorea sambiranensis R.Knuth species complex (Dioscoreaceae): a new species and subspecies. Adansonia, sér. 3, 31 (2): 249-266. ABSTRACT The Dioscorea sambiranensis species complex is endemic to Northern and North-Western Madagascar. Its taxa have broad, cordate leaves with petioles roughly equal in length to the blade, lax male inflorescences with flowers on long pedicels arranged in cymules of usually five or more flowers and flat discoid floral tori. Following study of its morphological variation, two new taxa in the complex are described and illustrated. Dioscorea buckleyana Wilkin was part of a mixed taxonomic concept under the invalid name D. sambiranensis R.Knuth subsp. ambrensis H.Perrier. It is glabrous like D. pteropoda H.Perrier, but differs in petiole and leaf blade morphology (especially blade texture), pedicel length and capsule morphology. Clarification of the limits of D. sambiranensis R.Knuth revealed an undescribed subspecies, subsp. bardotiae Wilkin, which differs in leaf blade and petiole dimensions, and lacks the surface ornamentation of the ovary and capsule found in subsp. sambiranensis. The relationship of D. sambiranensis with D. namorokensis Wilkin is revealed. Keys, descriptions and a distribution map are provided for all the taxa covered, and conservation status assessments given. The latter show that all of the taxa of the complex are, or are likely to be, threatened.

Biodiversité et développement : les paysans de Guinée

Une reflexion sur la biodiversite doit s’appuyer sur une representation dynamique des ecosystemes, des systemes techniques et des strategies d’utilisation des ressources, etant entendu qu’il n’y a pas de frontieres entre les milieux «naturels» et les espaces de mise en valeur. En Guinee maritime, les roles concomitants des principaux facteurs mesologiques et des modes de gestion favorisent une flore riche et diversifiee. Ces formations ont toutes ete largement manipulees depuis des siecles par les hommes. Cette mosaique est la garantie de la conservation des especes et joue un role fondamental pour la resilience des ecosystemes. Les ecosystemes actuels sont en equilibre dynamique avec les modes de gestion. Le souci de durabilite est au coeur des strategies des paysans. Aussi, il semble aujourd’hui pertinent de considerer les populations locales comme les premieres depositaires des moyens de conservation.