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Toliara, Madagascar

Bolt L.M.,University of Toronto | Sauther M.L.,University of Colorado at Boulder | Cuozzo F.P.,University of North Dakota | Youssouf Jacky I.A.,University of Toliary
Folia Primatologica | Year: 2015

The ring-tailed lemur (Lemur catta) is a group-living strepsirrhine primate endemic to Madagascar that faces considerable predation pressure from aerial and terrestrial predators. This species engages in mobbing and vigilance behavior in response to predators, and has referential alarm vocalizations. Because L. catta is female dominant, less is known about the alarm calls of males. We tested 3 hypotheses for male antipredator vocalization behavior on L. catta at the Bezà Mahafaly Special Reserve in Madagascar: the predator confusion, group maintenance, and predation risk allocation hypotheses. We found support for 2 hypotheses. When a male L. catta made an antipredator call, other group members vocalized in response. Dominant males did not make alarm calls at higher rates than subordinate males. Predators were more abundant on the western side of Parcel 1, but an even greater number of antipredator vocalizations occurred in this area than predator abundance warranted. We show that male L. catta consistently participated in group-level antipredator vocalization usage in high-risk locations. Although female L. catta are known to hold the primary role in group defense, male L. catta are also key participants in group-wide behaviors that may confuse or drive away predators. © 2015 S. Karger AG, Basel. Source

Morteani G.,TU Munich | Kostitsyn Y.A.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Gilg H.A.,TU Munich | Preinfalk C.,Ludwig Maximilians University of Munich | Razakamanana T.,University of Toliary
International Journal of Earth Sciences | Year: 2013

The phlogopite, diopside, calcite, anhydrite and apatite pegmatites of Ampandrandava and Beraketa are examples for the many other pegmatites of similar silicocarbonatitic composition found in the Bekily and Betroka-Beraketa Precambrian belts of southern Madagascar. The two studied pegmatites and associated syenites crystallised from immiscible silicocarbonatitic and peralkaline syenitic melts in a time span between 515 and 504 Ma in the final extensional phase of the Panafrican continental collision and connected metamorphic/metasomatic event. Model TNd ages suggest that the melts were produced by partial melting of 3. 5 Ga partially evaporitic continental crust. The studied pegmatites and genetically associated syenitic rocks are very rare examples for crustal silicocarbonatitic melts generated in a Panafrican collisional setting. The overwhelming majority of carbonatites and associated peralkaline rocks are mantle derived, much poorer in phosphate and sulfate and found in a cratonic environment. In light of the present results, genetic models for other sulfate- and phosphate-rich magmatic rocks (e. g., phlogopite-apatite-calcite mineralisations in the Grenville-Hasting formation in Canada and in the Sludyanka group in Eastern Siberia) should be reevaluated. © 2012 Springer-Verlag Berlin Heidelberg. Source

LaFleur M.,University of Colorado at Boulder | Sauther M.,University of Colorado at Boulder | Cuozzo F.,University of Colorado at Boulder | Cuozzo F.,University of North Dakota | And 3 more authors.
Primates | Year: 2014

Cathemerality consists of discrete periods of activity during both the day and night. Though uncommon within Primates, cathemerality is prevalent in some lemur genera, such as Eulemur, Hapalemur, and Prolemur. Several researchers have also reported nighttime activity in Lemur catta, yet these lemurs are generally considered "strictly diurnal". We used behavioral observations and camera traps to examine cathemerality of L. catta at the Tsimanampetsotsa National Park, Madagascar. Nighttime activity occurred throughout the study period (September 2010-April 2011), and correlated with warm overnight temperatures but not daytime temperatures. Animals spent 25 % of their daytime active behaviors on the ground, but appeared to avoid the ground at night, with only 5 % of their time on the ground. Furthermore, at night, animals spent the majority of their active time feeding (53 % nighttime, 43 % daytime). These findings imply that both thermoregulation and diet play a role in the adaptive significance of cathemerality. Additionally, predator avoidance may have influenced cathemerality here, in that L. catta may limit nighttime activity as a result of predation threat by forest cats (Felis sp.) or fossa (Cryptoprocta ferox). Further data are needed on cathemeral lemurs generally, but particularly in L. catta if we are to fully understand the evolutionary mechanisms of cathemerality in the Lemuridae. © 2013 Japan Monkey Centre and Springer Japan. Source

Hubert N.,University of Reunion Island | Hubert N.,University of Perpignan | Meyer C.P.,Smithsonian Institution | Bruggemann H.J.,University of Reunion Island | And 6 more authors.
PLoS ONE | Year: 2012

Diversity in coral reef fishes is not evenly distributed and tends to accumulate in the Indo-Malay-Philippines Archipelago (IMPA). The comprehension of the mechanisms that initiated this pattern is in its infancy despite its importance for the conservation of coral reefs. Considering the IMPA either as an area of overlap or a cradle of marine biodiversity, the hypotheses proposed to account for this pattern rely on extant knowledge about taxonomy and species range distribution. The recent large-scale use of standard molecular data (DNA barcoding), however, has revealed the importance of taking into account cryptic diversity when assessing tropical biodiversity. We DNA barcoded 2276 specimens belonging to 668 coral reef fish species through a collaborative effort conducted concomitantly in both Indian and Pacific oceans to appraise the importance of cryptic diversity in species with an Indo-Pacific distribution range. Of the 141 species sampled on each side of the IMPA, 62 presented no spatial structure whereas 67 exhibited divergent lineages on each side of the IMPA with K2P distances ranging between 1% and 12%, and 12 presented several lineages with K2P distances ranging between 3% and 22%. Thus, from this initial pool of 141 nominal species with Indo-Pacific distribution, 79 dissolved into 165 biological units among which 162 were found in a single ocean. This result is consistent with the view that the IMPA accumulates diversity as a consequence of its geological history, its location on the junction between the two main tropical oceans and the presence of a land bridge during glacial times in the IMPA that fostered allopatric divergence and secondary contacts between the Indian and Pacific oceans. © 2012 Hubert et al. Source

Tucker B.,University of Georgia | Tsimitamby M.,University of Toliary | Humber F.,Blue Ventures Conservation | Benbow S.,Blue Ventures Conservation | Iida T.,Research Center for Cultural Resources
Human Organization | Year: 2010

International programs for combating food insecurity including the recent FAO "How to Feed the World in 2050: Highlevel Expert Forum" promote agricultural intensification among the main solutions to global hunger. We argue here that hunting and gathering on land and at sea will often result in less food insecurity than farming. In southwestern Madagascar, questionnaire data find farmers more food insecure than neighboring forest foragers and marine foragers. Production data show that farmers produce a greater quantity of food energy, but foragers sell their goods for higher prices resulting in comparable market-valued incomes among all three subsistence modes. A stochastic model finds farming portfolios an order of magnitude more risky (lower z-scores) than foraging portfolios, except when foraging portfolios have low means. This is because farmers experience only three to five harvests per year while foragers may experience 365 harvests. As farmers await future harvests of uncertain quantity, they are more likely than foragers to depend on formal and informal credit. The stochastic model shows that diversification, mixing foraging with farming, can only reduce the risks of farming under limited conditions. We conclude that pressuring foragers to become farmers will increase rather than diminish regional food insecurity. Source

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