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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Variation in predator communities and anti-predator behaviors of Milne-Edwards' sifakas (Propithecus edwardsi) in southeastern Madagascar

Kotschwar, Mary Wynne 10 August 2010 (has links)
To advance conservation in the increasingly fragmented landscape of Madagascar, we must examine the persistence and interactions of species in human-disturbed habitats. I investigated lemur-predator interactions in southeastern Madagascar through a comparison of predator communities and anti-predator behaviors of Milne-Edwards' sifakas (Propithecus edwardsi) in the continuous rainforest of Ranomafana National Park, and the forest fragments of Ialatsara Forest Station. I confirmed the presence of potential aerial predators at each site, but the sifakas' confirmed native mammalian predator, fossa (Cryptoprocta ferox), was absent from the fragmented site. Playbacks of predator vocalizations did not suggest that fragment-living sifakas have weakened anti-predator responses, but that their responses may be less specific than those of conspecifics in the continuous forest. I found that fragment-living sifakas displayed less downward vigilance and more frequently used low canopy heights; these behaviors may increase their vulnerability to recolonizing ground predators. I investigated local ecological knowledge (LEK) of carnivore ecology in communities 0–20 km from continuous forest to explore the potential for such recolonization. My findings from 182 interviews in 17 communities suggest that the fossa is especially sensitive to anthropogenic disturbance; it was only observed in communities ≤ 2.5 km from the continuous forest within the last five years. In contrast, the introduced small Indian civet (Viverricula indica) and wild cat (Felis silvestris) were distributed ubiquitously and displayed an affinity to human-dominated habitats. LEK surveys can provide information on the poorly understood responses of the Malagasy carnivores to the threats they face in a changing landscape. / Master of Science
32

The Biodiversity Mirage: the Effects of Habitat Degradation and Exotic Predators on Ground-Dwelling Forest Birds, Tenrecs and Lemurs in Northeastern Madagascar

Murphy, Asia J. 03 June 2015 (has links)
Madagascar is one of the world's top conservation priorities due to the intense anthropogenic pressures on its diverse and endemic wildlife. There have been very few studies conducted in the largest protected area complex in Madagascar, the Masoala-Makira landscape (northeastern Madagascar). My goal was to examine the response of ground-dwelling forest birds, tenrecs (Lipotyphla: Tenrecidae) and lemurs to habitat degradation and the presence of exotic predators, and monitor population trends at resurveyed sites from 2008 to 2013. Using camera trap surveys and distance sampling, we observed 26 bird species (n = 4,083 observations), three spiny tenrec species (n = 244 observations) and 12 lemur species (n = 1,172 observations). Out of 13 focal species (seven bird, three tenrec and three lemur species), seven had higher point estimates of occupancy or density at intact forests when compared to intermediately degraded or degraded forest sites. Common tenrecs (Tenrec ecaudatus) and cathemeral lemurs changed their activity patterns, becoming more nocturnal in degraded forests. Feral cat (Felis sp.) trap success was negatively related to the detection of three bird species (red-breasted coua, Coua serriana; scaly ground-roller, Geobiastes squamiger; and Madagascar crested ibis, Lophotibis cristata). At two resurveyed sites (S02 and S05), out of 19 and 17 species, only four and eight species did not show consistent declines in occupancy or encounter rates, respectively, over a six-year period. This research highlights the urgent need for immediate conservation action in the Masoala-Makira protected area complex in order to protect one of the world's biodiversity hotspots. / Master of Science
33

Species delimitation, phylogeography and population genetics of the endemic Malagasy dwarf lemurs (genus Cheirogaleus) / Artabgrenzung, Phylogeographie und Populationsgenetik der enedemischen, madagassischen Katzenmakis (Gattung Cheirogaleus)

Groeneveld, Linn Fenna 18 April 2008 (has links)
No description available.
34

Prévalence d’excrétion de Giardia et Cryptosporidium chez les humains, les animaux domestiques et les lémuriens de l’écosystème du Parc National de Ranomafana, Madagascar

