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Climate change and endangered species in Canada: A screening level impact assessment and analysis of species at risk management and policyLundy, Kathryn N. January 2008 (has links)
Climate is a long-term driver of ecological change, but the rapidity with which climate is projected to change over the next century may push the limitations of ecological adaptability, to the detriment of biodiversity. Given their typically small populations, limiting biological traits and exposure to external stressors, species currently classified as “at risk” may be among the most vulnerable to climate change and least capable of adapting naturally. A screening level assessment of the impacts of climate change on endangered species in Canada was conducted by integrating knowledge of the current status and characteristics of each endangered species with projections of climate change and climate change impacts. It was determined that climate change may have a potential overall negative influence on more than half of all endangered species in Canada. However, while relatively few species were predicted to respond in an overall positive or neutral manner to climate change, a large portion of endangered species were classified as having insufficient information to generate a decision on the net influence of climate change; in many cases, these species were located at the northern extent of their range in warmer regions of Canada and have the potential to experience at least some benefits under climate change provided that other stressors are sufficiently mitigated. These results, as well as the inherent vulnerability of species at risk to environmental change, the potential for species at risk distributional shifts and the likelihood of increasing rates of species imperilment, demonstrate the need for greater consideration of the implications of climate change in species at risk management and policy. Canada’s Species at Risk Act (SARA) does not explicitly address the issue of climate change and limitations exist in SARA’s time-sensitive definition of wildlife species eligible for protection in Canada and in the interpretation of SARA’s mandates in the context of anthropogenically driven climate change. It is recommended that climate change be systematically considered in all species at risk assessments, recovery strategies and management plans and that SARA’s definition of a wildlife species be revaluated in light of shifting species distributions under climate change. Further recommendations to identify “values” that will assist in prioritizing species for conservation, to reassess the concept of an invasive species under climate change and to implement strategies that focus more broadly on the conservation of biodiversity and ecological integrity rather than individual species may require ethically complex discussions and decisions on the part of species at risk managers and policy makers. Future research should focus on informing species at risk management and policy by improving modeling capabilities at the species level, conducting in-depth analyses of priority species, and building knowledge of alternative species conservation strategies such as assisted colonization.
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Climate change and endangered species in Canada: A screening level impact assessment and analysis of species at risk management and policyLundy, Kathryn N. January 2008 (has links)
Climate is a long-term driver of ecological change, but the rapidity with which climate is projected to change over the next century may push the limitations of ecological adaptability, to the detriment of biodiversity. Given their typically small populations, limiting biological traits and exposure to external stressors, species currently classified as “at risk” may be among the most vulnerable to climate change and least capable of adapting naturally. A screening level assessment of the impacts of climate change on endangered species in Canada was conducted by integrating knowledge of the current status and characteristics of each endangered species with projections of climate change and climate change impacts. It was determined that climate change may have a potential overall negative influence on more than half of all endangered species in Canada. However, while relatively few species were predicted to respond in an overall positive or neutral manner to climate change, a large portion of endangered species were classified as having insufficient information to generate a decision on the net influence of climate change; in many cases, these species were located at the northern extent of their range in warmer regions of Canada and have the potential to experience at least some benefits under climate change provided that other stressors are sufficiently mitigated. These results, as well as the inherent vulnerability of species at risk to environmental change, the potential for species at risk distributional shifts and the likelihood of increasing rates of species imperilment, demonstrate the need for greater consideration of the implications of climate change in species at risk management and policy. Canada’s Species at Risk Act (SARA) does not explicitly address the issue of climate change and limitations exist in SARA’s time-sensitive definition of wildlife species eligible for protection in Canada and in the interpretation of SARA’s mandates in the context of anthropogenically driven climate change. It is recommended that climate change be systematically considered in all species at risk assessments, recovery strategies and management plans and that SARA’s definition of a wildlife species be revaluated in light of shifting species distributions under climate change. Further recommendations to identify “values” that will assist in prioritizing species for conservation, to reassess the concept of an invasive species under climate change and to implement strategies that focus more broadly on the conservation of biodiversity and ecological integrity rather than individual species may require ethically complex discussions and decisions on the part of species at risk managers and policy makers. Future research should focus on informing species at risk management and policy by improving modeling capabilities at the species level, conducting in-depth analyses of priority species, and building knowledge of alternative species conservation strategies such as assisted colonization.
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Conservation of Antillean manatees in the Drowned Cayes area of BelizeSullivan, Caryn Self 15 May 2009 (has links)
The purpose of this study was to determine how manatees use Swallow Caye, Drowned
Cayes, and Gallows Reef, three distinct habitat types within the Belize Barrier Reef
lagoon system near Belize City. Data were collected using boat-based point scan
methods with the assistance of volunteers. Presence/absence and photo ID methods
ensured consistency of data collection despite a changing pool of volunteer researchers.
Results confirmed the mangrove and seagrass ecosystem between the Belize Barrier
Reef and Belize City as important manatee habitat. Inconsistent with the prevailing
"seasonal distribution hypothesis" for manatees in Belize, the probability of
encountering manatees at Swallow Caye and in the Drowned Cayes was equal between
dry and wet seasons. However, manatees were only observed at Gallows Reef during
the wet season. Swallow Caye had the highest probability of encountering manatees,
confirming traditional knowledge held by local tour operators, which led to the
establishment of Swallow Caye Wildlife Sanctuary in 2002. In contrast to previous
studies, my data suggest that at least 44% of the manatee population carry scars from
non-lethal boat strikes. The proportion of scarred animals did not vary as a function of
habitat type, season, or year. The probability of encountering manatees did not change between years, despite an exponential increase in cruise ship tourism. Marine Protected
Areas (MPAs) and wildlife protection laws indicate that Belize is working to meet
obligations under international agreements. However, there is still cause for concern.
