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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.
1

Individual-based ecological model of urban resource patch use by Mexican free-tailed bats in Austin, Texas /

Taylor, Emariana, January 1900 (has links)
Thesis (Ph. D.)--Texas State University--San Marcos, 2009. / Vita. Appendices: leaves 126-130. Includes bibliographic references (leaves 131-143). Also available on microfilm.
2

Genetic diversity of the Chaerephon leucogaster/pumilus complex from mainland Africa and the western Indian Ocean islands.

Naidoo, Theshnie. 11 September 2014 (has links)
Chaerephon (Dobson, 1874), an Old World genus belonging to the family Molossidae, is part of the suborder Vespertilioniformes. Members of this genus are distributed across mainland Africa (sample sites; Tanzania, Yemen, Kenya, Botswana, South Africa and Swaziland), its offshore islands (Zanzibar, Pemba and Mozambique Island), Madagascar and the surrounding western Indian Ocean islands (Anjouan, Mayotte, Moheli, Grande Comore, Aldabra and La Reunion). A multifaceted approach was used to elucidate the phylogenetic and population genetic relationships at varying levels amongst these different taxa. Working at the subspecific level, I analysed the phylogenetics and phylogeography of Chaerephon leucogaster from Madagascar, based on mitochondrial cytochrome b and control region sequences. Cytochrome b genetic distances among C. leucogaster samples were low (maximum 0.35 %). Genetic distances between C. leucogaster and C. atsinanana ranged from 1.77 % to 2.62 %. Together, phylogenetic and distance analyses supported the classification of C. leucogaster as a separate species. D-loop data for C. leucogaster samples revealed significant but shallow phylogeographic structuring into three latitudinal groups (13º S, 15 - 17º S, 22 - 23º S) showing exclusive haplotypes which correlated with regions of suitable habitat defined by ecological niche modelling. Population genetic analysis of D-loop sequences indicated that populations from Madagascar have been expanding since 5 842 - 11 143 years BP. At the infra-generic level, I carried out analyses of sequences of the mitochondrial cytochrome b gene and control region, and the nuclear RAG2 region, to resolve the evolutionary history and taxonomy of the C. pumilus species complex from Africa and the western Indian Ocean islands. The nominate form comprised C. pumilus from Massawa, Eritrea, and this was genetically distinct from all other forms of Chaerephon. Our molecular evidence does not support that the syntype of C. limbatus and the holotypes of C. elphicki and C. langi and topotype of C. naivashae are specifically distinct from C. pumilus s.s. There is evidence of introgression of both C. pusillus and C. pumilus s.l. (south eastern Africa) mitochondrial haplotypes into C. leucogaster. The C. pumilus species complex has several attributes of a ring species, but appears to differ from this model in some important respects. It occurs on the African mainland and western Indian Ocean Islands, including Madagascar, ringing a potential barrier to gene flow, the Mozambique Channel. The taxa within the species complex form a ring in which the differentiated terminal forms, C. pusillus and C. leucogaster, occur in sympatry on Mayotte (Comoro Islands). Although there is evidence of isolation by distance around the ring, there is also a relatively high degree of genetic structure and limited gene flow. It appears that the island-based component species may have differentiated in allopatry, with some gene flow by over water dispersal, whereas the African mainland species may have differentiated through isolation by distance. A further study was aimed at re-examining the phylogeny of C. pumilus sensu lato from south eastern Africa based on a considerably larger sample set with a wider geographic range; I confirmed the previously-reported phylogenetic structure, and identified an additional strongly-supported control region clade. Discriminant Function Analysis based on four echolocation parameters could not discriminate between these clades. The hypothesised existence of cryptic species with distinct echolocation characteristics was not supported. Indices of diversity and neutrality, combined with a ragged multimodal mismatch distribution, are inconsistent with demographic expansion of a single C. pumilus south eastern African population and suggest that the control region lineages are stable populations at demographic equilibrium that were established during the late Pleistocene between 60 000 and 13 000 years ago. Further, more variable markers (microsatellites) were employed for finer-scale resolution of population genetic structure among the five genetic lineages of C. pumilus sensu lato found in the Durban area of KwaZulu-Natal, and to search for hybridization between these lineages. We recovered strong mitochondrial genetic structure, with 90% of the molecular variance occurring among four phylogenetically-defined groups, and a high significant Fst (0.897). Microsatellite data recovered three admixed populations with 3% of the nuclear variance occurring among populations, and global (Fst=0.037) and pairwise Fst values among populations were low and not significant. This is indicative of little genetic structure among the groups of C. pumilus s.l., which appear to comprise a single interbreeding population. Such high levels of mitochondrial genetic structure in the absence of significant nuclear structure are consistent with social isolation mechanisms such as female philopatry, and may reflect introgression of mitochondrial genes due to past hybridisation events with mitochondrially-distinct forms from outside the sampled area. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.
3