Rasambainarivo, Fidisoa Thierry 03 1900 (has links)
L’augmentation des interactions entre humains et animaux sauvages en lisière des habitats naturels pourrait faciliter la transmission d’agents pathogènes entre les humains et les différentes espèces animales d’un écosystème et ainsi favoriser l’émergence de maladies. Nous avons effectué une étude transversale portant sur l’infection par Giardia et Cryptosporidium chez les humains, les animaux domestiques, les rongeurs et les lémuriens au sein de l’écosystème de Ranomafana, Madagascar. Des échantillons de fèces ont étés collectés de manière non invasive chez des personnes volontaires, des mammifères domestiques et des rongeurs introduits habitant trois villages situés en lisière du Parc National de Ranomafana (PNR) ainsi que quatre espèces de lémuriens (Propithecus edwardsii, Prolemur simus, Eulemur rubriventer et Microcebus rufus) du PNR. Des analyses coproscopiques par la technique d’immunofluorescence directe ont été réalisées afin de détecter la présence de Cryptosporidium et Giardia. Leur prévalence a été estimée et certaines variables reliées à l’infection par les parasites ont été identifiées. Cryptosporidium et Giardia ont été détectés avec une prévalence estimée à 22,9 % et 13,6 % respectivement chez les humains. La prévalence de ces deux parasites variait de 0 % à 60 % chez les animaux domestiques et les rongeurs au sein des villages. L’espèce hôte, l’âge ainsi que la co-infection par un autre protozoaire sont les seules variables associées à l’infection par Cryptosporidium et Giardia dans cet écosystème tandis qu’aucune association avec une coinfection par un ordre de nématode n’a été détecté. De plus, Cryptosporidium a été détecté chez 10,5 % des lémuriens du PNR. Cette étude documente pour la première fois la présence de Cryptosporidium chez deux espèces de lémuriens du PNR. Par contre, Giardia n’a pas été détecté dans les échantillons issus de lémuriens du PNR. / Increasing human activities in the vicinities of natural habitats may facilitate the emergence and transmission of diseases between humans and domestic animals and wildlife species. We conducted a cross-sectional study investigating the prevalence of Giardia and Cryptosporidium, two ubiquitous and potentially zoonotic protozoan parasites in various populations of humans and animals from the Ranomafana National Park ecosystem (RNP), Madagascar. Fecal samples were obtained non-invasively from human volunteers, domestic animals and introduced rodents inhabiting three villages in the vicinity of the national park and from four species of free-ranging lemurs (Propithecus edwardsi, Prolemur simus, Eulemur rubriventer and Microcebus rufus) from the RNP. Samples were analyzed using the direct immunofluorescence technique. Prevalences of Giardia and Cryptosporidium were estimated and variables associated with infections by the protozoa were identified. Cryptosporidium and Giardia were detected with a prevalence of 22.9 % and 13.6 % in humans respectively. The prevalences of these two parasites varied from 0 % to 60 % in domestic animals and introduced rodents from the villages. Species, age category and co-infection with the other protozoan were significantly associated with the infection by Cryptosporidium and Giardia in this ecosystem, whereas coinfections by different helminths order were not significantly associated with Cryptosporidium or Giardia. Moreover, Cryptosporidium was detected in 10.5 % of lemurs sampled from the RNP. This study reports for the first time the occurrence of Cryptosporidium in two species of lemurs from the RNP. Giardia was not detected in fecal samples from lemurs inhabiting the RNP.
35

Adult female feeding competition within two groups of free-ranging ringtailed lemurs (Lemur catta) in different habitats at the Beza Mahafaly Special Reserve, Southwestern Madagascar

Gemmill, Andrea 30 August 2007 (has links)
Diet and female feeding competition was examined within two groups of free-ranging ringtailed lemurs (Lemur catta) at the Beza Mahafaly Special Reserve in southwestern Madagascar. The first group’s home range was located within a protected gallery forest, the second is in a degraded forest and human-occupied area. The diets of the females were found to vary between groups; females fed on different plant species, and those in the unprotected area frequently consumed human food scraps and domestic animal fecal matter. Contest and scramble competition were detected within both groups. Rates of feeding competition were found to increase according to the type of food being consumed; feeding on fruits and leaves correlated with increased competition in the reserve group, and feeding on human foods and animal fecal matter correlated with increased competition with the non-reserve group. These dietary and competitive differences highlight the need for continued, and possibly additional, protection of L. catta in this region.
36

