Dominance status in female ring-tailed lemurs (Lemur catta) has a pervasive effect upon social organization, however the proximate mechanisms underlying female rank-relations remain poorly understood. I investigated how four such attributes - weight, age, agonistic frequency, and fecal testosterone levels - relate to female rank-order wild ring-tailed lemurs at the Beza Mahafaly Special Reserve, Madagascar. My results indicated that: (1) The mean weight of high-ranking females is significantly greater than in lower-ranking females; (2) The relationship of age in relation to rank follows an inverted J-shaped pattern, with old adults attaining the highest average rank, followed by prime adults, young adults, and very old adults; (3) Significant, positive correlations between rank and rates of agonism exist in four of the six study groups; and (4) The effect of rank on mean testosterone concentration was significant in one social troop, in which the two highest ianking females exhibited significantly lower mean testosterone levels.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Not available

Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendix: leaves 40-42. Includes bibliographical references (leaves 43-47 ).

Global climate change and habitat fragmentation represent two of the greatest threats to biodiversity and ecological processes worldwide. It is predicted that anthropogenic induced climate change could represent a key factor for extinctions in the near future, considering that the Earth is set to become warmer than at any period in the past 40 million years. Habitat fragmentation and isolation pose a number of challenges for the fauna inhabiting degraded areas, including lack of dispersal opportunities leading to inbreeding resulting in a loss of genetic diversity, reduced reproductive fitness; increases in vulnerability to predation, hunting, and disease, and an inability to deal with or respond to environmental changes and/or disease. Madagascar, the fourth largest island in the world, is home to unprecedented levels of endemism, including over 100 species of lemur. The island has undergone a range of historical and contemporary landscape transformations, both natural and anthropogenic. These landscape transformations combined with additional human-induced disturbances, such as the illegal pet and bushmeat trades, have had devastating effects on the island’s extant primate populations. Thus, Madagascar’s lemurs have been deemed the most endangered group of mammals and now represent the highest primate conservation priority in the world. The ring-tailed lemur (Lemur catta) is endemic to the southern regions of the island and occupies an array of habitats. L. catta is known for its remarkable behavioral and ecological flexibility, which contributes to its ability to exist in a mostly fragmented landscape. While this species represents one of the most well studied Malagasy strepsirhines, there has been a paucity of research regarding the population and conservation genetics of this endangered species. The goal of my dissertation was to examine the influence of habitat fragmentation and isolation on the genetic diversity and population structuring of this flagship species in three populations living in the central highlands of Madagascar: Anja Reserve, Sakaviro, and Tsaranoro Valley. Non-invasive fecal samples from 30 individual lemurs were collected from three fragmented forests and genotyped at six polymorphic microsatellite loci. Population genetic analyses were examined via GenAlEx software and revealed a moderate level genetic diversity. Genetic differentiation (FST) among the three fragmented populations ranged from 0.05-0.11. These data suggest that the L. catta populations within south-central Madagascar have not yet lost significant genetic variation. To examine past and recent demographic declines or genetic bottlenecks, I employed three approaches, including mode-shift and M-Ratio tests, as well as a test to detect heterozygosity excess using three mutation models: the two-phase model (TPM), step-wise mutation model (SMM), and the infinite allele model (IAM). Results were equivocal depending on the test that was applied; however, a mode-shift was detected for Anja, signifying this population underwent a historical bottleneck. M-ratio tests revealed that all three populations suffered historical bottlenecks. A population bottleneck was indicated via heterozygosity excess under the IAM for both the Anja and Sakaviro populations. To understand the impact of natural (e.g., mountains) and anthropogenic disturbances (e.g., roads, habitat fragmentation) on male reproductive strategies (dispersal) and population structuring, I utilized both GenAlEx and STRUCTURE software. Population assignment analyses suffered from a likely ‘lack of signal’. Therefore, individuals were unable to be reliably assigned to their population of origin. Genetic population structure was ambiguous. These data suggest that that these three fragmented populations are not genetically differentiated enough for proper population assignment, or perhaps the sample is not robust enough for population assignment analyses to produce unequivocal results. My research represents the first population genetic data for ring-tailed lemurs within the central highlands, and thus, serves as a baseline for future investigations into the genetic health of these populations. These data support the suggestion that these three fragments represent areas in which concerted conservation efforts are necessary if genetic diversity is to be maintained and future demographic declines are to be prevented. My results are informative for the local community conservation associations working within south-central Madagascar and can now be applied to determine areas of conservation priority and where forest corridors will be the most beneficial for maintaining gene flow. The loss and fragmentation of habitat continues across Madagascar, including the central highlands; thus, all remaining L. catta populations should be considered a high conservation priority. If we are to safeguard the long-term viability of this species, continued conservation and research initiatives will be crucial. / Graduate / 0327 / 0369 / lemurgirl.clarke@gmail.com