Patterns of genetic variation in Mops leucostigma (Molossidae) from Madagascar and the Comoros.

Hoosen, Nikhat. January 2008 (has links)
The synanthropic molossid bat, Mops leucostigma (Allen 1918), is widely distributed across Madagascar and has recently been described from the Comoros. M. leucostigma individuals from eastern Malagasy populations are markedly larger than those from the west, and Mops leucostigma populations from Madagascar are morphologically distinct from populations of its putative sister species, Mops condylurus from mainland Africa (Ratrimomanarivo et al. in press, Genetic diversity was assessed by sequencing the mitochondrial cytochrome b (n = 56) and displacement loop (D-loop) (n = 64) regions of Mops leucostigma individuals from a broad range of locations across Madagascar, and Mohéli and Anjouan in the Comoros. Specimens of Mops condylurus (n =3), Mops midas (n =3) and Otomops martiensseni (n = 1) were included in the study for comparative purposes as outgroups. Phenetic and cladistic analysis of cytochrome b and D-loop sequences strongly supported the reciprocally-monophyletic status of Mops condylurus and M. leucostigma. Comorian (Mohéli and Anjouan) and Malagasy M. leucostigma samples formed a monophyletic Mops leucostigma group, within which Comorian samples formed a poorly-supported subclade in the cytochrome b analysis only. Cytochrome b genetic distances of 13.8 % separated M. midas from M. condylurus and M. leucostigma, which formed reciprocally-monophyletic sister groups separated by genetic distances of 2.5 % for cytochrome b and 13 % for the D-loop. 49 M. leucostigma cytochrome b sequences yielded seven haplotypes, two of which were exclusive to the Comoros. D-loop haplotype analysis did not support the distinctiveness of the Comorian samples. Genetic distances within M. leucostigma samples were low (0.22 % for cytochrome b and 1.91 % for the D-loop). Comorian samples were found to be genetically attributable to M. leucostigma. Clear phylogenetic separation between M. condylurus and M. leucostigma was found in all analyses, consistent with their status as phylogenetic species within the genus Mops. There was no clear correlation between haplotype distribution and aspect (east/west-facing slopes), elevation or gender. Low mtDNA variation (cytochrome b and D-loop) and lack of phylogeographic concordance indicates that the observed morphometric variation between eastern and western Mops leucostigma populations may possibly be explained in terms of adaptation to local environmental conditions. / Thesis (M.Sc.)-Univeristy of KwaZulu-Natal, 2008.
4

Comparative behavior and ecology of the family Molossidae in Arizona

Cox, Thomas Joseph, 1933- January 1962 (has links)
No description available.
5

Genetic variability of Chaerephon atsinanana (Chiroptera) within the context of the Afro-Malagasy Molossidae : a mitochondrial and nuclear perspective.

