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The Kalambatritra Massif in south-east Madagascar supports a fairly extensive expanse of forest ranging in altitude from around 1,000 to 1,750 m. We conducted a collaborative lemur inventory in the Kalambatritra Special Reserve, located in the central part of the massif, in December 2015. We observed six lemur species including Eulemur collaris, Hapalemur meridionalis, Lepilemur wrightae, Microcebus sp., Cheirogaleus sp. and Avahi sp. We found feeding signs of aye-aye (Daubentonia madagascariensis) on bamboo culms. Local people claimed that ring-tailed lemurs (Lemur catta) still occur in the gallery forests to the west of the massif. Local people also claimed that in the east of the Reserve they had seen feeding signs on giant bamboos that might be an indication of the presence of greater bamboo lemurs (Prolemur simus). The dominant large-culmed bamboo present was Arundinaria sp., a genus known to occur at high elevations in Madagascar, and for which this record represents a southern extension to the known range of this genus in Madagascar. During nocturnal transects Kalambatritra sportive lemurs (Lepilemur wrightae) were the most frequently observed lemur. Our results confirm that the Kalambatritra Special Reserve still holds high densities of this species which currently is only known from the Kalambatritra massif. Further research is required in the Reserve to understand the factors affecting density of sportive lemurs here. [ABSTRACT FROM AUTHOR]

Tampolo forest, in the north east of Madagascar, is a protected area of littoral forest, managed by ESSA- Forêts of the University of Antananarivo. Five species of nocturnal lemur are thought to be present in the forest; the aye-aye (Daubentonia madagascariensis), brown mouse lemur (Microcebus rufus), greater dwarf lemur (Cheirogaleus major), weasel sportive lemur (Lepilemur mustelinus) and eastern woolly lemur (Avahi laniger). However, currently there is a paucity of data on the density and distribution of these species. We used 20 line transects (0.5km in length) and distance sampling techniques to establish population sizes of lemur species and analysed our results using the software DISTANCE 6.0. The characteristics of lemur-used trees were catalogued during day surveys and compared to those of randomly selected trees to determine which characteristics were ecologically important to lemur species. Results indicate that the estimated population size of A. laniger is 150 individuals/km² (95% confidence interval: 84-267) and of M. rufus is 323 individuals/km² (95% confidence interval: 199-523). Only 3 individuals of C. major were observed and no individuals of D. madagascariensis or L. mustelinus were detected during line transects. This suggests low population sizes or potential difficulty in detecting these species, especially D. madagascariensis, which is at low natural densities throughout Madagascar and, given human persecution, has a high tendency for flight in the presence of humans. The average diameter at breast height (DBH) and height of trees used by A. laniger and the average height of trees used by M. rufus were significantly different to randomly selected trees. This suggests that particular trees may be of higher ecological importance to these lemur species than others, which enhances problems caused by deforestation. Our results suggest that the phenology of the trees used by both of these species was not a significant factor, though exploration into previous research suggest that our data may have been biased by seasonality. Further research on feeding ecology would be necessary to determine whether this is an important factor concerning lemur abundance in Tampolo Forest. Repetitions of our study over years to come will also serve to monitor long-term population trends in the region. [ABSTRACT FROM AUTHOR]

Female dominance is a well-known trait of lemurs, although it has not been reported from all species and is still often unexplored, especially in the nocturnal species. We examined the intersexual dominance relationships in Microcebus ravelobensis, a congener of M. murinus who is well known for its female dominance. Given the many similarities in biology, it was predicted that M. ravelobensis should also possess female dominance. Seventeen unfamiliar male-female pairs were formed with animals captured in northwestern Madagascar and kept in a two-cage setting (one cage for each animal) for up to 1 week. Four encounter experiments were conducted with each pair. In contrast to the expectations, females were not consistently dominant over their male partners. Only 3 of 17 dyads developed a clear agonistic asymmetry, among which were two cases of male dominance and only one case of female dominance. Because body mass differences did not explain the findings, various other possible explanations are discussed. It is suggested that food may not be the driving factor of female dominance in mouse lemurs. Instead, it is hypothesized that species-specific differences in the quality of sleeping sites (i.e., tree holes) and in social grouping patterns may better explain why some mouse lemur species have female dominance, whereas others like the golden-brown mouse lemur do not. It is concluded thatthese arguments and hypotheses may even hold true for other solitary foragers and may thereby lead to a better understanding of the variable social evolution in lemurs and primates in general. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Seasonal changes may have a strong effect on the safety of sleeping sites in arboreal primates. For example, changes in vegetation thickness may impact predation risk and energy expenditure related to thermoregulation. We investigated how seasonality influenced sleeping site characteristics and usage pattern in an arboreal primate living in a highly seasonal environment. The western woolly lemur ( Avahi occidentalis) lives in the dry deciduous forest of northwestern Madagascar, where leaf coverage greatly varies across the year. We examined the hypothesis that these lemurs change their sleeping site behavior dependent on season. We collected data on sleeping site height and location, and characterized usage patterns in six radiotagged pairs between May and December 2008. During the late dry season, pairs preferentially slept in the middle part of a tree. In contrast, there was no height preference during the early rainy season. The lemurs used more sleeping sites during the early rainy than during the late dry season and stayed more days at the same sleeping tree in the late dry season. Our findings support the hypothesis that season affects sleeping site selection in an arboreal primate species living in a highly seasonal environment. During the late dry season, western woolly lemurs are particularly conspicuous to hunters and we therefore suggest a better monitoring of the forest in this season to guarantee their future survival. [ABSTRACT FROM AUTHOR]