Title from title page of PDF (University of Missouri--St. Louis, viewed March 8, 2010). Includes bibliographical references.

In an effort to better understand primate behavioural flexibility and responses to low-biomass habitats, behavioural patterns of ring-tailed lemurs (Lemur catta) living in a xerophytic spiny forest habitat in southern Madagascar were examined. Behavioural data were collected over two months on two separate groups living in two distinctly different habitats: a sub-desert spiny forest and a riverine gallery forest. Data on the following behavioural categories integral to primate sociality were collected: time allocation, anti-predator vigilance, predator sensitive foraging, feeding competition, and affiliative behaviour. L. catta living in the spiny forest habitat differed significantly in many behavioural patterns when compared to L. catta living in the gallery forest. I suggest that the ability to successfully alter behavioural strategies to varying ecological conditions allows ring-tailed lemurs to occupy low biomass habitats which are uninhabitable to nearly all other primate species in Madagascar. Lemur catta evolution, behavioural flexibility, and conservation will be discussed.

In an effort to better understand primate behavioural flexibility and responses to low-biomass habitats, behavioural patterns of ring-tailed lemurs (Lemur catta) living in a xerophytic spiny forest habitat in southern Madagascar were examined. Behavioural data were collected over two months on two separate groups living in two distinctly different habitats: a sub-desert spiny forest and a riverine gallery forest. Data on the following behavioural categories integral to primate sociality were collected: time allocation, anti-predator vigilance, predator sensitive foraging, feeding competition, and affiliative behaviour. L. catta living in the spiny forest habitat differed significantly in many behavioural patterns when compared to L. catta living in the gallery forest. I suggest that the ability to successfully alter behavioural strategies to varying ecological conditions allows ring-tailed lemurs to occupy low biomass habitats which are uninhabitable to nearly all other primate species in Madagascar. Lemur catta evolution, behavioural flexibility, and conservation will be discussed.

Ring-tailed lemur Lemur catta, red ruffed lemur Varecia rubra and black and white ruffed lemur Varecia variegata belongs to the family Lemuridae, living at Madagaskar as endemits. In wildlife is folivorous and frugivorous food strategy at the both genus ? in the process g. Varecia is more frugivorous. Study was divided into two parts ? the first about ration of feeding chosen species of lemurs in several czech zoos and the second about ethology feeding behaviour lemurs in zoo Jihlava. For nutritional assessment were further chosen zoos Lešná, Jihlava, Ústí nad Labem, Ohrada and Chleby. From ration of feeding for chosen species of lemurs was counted average personal ration per day. This average was used to calculate nutritional values of dietary (fats, protein, carbohydrates, fiber, calcium, phosporus and iron) for each kind of menu or particularly day a week. For ethologic observation was made method of straight observation with used behaviour sampling ? scanning of a behaviour. Observation was done from July to December 2011 in whole extent 56 hours. Study solved out that ration of feeding are very different in each zoo like nutritional values of dietary and amount. In each zoo has larger ration of feeding Varecia rubra than Lemur catta. In average this diference beetwen that makes 144,25 g. Observation (zoo Jihlava) showed that Lemur catta spends foraging behaviour 19,75 minutes per day and handling 42,75 minutes per day in average. All in all they spending their feeding behavior only 62,5 minutes (1,04 hours) per day. Further more was discovered diference in length feeding behaviour when in their habitation more tree branches were. Adding branches to there increased length of feeding behaviour about of 22,67 minutes per day.