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Thesis (M.S.)--University of North Texas, Dec., 2007. / Title from title page display. Includes bibliographical references.

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Domoic acid (DA) is a neurotoxin produced by the harmful algae Pseudo-nitzschia that has been directly linked to mass stranding events of the California Sea Lion (CSL). The purpose of this paper is to review the anthropogenic influence on the production of this neurotoxin and examine how human activities are impacting this marine mammal species. A comprehensive and interdisciplinary literature review was conducted to evaluate the future sustainability of the CSL population. It was found that while Pseudo-nitzschia bloom developments are vulnerable to anthropogenic influences, the incontestable existence of natural contributing factors adds a certain complexity to the determination of causalities and the development of solutions. Strong evidence exists to show that DA can cause major and irreversible neurological damage in CSLs. Rehabilitation of DA-impacted CSLs is a polarizing issue in the U.S. and presents interesting implications for sustainable development. While the CSL population is currently healthy and plenteous, the strong abundance of future uncertainties warrants concern. A balance must be found between the involving social, economic, and environmental factors to ensure a promising future for the CSL species.

Thesis (M.Int.)--University of Pretoria, 2004. / Title from opening screen (viewed 11 April 2005). Includes summary. Includes bibliographical references.

Plants and wildlife are being affected by climate change and human activities. We need to understand the patterns in these impacts to develop management strategies and policy solutions that will help us conserve ecosystems. Climate change is shifting the timing of key life stages in plants, but we do not fully understand the extent and implications of phenological shifts – or changes in the timing of seasonal events – for understudied stages like fruiting or for potential mismatches between plants in different canopy levels. Human activities and climate change impact and harm wildlife in many ways, from wildlife-vehicle collisions and lead poisoning to hurricanes and infectious diseases, but it has been difficult to form a comprehensive picture of these threats across many species and regions, and to discern which factors pose the greatest threat to at-risk species. Here, I collected and curated data from herbarium specimens and wildlife rehabilitation records to advance our understanding of the effects of climate change and human activities on plants and wildlife in North America. First, I found that metrics of first, peak, and last fruiting dates were strongly correlated between two historical datasets, suggesting that field observations and herbarium collections capture similar orders of fruiting times among plant species in New England. However, I found differences in the exact timing of first and last fruiting dates, indicating that researchers should match methodology when selecting historical records of phenology for present-day comparisons, especially when the exact timing is important. Next, I found that native trees, native shrubs, and non-native shrubs advanced their leaf-out or flowering times faster than native wildflowers advanced their flowering times with warming temperatures. As climate warming progresses, some native wildflower species, especially in warmer regions, are likely to be affected by phenological mismatch and lose access to early-season sunlight. Last, I found that human disturbances accounted for the largest proportion of wildlife injury and sickness in animals admitted to wildlife rehabilitation centers, and I identified the predominant reason for admittance for many species; these reasons included vehicle collisions, fishing incidents, and window or building collisions. I recommended possible interventions to help conserve wildlife, including using or changing wildlife road crossings, fishing and hunting regulations, lead and pesticide regulations, and disaster management plans. In this research, I compiled and analyzed innovative, newly-digitized data sources to provide new insights into the effects of climate change and human activities on plants and wildlife in North America. / 2024-09-18T00:00:00Z

Raptor rehabilitation has become commonplace globally, yet studies on the survival and adaptation of great horned owls (Bubo virginianus) after release has been neglected to an appreciable extent. The primary objective of this study is to provide quantitative data on the success of rehabilitated and released great horned owls in the North Texas region. Owls (N=12) were rehabilitated and released onto the Ray Roberts Greenbelt Corridor in Denton County, Texas, and monitored using radio telemetry to evaluate home range (November 2002 - February 2005). With approximately 75% of the birds released for this study surviving until transmitter battery failure, it is believed that the rehabilitation process was successful for these birds.

