[Truncated abstract] Amidst concern over the global phenomenon of declining amphibians, there is an increasing appreciation of the importance of understanding population dynamics at both local and regional scales. Data on the viability and persistence of species in landscapes altered by humans are scarce but an understanding of these dynamics is essential for enabling long-term species conservation in a modified world. Habitat loss, fragmentation and ensuing salinisation are of particular concern for species in Australia’s temperate agricultural regions where the rapid conversion of continuously vegetated landscapes to small fragments has occurred in less than 200 years. This thesis investigated the local and metapopulation structure of Heleioporus albopunctatus to determine the current population structure and likely future of this species in a highly degraded landscape: the wheat and sheep growing areas of southwestern Australia ... The life-history attributes of H. albopunctatus, including high fecundity, high adult longevity and low to moderate dispersal contribute to a robust regional metapopulation, responsive to changes, but with a strong chance of persistence over the long-term. H. albopunctatus appears to have adjusted to a radically modified landscape but its long-term persistence may be dependent on the existence of a small number of source populations that recruit in most years.

The conservation of aquatic-breeding amphibian populations and their habitats is increasingly challenged by urban and rural development, which is occurring more intensively and more rapidly than ever before. Some species are now impacted by development throughout their range. This has forced a re-evaluation of the potential of developed landscapes for providing habitat and contributing to regional conservation strategies. For many amphibians, little is known about the criteria necessary for persistence in a developed landscape. Considerable variation in the physiology, habitat requirements, and movement behaviour of amphibians suggests that responses to habitat loss, alteration, and fragmentation are species-specific. In this thesis, I investigate species-habitat relationships for the northern red-legged frog (Rana aurora) and the Pacific chorus frog (Pseudacris regilla) in a mixed urban-rural landscape in southwestern British Columbia to evaluate the potential for species persistence despite urban and rural development throughout their range. I used repeat auditory surveys of the species’ breeding chorus to determine presence or absence at potential breeding wetlands. I then related species occurrence and abundance to characteristics of the aquatic and terrestrial environment measured at multiple spatial scales. Both species were found to use rural and urban wetlands, though R. aurora were rarely detected while P. regilla were common. Occurrence was best explained by characteristics of the terrestrial environment, rather than within-wetland characteristics, though influential terrestrial characteristics and their scale of impact differed between species. Within the context of the developed landscape, I identify species-specific positive and negative habitat associations and suggest the spatial scales at which management of these habitat characteristics will be most effective. These criteria may help to explain the species’ current distribution, prioritize management strategies, predict the effectiveness of habitat conservation and restoration projects, and inform development in municipalities seeking to maintain or enhance amphibian diversity. / Graduate / 2019-09-11

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Quantitative relationships between blood flow velocity, vessel diameter, width of the peripheral plasma layer and induction of thrombus formation were studied in small blood vessels of the retrolingual membrane and intestinal mesentery of the frog, Rana Pipiens, and of the cheek pouch of the golden hamster, Mesocricetus auratus. Blood flow velocity was measured by a modification of the technique described by Hugues (Arch. Int. de Physiol. 61: 565, 1953). Internal vessel diameters and widths of the total peripheral plasma layer were measured with an ocular micrometer. Thrombus thresholds were determined by graded electrical stimulation. Determinations were made on 202 vessels in retrolingual membranes of frogs prepared by single pithing. In 95 arterioles (diameters from 10 to 40 microns), the mean flow velocity was 2.84 mm/sec. and the mean volume flow rate, 1.68xl0-3 cu mm/sec. The mean width of the total peripheral plasma layer was 3.6 microns and its ratio to mean vessel diameter was 1:6. In 107 venules (diameters from 10 to 50 microns), the mean flow rate was 1.20 mm/sec. The mean volume flow rate was 1.02x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 4.1 microns and its ratio to mean vessel diameter was 1:7.4. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.3 and 1:1.6 respectively. Measurements were made on 100 mesenteric vessels of frogs prepared by single pithing. In 50 arterioles (diameters from 15 to 45 microns), the mean velocity was 3.77 mm/sec. The mean volume flow was 3.05xlo-3 cu mm/sec. The mean width of the total peripheral plasma layer was 2. 7 microns and its ratio to mean vessel diameter was 1:11.5. In 50 venules (diameters from 20 to 50 microns), the mean velocity was 1.55 mm/sec. and the mean volume flow rate, 1.76x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 6.7 microns and its ratio to mean vessel diameter was 1:5.3. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.3 and 1:1.7 respectively. A total of 109 mesenteric vessels were studied in frogs anesthetized with urethane. In 55 arterioles (diameters from 15 to 45 microns), the mean velocity was 3.28 mm/sec. The mean volume flow was 2.87x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 3.2 microns and its ratio to mean vessel diameter was 1:9.3. In 54 venules (diameters from 20 to 50 microns), the mean flow rate was 1.61 mm/sec. and the mean volume flow, 1.83x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 5.6 microns and its ratio to mean vessel diameter was 1:5.9. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.0 and 1:1.5 respectively. In these three series of studies in the frog, no relationship was clearly apparent between velocity and either vessel diameter or width of the peripheral plasma layer in arterioles. Suggestions of a direct relationship between velocity and peripheral plasma layer in veins, however, were evident. In all cases, and in both arterioles and venules, vessel diameter and peripheral plasma layer were clearly and directly related. The effects of flow velocity changes on width of the total peripheral plasma layer in individual vessels were studied in 26 arterioles of the hamster cheek pouch. Blood flow was varied by means of a cuff described by Copley (Biorheology 1: 3, 1962). A direct relationship between velocity and width of the peripheral plasma layer was clearly demonstrated. Thrombus thresholds were determined in mesenteric vessels of the frog. In 103 arterioles (diameters from 20 to 140 microns), the mean strength of stimulus necessary to produce a platelet thrombus was 24.8 volts with an amperage of 0.18 milliamperes. In 100 venules (diameters from 20 to 140 microns), the mean strength of stimulus necessary was 20.7 volts with an amperage of 0.12 milliamperes. Possible relationships of thrombus thresholds to flow velocity in mesenteric arterioles and venules are discussed. / 2031-01-01

Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-09Bitstream added on 2014-06-13T18:08:07Z : No. of bitstreams: 1 mansano_cfm_me_jabo.pdf: 502787 bytes, checksum: 5bc0cd3d3cea43c0c800c012a6d4f886 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Melhorias no manejo alimentar devem ser implementadas na ranicultura, visando diminuir os efeitos indiretos da alimentação inadequada, resultando em melhores taxas de crescimento e deposição de nutrientes, consequentemente obtendo animais de melhor qualidade. O objetivo do presente estudo foi estabelecer curvas de crescimento morfométrico de girinos de rã-touro e sua deposição de nutrientes na carcaça. Foram utilizados 6.480 girinos de rã-touro no estágio 25 de Gosner, alimentados com dieta experimental (26,23% PD – 32,68 PB) e comercial (37,92% PB), oferecida “ad libitum. O modelo utilizado para descrever a curva de crescimento foi de Gompertz. Os girinos alimentados com a dieta experimental, além de apresentarem uma deposição protéica final maior, o modelo sigmoidal apresentou-se muito mais homogêneo, mostrando uma taxa de deposição protéica diária mais constante. O modelo de Gompertz apresentou um ótimo ajuste para descrição da curva de crescimento morfométrico e deposição de nutrientes na carcaça para girinos de rã-touro, mostrando que os girinos alimentados com a dieta experimental, apresentaram melhor taxa de crescimento e deposição de nutrientes na carcaça / Improvements in food handling must be implemented in frog culture in order to reduce the indirect effects of inadequate nutrition, resulting in better rates of growth and deposition of nutrients, thus obtaining better quality animals. The objective of this study was to establish morphometric growth curves of bullfrog tadpoles and deposition of nutrients in the substrate. We used 6480 of bullfrog tadpoles in stage 25 of Gosner, fed experimental diets (DP 26,23% - 32,68 CP) and commercial (37,92% CP) offered ad libitum. The model used to describe the curve of growth was the Gompertz. Tadpoles fed the experimental diet, in addition to having a higher final protein deposition, the sigmoidal model presented is much more homogeneous, showing a daily protein deposition rate constant. The Gompertz model showed a good fit for describing the growth curve morphometric and deposition of nutrients in the substrate for bullfrog tadpoles, showing that the tadpoles fed the experimental diet showed better growth rate and deposition of nutrients in the substrate

Circuits underlying motor patterns of closely related species provide an ideal framework in which to study how evolution shapes behavioral variation. Male African clawed frogs (Xenopus and Silurana) advertisement call to attract female mates and silence male rivals. Males of each species produce a unique vocal pattern that serves as a species-identifier. Xenopus laevis is the most well-studied species in terms of its vocal behavior and underlying anatomy and physiology. The clade that includes X. laevis, or X. laevis senso lato, also includes 3 other species that diverged ~8.5 million years ago. All 4 of these species produce advertisement calls that include fast trills – trains of fast rate (~60 Hz) sound pulses. However, their calls differ substantially between species in measures of trill duration and period. I examined the premotor circuit underlying vocal patterning in three of these species: X. laevis, X. petersii, and X. victorianus. I used extracellular recordings to find that a premotor nucleus, DTAM, which is part of the vocal central pattern generator, is the likely source of species-variation of vocal patterns. Species-specific trill duration and period are intrinsic to the region of the hindbrain that includes DTAM. Next, I used blind whole-cell patch recordings in DTAM of X. laevis and X. petersii to examine the cells that encode trill duration and period. I identified homologous populations of premotor vocal cells in both species that code for trill duration and period in a species-specific manner. Together, these results support an autonomous role of the DTAM circuit for generation of species variation in call duration and period.