Adult female feeding competition within two groups of free-ranging ringtailed lemurs (Lemur catta) in different habitats at the Beza Mahafaly Special Reserve, Southwestern Madagascar

Gemmill, Andrea 30 August 2007 (has links)
Diet and female feeding competition was examined within two groups of free-ranging ringtailed lemurs (Lemur catta) at the Beza Mahafaly Special Reserve in southwestern Madagascar. The first group’s home range was located within a protected gallery forest, the second is in a degraded forest and human-occupied area. The diets of the females were found to vary between groups; females fed on different plant species, and those in the unprotected area frequently consumed human food scraps and domestic animal fecal matter. Contest and scramble competition were detected within both groups. Rates of feeding competition were found to increase according to the type of food being consumed; feeding on fruits and leaves correlated with increased competition in the reserve group, and feeding on human foods and animal fecal matter correlated with increased competition with the non-reserve group. These dietary and competitive differences highlight the need for continued, and possibly additional, protection of L. catta in this region.
37

A Dental Topographic Analysis of Deciduous Tooth Wear in Hominoids

January 2016 (has links)
abstract: Early weaning, slow somatic and dental growth, and late age at reproduction are all part of a suite of energetic trade-offs that have shaped human evolution. A similar suite of energetic trade-offs has shaped the evolution of the indriid-palaeopropithecid clade, though members of this clade exhibit extremely fast dental development and nearly vestigial deciduous teeth. The development and functional occlusion of the primary postcanine dentition (i.e., deciduous premolars and molars) coincides with several life history parameters in great apes and indriids. This dissertation explored great ape dental macrowear, molar development in indriids, and molar size in lemurs with a broader goal of improving reconstructions of life history profiles in extinct primates. To this aim, macrowear and dental development were analyzed in apes and lemurs, respectively. Occlusal casts (six great ape species; N=278) were scanned to track mandibular fourth deciduous premolar (dp4) macrowear. Utilizing dental topographic analyses, changes in occlusal gradient and terrain were quantified. A subset of the great ape data (four species; n=199) was analyzed to test if differences in dp4 wear correlate with age at weaning. Using dental histology, molar development was reconstructed for Indri indri (n=1) and Avahi laniger (n=1). Life history and molar size data were collected from the literature. The results of this dissertation demonstrate that most great apes exhibited evidence of topographic maintenance, suggesting dp4s wear in a manner that maintain functional efficiency during growth and development; however, the manner in which maintenance is achieved (e.g., preservation of relief or complexity) is species specific. Dp4 macrowear is not correlated with age at weaning in great apes and is probably unreliable to reconstruct age at weaning in hominins. The pace of molar development in members of the indriid- palaeopropithecid clade did not correlate with body or brain size, an association present in several other primates. Associations of molar size with age at weaning suggest that expanding other developmental models (e.g., the inhibitory cascade) to life history is worth consideration. The broad variation in macrowear, dental development, and size highlights how the primary dentition may correlate with different life history parameters depending on the species and ecological setting, an important consideration when using teeth to reconstruct life history profiles. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2016
38

Primates, poison, and cytochrome P450: Evolutionary dynamism of the CYP1-3 gene families within the primate order

Chaney, Morgan Edward 24 April 2023 (has links)
No description available.
39

Variation in susceptibility to parasite infection: patterns, determinants and consequences in red-fronted lemurs / Variation in der Anfälligkeit für Parasiteninfektionen: Muster, Determinanten und Konsequenzen bei Rotstirnmakis

Clough, Dagmar 01 September 2009 (has links)
No description available.
40

Ecological determinants of social systems: Comparative and experimental feeding ecology of two mouse lemur species (<i>Microcebus berthae, M. murinus</i>) / Ökologische Determinanten von Sozialsystemen: vergleichende und experimentelle Nahrungsökologie von zwei Mausmaki-Arten (<i>Microcebus berthae, M. murinus</i>)

Dammhahn, Melanie 14 July 2008 (has links)
No description available.

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