Napier, Melanie Carmel. 25 November 2013 (has links)
This study has focused on genetic variability and structure in Chaerephon atsinanana, a newly-described molossid bat found in the mid to southern region of the eastern watershed of Madagascar. As these bats are strong fliers, and are able to traverse the riverine and mountain barriers within the landscape, it was hypothesized that they would show relatively low levels of intraspecific genetic structure, consistent with patterns shown for other Molossidae on Madagascar (Mormopterus jugularis, Mops midas, Mops leucostigma, and C. lecuogaster. Phylogenetic (neighbor-joining, parsimony and Bayesian inference) and population genetic analyses of maternally-inherited mitochondrial control region sequences revealed the presence of 6 distinct haplotype groups separated by genetic distances of up to 8.14% (mean 4.95%). There were high levels of genetic structure among the haplotype groups (overall FST= 0.994). Thus the hypothesis of low levels of genetic structure was rejected. Bayesian skyline analyses and significantly ragged mismatch distributions were consistent with ancient stable C. atsinanana populations which were of constant size during the last two major Pleistocene glacial periods. This made retreat into and expansion from glacial refugia an unlikely explanation for such high levels of structure. An alternative hypothesis is that C. atsinanana haplotype groups are spatially structured as a result of philopatry. As mitochondria are maternally-inherited, this data is consistent with the existence of female philopatry in C. atsinanana. The second aim of this study was to examine the genetic structure of C. atsinanana with nuclear sequence markers, which are biparentally-inherited, in order to provide information on the male contribution to gene flow and the possible presence of male philopatry in this molossid bat species. The initial objective was to amplify and sequence candidate nuclear markers in order to identify those which were variable among C. atsinanana samples. I attempted to amplify and sequence a set of 12 nuclear markers, identified from the literature, which had been reported to show high levels of variability, or which were untested and showed the potential for high levels of variability. Of these, the intron markers PNPO-3, SLC38A7-8, CARHSP1-1, GAD2-1, OSTA-5 had not previously been used in phylogenetic analyses while FES, GHR, RHO1 CHRNA1, STAT5, PRKC1 and THY had been. I was not able to amplify and/or sequence SLC38A7-8, CARHSP1-1, GAD2-1, OSTA-5, CHRNA1, STAT5 and THY across the range of the C. atsinanana samples. PNPO-3, FES, GHR, RHO1 and PRKC1were successfully amplified and sequenced, but showed no variability and very little polymorphism, and were therefore unsuitable for testing hypotheses related to genetic variability of C. atsinanana populations. These five nuclear sequence markers were further used to investigate phylogenetic relationships among 5 genera (Chaerephon, Mops, Mormopterus, Otomops and Sauromys) and 13 species of Afro-Malagasy molossid bats, and to provide a nuclear phylogenetic perspective on the newly-described C. atsinanana. PNPO-3 is a novel nuclear intron marker, previously unused in phylogenetic studies. This intron provides resolution primarily at the genus level, and is less informative at interspecific level. These five nuclear markers were combined with already existing mitochondrial cytochrome b (Cyt b) and nuclear Rag2 data retrieved from GenBank. This study provides strong support for the monophyly of the Chaerephon and Mops taxa included, with the exception of C. jobimena, which was weakly associated with this group. There was no support for the generic affiliation of C. jobimena or for the monophyly of either of the genera Chaerephon or Mops individually. This leads to the suggestion that Mops and Chaerephon be combined into a single genus, with crown age of 14.82 (6.44-25.54) MYA, or 21.97 (12.16-33.44) MYA if C. jobimena is included. Otomops forms a strongly supported clade consistent with its generic status, comprising two subclades corresponding to the recognised sister species O. martiensseni and O. madagascariensis, which last shared a common ancestor 8.35 (2.87-17.47) MYA. This study provides good nuclear support for the mitochondrially-defined subclades of O. martiensseni, which last shared a common ancestor 4.18 (1.08-9.96) MYA. It would appear appropriate to name the clade from north east Africa and Arabia as a new species of Otomops, as the clade from southern and western Africa includes the type locality. This study provides weak support based on individual gene regions for associations of Sauromys with Otomops and Mormopterus, although these do not stand up in the concatenated datasets which offer better resolving power, indicating that Sauromys is not phylogenetically associated with Chaerephon/Mops, Otomops and Mormopterus. These results provide some support for the membership of Mormopterus in the proposed Old World Molossid tribe, Tadarini, but also support Mormopterus as a basal genus within the Molossidae, consistent with its designation as a separate tribe, Mormopterini. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.
6

Genetic analysis of Chaerephon pumilus (Chiroptera: Molossidae) from southern Africa.