Manatees do not remain inside designated refuge boundaries; governmental agencies
depend on co-management agreements with local non-governmental organizations for
enforcement of rules inside MPAs; regulations governing human behavior outside MPAs
are lacking; funds for monitoring and evaluation of MPAs are lacking. Manatee
conservation strategies should be integrated into a system of riverine, coastal, and
marine protected areas supported by additional tactics such as required manatee training
for boat captains, slow zones at hot spots outside MPAs, and continued educational
outreach. With few modifications and increased enforcement and monitoring, the Belize
model for manatee conservation could lead to a shared "triumph on the commons" for
the manatees and the user groups that shared their habitat.
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Modeling aspects of the ecological and evolutionary dynamics of the endangered Houston toadSwannack, Todd Michael 15 May 2009 (has links)
The goal of my dissertation was to describe the dynamics of a group of Houston toads located at the Griffith League Ranch (GLR), Bastrop County, Texas. My research included using statistical modeling to predict activity and abundance, mark-recapture techniques to estimate survivorship, and simulation modeling to explore the impacts of the difference in age at first reproduction and to project the future dynamics of the population at the GLR. From 2001 – 2005, 225 individual Houston toads (199 M : 26 F) were captured using two methods: breeding pond surveys and drift fences. Houston toads were neither caught equally among capture methods, nor across years. Toad activity was mostly confined within their breeding season, and activity was not continuous. A logistic regression indicated activity depended on time of year, mean precipitation, mean minimum daily temperature, and mean percent lunation as well as two-way interactions with moon-phase and other variables. Abundance depended on time of year, current precipitation, minimum temperature, and two-way interactions between time of year and the other two variables. Twenty-one of the 199 males (10.5%) and no females were recaptured among years. The probability of male survival was estimated using program MARK. Eight of 16 candidate models were supported and all but one contained precipitation as a covariate, indicating precipitation is important for Houston toad survival. Survivorship estimates varied from 0.1 to 0.41. The sex ratio was significantly male-biased. The odds of catching females in traps were 3.5 greater than capturing females in a pond, while the odds of capturing males in a trap were 0.28 compared to ponds. Results from a simulation model indicated the sex ratio is biased because of the difference in maturation times between males and females, coupled with high juvenile mortality. Results from an individual-based, spatially-explicit, stochastic simulation model, indicated a relatively low probability (~ 0.013) of B. houstonensis going extinct at the GLR within the next 10 years. Emergent properties of the model were similar to results observed in the field or reported in the literature. The model also identified that dispersal of Houston toads should be a future research priority.
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Metapopulation Ecology and Recovery of the Endangered Lower Keys Marsh RabbitSchmidt, Paige McGee 2009 December 1900 (has links)
The Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri), a
subspecies of marsh rabbit endemic to the Lower Keys, Florida, is threatened with
extinction due to extensive coastal development of salt marsh habitats. LKMR recovery
is limited by habitat loss and degradation from brush encroachment, predation by freeroaming
cats (Felis catus) and raccoons (Procyon lotor), sea-level rise, and hurricanes.
This study sought to determine local and landscape factors that influence LKMR
metapopulation ecology and dynamics and to evaluate strategies for their recovery. I
evaluated the influence of patch and landscape characteristics on LKMR densities,
extinction, and colonization rates following Hurricane Wilma, and the response of
LKMRs and salt marsh habitats to prescribed fire. I used estimates of population change
based on annual monitoring data to validate vital rates, constructed a spatially explicit
demographic model to evaluate various levels and spatial configurations of recovery
scenarios implemented throughout the LKMRs range, and validated expected changes in parameter estimates using measures of habitat degradation and raccoon activity from
known LKMR populations.
I found LKMR densities were higher in patches with greater numbers of
bunchgrasses and forbs and less edge and lower in patches with higher measures of
raccoon activity. In response to a hurricane, I found the distance between LKMR
patches and the coast had a negative influence on extinction probability; the distance
between an extirpated and occupied LKMR patch had a negative influence on
colonization probability and patch size had a positive influence. Adult LKMRs
increased as woody cover <0.5 m decreased, herbaceous cover <0.5 m increased, and
food availability increased in at least one site following prescribed fire. Model results
indicated habitat management actions that improve carrying capacity of local rabbit
populations and juvenile survival and control raccoon populations to increase rabbit
reproductive rates are effective population recovery strategies. In total, my results
provide a conservation planning tool that can be used to select recovery strategies and
locations that will maximize benefits to LKMRs, thus improving their viability and
recovery.
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The winter ecology of piping plovers (Charadrius melodus) along the Texas Gulf Coast /Zonick, Curtis A. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 162-168). Also available on the Internet.
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Tools for managing threatened species : improving the effectiveness of whio conservation : a thesis submitted for the degree of Doctor of Philosophy in Ecology at the University of Canterbury /Whitehead, Amy. January 2009 (has links)
Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (p. 121-138). Also available via the World Wide Web.
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Rapid endangered species assessment : a novel approach to improve extinction risk assessments in poorly known species /Bianchi, Carlos A. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 155-180). Also available on the World Wide Web.
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Restoration of endangered epiphytic lichens in fragmented forest landscapes the importance of habitat quality and transplantation techniques /Lidén, Marlene, January 2009 (has links) (PDF)
Diss. (sammanfattning) Umeå : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.
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Golden-cheeked warbler nest predators and factors affecting nest predation /Stake, Mike M. January 2003 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references. Also available on the Internet.
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