The article presents a study that deals with the diet of nocturnal and diurnal chameleon predators on Madagascar. The authors reviewed available literature and identified 28 species. A summary was presented regarding predation of Malagasy chameleons and identify the main predators recorded. Studies that used stomach contents or pellet analysis were the sources of the research. The authors also offered information on observations and descriptions of predators feeding on chameleons. Identified as the principal avian predators of Furcifer spp. and Calumma spp. and the Brachypteracias leptosomus of Brokesia spp. were Eutriorchis astur and Falco zonventris.

Greater dwarf lemurs ( Cheirogaleus major) are small nocturnal primates from the rain forests of eastern Madagascar. I investigated a population of Cheirogaleus major in a littoral rain forest of Southeast Madagascar during 2 rainy seasons to supplement the sparse information available for the species. I collected data on morphology, group composition, sleeping behavior, home range, and social organization via mark/recapture, radio telemetry, and focal individual observations. I identified 2 presumed family groups, and my data from radiotracking revealed a monogamous social organization. In each group, I found an adult pair and its presumed offspring sharing home ranges and sleeping sites together. I also observed gregarious behavior of group members during their nocturnal activity. I found no difference in body measurements between sexes, but body mass and tail circumference increased significantly from November to February, indicating a fatting period before hibernating. [ABSTRACT FROM AUTHOR]

1. Predatory mammals and birds from several phylogenetic lineages use prey rustling sounds to detect and locate prey. However, it is not known whether these rustling sounds convey information about the prey, such as its size or profitability, and whether predators use them to classify prey accordingly. 2. We recorded rustling sounds of insects in Madagascar walking on natural substrate and show a clear correlation between insect mass and several acoustic parameters. 3. In subsequent behavioural experiments in the field, we determined whether nocturnal animals, when foraging for insects, evaluate these parameters to classify their prey. We used field-experienced Grey Mouse Lemurs Microcebus murinus in short-term captivity. Mouse Lemurs are generally regarded as a good model for the most ancestral primate condition. They use multimodal sensorial information to find food (mainly fruit, gum, insect secretions and arthropods) in nightly forest. Acoustic cues play a role in detection of insect prey. 4. When presented with two simultaneous playbacks of rustling sounds, lemurs spontaneously chose the one higher above their hearing threshold, i.e. they used the rustling sound's amplitude for classification. We were not able, despite attempts in a reinforced paradigm, to persuade lemurs to use cues other than amplitude, e.g. frequency cues, for prey discrimination. 5. Our data suggests that Mouse Lemurs, when foraging for insects, use the mass–amplitude correlation of prey-generated rustling sounds to evaluate the average mass of insects and to guide their foraging decisions. [ABSTRACT FROM AUTHOR]

Several ecological and physiological factors have been suggested to structure circadian activity in cathemeral primates, i.e., those that are regularly active both day and night, but their relative importance remains controversial. We studied the nocturnal activity of a group of cathemeral redfronted lemurs (Eulemur fulvus rufus ) in Kirindy Forest in Western Madagascar to examine its relationship with one environmental factor, ambient light levels, in detail. To this end, nightly travel distances and moon luminosity were determined between March and June 1996. During this transitional period between the wet and dry seasons these red-fronted lemurs were regularly active at night, and traveled significantly larger distances during full-moon nights compared to new-moon nights. The importance of ambient luminosity for nocturnal activity was highlighted by observations during a total lunar eclipse (i.e., during a full-moon night), which caused abrupt cessation of the animal’s activity. Our results support the hypothesis that nocturnal activity of these cathemeral lemurs is regulated also by changes in ambient light levels. Am. J. Primatol. 53:69–78, 2001. © 2001 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]