January 2008 (has links)
Chaerephon pumilus, the little free-tailed bat, (family: Molossidae) has a distribution throughout most of sub-Saharan Africa and the eastern region of Madagascar. The vast geographical distribution of this species is accompanied by considerable phenotypic variation, which may conceal cryptic species. The cytochrome b (845 nucleotides) and D-loop (314 nucleotides) regions of the mitochondrial DNA were sequenced to assess phylogenetic relationships within C. pumilus (southern Africa) and in relation to Chaerephon species from Madagascar (C. pumilus, C. leucogaster). Samples were obtained from KwaZulu-Natal, South Africa, and localities in Swaziland. The cytochrome b sample (n = 11) comprised four haplotypes, with a haplotype diversity of 0.6727, whilst the D-loop (n = 34) dataset comprised 13 haplotypes with a haplotype diversity of 0.8342. Neighbour joining, maximum parsimony and Bayesian analyses revealed congruent tree structures for both mtDNA regions. All Chaerephon taxa in this study formed a monophyletic clade with respect to the outgroup Mops midas. Chaerephon pumilus from the eastern side of Madagascar formed a well-supported monophyletic group, sister to a clade comprising C. pumilus (southern Africa) and C. leucogaster, and is suggested to comprise a separate species. Southern African C. pumilus formed two paraphyletic clades, A and B, separated by a genetic distance of 0.9 %. Chaerephon leucogaster formed a monophyletic group nested within southern African C. pumilus, suggesting conspecificity. However, the well-characterized morphology of C. leucogaster lends support to its specific status, and suggests the possible existence of cryptic species among southern African C. pumilus. Population genetic analysis suggests that two C. pumilus (southern African) clades have been expanding, one for between 2432 and 4639 years, and the other for the 11156 to 21280 years. A combined cytochrome b analysis, trimmed to 343 nucleotides, was carried out on the data from this study and that of Jacobs et al. (2004), also on southern African C. pumilus. Haplotypes from the Jacobs et al. (2004) study, which also identified two 0.9 % divergent clades (light- and dark-winged) were found to be identical or very similar to haplotypes from this study and were interspersed among southern African C. pumilus haplotypes in phylogenetic analyses. Chaerephon pumilus haplotypes from Zambia and Tanzania were found to be more closely related to those from southern Africa and to C. leucogaster than to C. pumilus (Madagascar), further indicating that this may be a separate species. Haplotypes from the light-winged clade of Jacobs et al. (2004) were identical to those of dark-winged samples from this study, suggesting that wing shade may not be diagnostic of the two clades. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2008.
7

Operationalizing the telecoupling framework for migratory species using the spatial subsidies approach to examine ecosystem services provided by Mexican free-tailed bats

López-Hoffman, Laura, Diffendorfer, Jay, Wiederholt, Ruscena, Bagstad, Kenneth J., Thogmartin, Wayne E., McCracken, Gary, Medellin, Rodrigo L., Russell, Amy, Semmens, Darius J. January 2017 (has links)
Drivers of environmental change in one location can have profound effects on ecosystem services and human well-being in distant locations, often across international borders. The telecoupling provides a conceptual framework for describing these interactions-for example, locations can be defined as sending areas (sources of flows of ecosystem services, energy, or information) or receiving areas (recipients of flows). However, the ability to quantify feedbacks between ecosystem change in one area and societal benefits in other areas requires analytical approaches. We use spatial subsidies-an approach developed to measure the degree to which a migratory species' ability to provide services in one location depends on habitat in another location-as an example of how telecoupling can be operationalized. Using the cotton pest control and ecotourism services of Mexican free-tailed bats as an example, we determined that of the 16 states in the United States and Mexico where the species resides, three states (Texas, New Mexico, and Colorado) are receiving areas, while the rest of the states are sending areas. In addition, the magnitude of spatial subsidy can be used as an indicator of the degree to which different locations are telecoupled to other locations. In this example, the Mexican free-tailed bat ecosystem services to cotton production and ecotourism in Texas and New Mexico are heavily dependent on winter habitat in four states in central and southern Mexico. In sum, spatial subsidies can be used to operationalize the telecoupling conceptual framework by identifying sending and receiving areas, and by indicating the degree to which locations are telecoupled to other locations.

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