The introduction of a species to areas outside its native range can result in ecological and genetic changes of evolutionary significance. The frog Eleutherodactylus coqui was introduced to Hawaii, from Puerto Rico, in the late 1980s and has lost genetic variation in mitochondrial DNA. The extent to which founder effects have influenced phenotypic variation in the introduced range is unknown. In this study I compared phenotypic variation in life-history traits, advertisement calls, and stripe patterns among introduced and native populations of the frog Eleutherodactylus coqui. I also conducted laboratory experiments to determine the influence of genetics and temperature on trait variation. Body size in wild populations was positively correlated with elevation in both ranges, but the slope of elevation on body size was greater in Puerto Rico than in Hawaii. Advertisement call frequencies and rates were negatively correlated with elevation but duration was positively correlated with elevation. Frequencies were correlated with body size, but rate, duration, and intensity were not. Color patterns are more variable in Puerto Rico than Hawaii and appear to be maintained by balancing selection in Puerto Rico. Lab results indicate that body size is negatively correlated with temperature, which may explain Bergmann's rule in the field, but patterns of intrinsic growth rate may explain differences in the effect of elevation between Hawaii and Puerto Rico. Body size appears to explain most of the variation in call frequencies, whereas temperature explained most of the variation in rate and duration. Color patterns appear to be determined by a single locus with five alleles. Founder effects appear to explain the difference between Hawaii and Puerto Rico in color pattern variation and in clinal variation in body size and call frequencies. The loss of genetic variation in these traits is likely to have evolutionary consequences for this species in Hawaii.

A primary goal of population genetics is to identify the role of microevolutionary forces in producing observed patterns of molecular and phenotypic variation. I conducted four studies in the northern leopard frog, Rana pipiens, to determine just how mutation, migration, genetic drift, and selection influenced, genetic structure of mitochondrial DNA (mtDNA), nuclear DNA, and a single locus polymorphism that determines dorsal coloration. In the first study, I surveyed the literature concerning color and pattern polymorphisms in anurans. I conclude that anuran polymorphisms remain a rich but largely unexploited system for studying the evolution of phenotypic variation in nature. In the second study, I compared mitochondrial DNA variation from 35 populations distributed across the species' range. A phylogenetic analysis indicated R. pipiens is split into two deeply divergent mtDNA groups, a western group and an eastern group. Phylogeographic and demographic analyses indicated that although restricted gene flow with isolation by distance explained the majority of the processes influencing current genetic structure, population bottlenecks and expansions also played an important role. In the third study, I investigated mtDNA and microsatellite variation in Pacific Northwest populations of R. pipiens, where a recent range contraction had occurred. I found that peripheral populations had reduced levels of genetic variation compared to more interior populations. Moreover, I found that historic samples from peripheral population already had reduced levels of genetic variation. Therefore, low diversity in the remnant populations could not be ascribed to the recent range contraction. In the fourth study, I compared genetic structure from a suite of putatively neutral molecular markers with that derived from the color polymorphism locus. Genetic structure at the color locus, assessed both spatially and temporally, was indistinguishable from structure at neutral loci. This study exemplifies the importance of investigating for evidence of selective maintenance before studies attempt to measure the selective mechanisms maintaining a polymorphism. Overall, my research helps to elucidate how biogeographic and microevolutionary forces influence a wide-spread North American species, R. pipiens. / Graduation date: 2004

In species where males do not provide immediate benefits to females in the form of resources or parental care to offspring, adaptive mate choice may be maintained by selection because preferred males sire offspring that are genetically superior. I test the hypothesis that female mating preferences result in enhanced performance of their larvae, owing to genetic variation among sires in two species of red-eyed treefrogs. This variation in males may be manifested as body size or in advertisement call parameters. I examined natural pairing patterns and found that both species display a size-based mating pattern with substantial seasonal effects. In lean years, females mate with males that are larger on average, yet females also seem to favor a constant size ratio of the male relative to her body size. I documented significant call trait variation both within and among males and have evidence to support size-related call traits as indicators of mating success for some properties. Finally, I provide evidence for a pronounced effect of sire size on offspring traits, most notably upon hatching that may have significant post-metamorphic fitness benefits. My study provides data on the basis of female choice and may provide a link between female preference for male traits and enhanced offspring performance by larvae sired by preferred males in the evolution of anuran mating systems.

The purpose of this study was to provide a model for teachers for the use of the oral tradition of the Indian in local history courses.<p>The study was based on two basic premises: that the Indian side of history is neglected in Canadian history books and school textbooks and that the Indian oral tradition is as valid an historical source as the traditional documentary evidence.<p>The Frog Lake Massacre, an incident during the Riel Rebellion in which eight white residents of Frog Lake were killed by some of the followers of Big Bear's band, was chosen to demonstrate this model. The Indian story of the Frog Lake Massacre has not been told in history books. Thus, it was proposed that the oral tradition for this event be traced, recorded and preserved for this study. Since the people involved in the Frog Lake Massacre fled from the area at the time of the troubles, three areas were chosen where it was suggested that there might be descendants of the people from the Frog Lake area. These were: Onion Lake Reserve and Poundmaker Reserve in Saskatchewan and Rocky Boy Reservation in Montana.<p>The selection of the Elders who could provide the information was left to the director of the Saskatchewan Indian Cultural Centre, Smith Atimoyoo, and the Chippewa-Cree Research team at Rocky Boy. These people have been involved in cultural retention programmes and have familiarity with the various Elders and their expertise. For the purpose of this study, one Elder was chosen from each area -- Mrs. PeeMee (Poundmaker), Mr. Four Souls (Rocky Boy), Mr. Francis Harper (Onion Lake).<p>After the initial contact was made through the intermediaries, the researcher was introduced and the intent of the research explained, a time and place was arranged for the taping of the tradition.<p>In preparation for the interviews, an extensive study was made of the literature on the oral tradition and in particular the oral tradition of the Cree. Further consultations with Smith Atimoyoo provided invaluable information on the position of the Elders and how someone should approach them when requesting their help.<p>Four Souls was taped in his home by members of the Chippewa-Cree Research team, Mrs. PeeMee was interviewed in the home of her grandson in Saskatoon. Mr. Francis Harper was recorded in a field near his grandson's farm on Onion Lake Reserve.<p>A search of the literature revealed very little work on the collection and preservation of the oral tradition on Native North Americans. Vansina, working in Africa, examined oral traditions and devised certain criteria for testing their validity as historical sources.<p>The collected stories met the criteria for reliability -- the right of the person to tell that story.<p>In applying Vansina's criteria -- the characteristics of the historian himself i.e. who he was, his acculturation level, reaction to the researcher; characteristics of the tradition i.e. origin, type and transmission; the cultural environment i.e. cultural value of the tradition, purpose and function; mnemonic devices -- it was revealed that each historian fulfilled the criteria in a similar fashion. The only difference appeared in the purpose for telling the story. The more traditional Mrs. PeeMee told her account simply to remember and let her grand-daughter relive it with her. Francis Harper and Four Souls expressed a desire to right some of the stories which they had heard and considered untrue.<p>The study revealed that there is a Cree oral tradition concerning the Frog Lake Massacre. Three people from three separate areas covering over 500 miles gave essentially the same story with only differences in emphasis and perspective. Each account must be considered as a unique historical document for this event. Thus, the study showed there was an Indian oral tradition alive in Saskatchewan which is accessible and can be validated as historical evidence within its own frame of reference.<p>Suggestions were made for ways in which teachers could utilize this untapped resource without exploiting it.

This thesis investigated multispectral detection of the invasive floating macrophyte, European Frog-bit, using Quickbird imagery and fuzzy image classification. To determine if the spectral signature of European Frog-bit were separable from other wetland vegetation, a species level land cover classification was conducted on a 6km section of the South Nation River in Ontario, Canada. Supervised and unsupervised imagery classification approaches were evaluated using the fuzzy classifiers, Fuzzy Segmentation for Object Based Image Classification (FS) and Fuzzy C-Means (FCM). Both approaches were sufficiently robust to detect European Frog-bit. User’s and producer’s accuracies for the European Frog-bit class were 81.0% and 77.9% for the FS classifier and 63.5% and 73.0% for the FCM classifier. These accuracies indicated that the spectral signature of EFB was sufficiently different to permit detection and separation from other wetland vegetation and fuzzy image classifiers were capable of detecting EFB in Quickbird imagery.