Wildlife rehabilitation, defined as “providing temporary care to injured, ill and orphaned wild animals with the goal of releasing them back into their natural habitat”, developed in response to the increase in human population and urbanisation. Widllife rehabilitation centres developed to deal with casualties from man-made hazards; and because rehabilitation involves human emotions of empathy and compassion, the activity has not tended to be the domain of wildlife specialists, but of concerned members of the public. This has caused concerns for wildlife specialists over the welfare of animals being rehabilitated, because making decisions based on emotions may result in an animal being kept alive under unethical conditions, instead of being euthansed. Furthermore, there may be negative impacts on conservation, as it could divert money away from habitat protection and may place wild populations at risk from disease and genetic pollution. This dichotomy in opinion is most often seen between rehabilitators, who focus on the individual animal, and government wildlife officials, who grant them permits, and who focus on the security of entire communities. Although the value of wildlife rehabilitation cannot be underestimated, in terms of its service to wildlife and the public, there is a need to evaluate whether wildlife rehabilitation may result in more rather than less animal suffering and have a detrimental impact on the existing wild populations. I thus set out to determine the efficacy of wildlife rehabilitation, particularly in South Africa. In the first assessment of rehabilitation centres in South Africa, 65% known centres (n = 63) from all nine provinces returned questionnaires. Several thousand injured, diseased and orphaned animals pass through these centres each year, clearly showing the need for rehabilitation centres in South Africa. However, due to lack of scientific research on the efficacy of rehabilitation methods of care and release, and minimal post-release monitoring, I found that experience and intuition drove most rehabilitation practices. Additionally, because personnel from most centres cited lack of finance as a main impediment to the goal of rehabilitation, the result of rehabilitation may include negative affects on individual animal welfare and survival, as well as on conservation efforts for wildlife communities. Thus, I suggested wildlife rehabilitation be centralised to a provincial or national government. Furthermore, I suggested that guidelines of minimum standards should be developed in consultation with experienced rehabilitators, veterinarians and conservation scientists; to be enforced by trained and dedicated conservation officials. To gain further insight into the need for wildlife rehabilitation in a community in South Africa, I decided to examine four-years of intake records from a large rehabilitation centre in the KwaZulu-Natal Province for trends. Animal intake rate was high (2701 ± 94 per annum). Most of the intake (90%) was birds, with few mammals (8%) and reptiles (2%), and most of these were of locally common species (eg doves, pigeons). This reflects the findings of other studies, namely that species living in close association with humans are the most frequently admitted to rehabilitation centres. In total, most of the animals admitted (43%) were juveniles, which were assumed to be abandoned or orphaned. The implications of then rehabilitating these juveniles, which were largely uninjured, is whether humans should be interfering with nature if the cause was not human-related; can each juvenile (especially in these large numbers) be adequately prepared to survive and thrive when released into the wild; and is there space in the environment for them, without causing harm to others already in the environment. I suggest that the large numbers of animals currently being admitted to the centre may be reduced, possibly through increased public education particularly to leave uninjured juveniles in the wild. Furthermore, improvements in the centre’s recording system may allow for use in funding requests and for various research opportunities. There is a general lack of post-release monitoring in wildlife rehabilitation, and the IUCN advises that confiscated and orphaned animals should be euthanased or placed in life-time captivity. I thus decided to document the post-release fate of rehabilitated vervet monkeys and leopard tortoises, two species commonly admitted to a rehabilitation centre, and rock hyrax (Procavia capensis), as a further case study, even though individuals were not from a rehabilitation centre. Success of releasing rehabilitated animals cannot be judged on whether it results in a self-sustaining population, as in reintroductions, as it is to improve the welfare of that particular animal, independent of its species’ status. Survival is thus the most basic indicator of a successful rehabilitation release. Other aspects, such as behaving similarly to a wild animal, are additional success factors, as they likely influence survival. Although after one year post-release, the two troops (T1 = 35, T2 = 24) of vervet monkeys (including an infant) survived, were independent of human food provision and companionship, had established in an area, and had births in the breeding season following release; low known survival (T1 = 11%, T2 = 50%) make it difficult to designate these releases as successful. However, it was clear that the two groups of rock hyrax released were not successful. The group of rock hyrax that had previously been in captivity for 16 months (n = 17) did not have site fidelity after release, and after three months could not be found. All wild rock hyrax (n = 9), except one whose fate is unknown, were found dead, mostly predated, within 18 days. The release likely failed due to predation. For both vervet monkeys and rock hyrax, a lack of social cohesion was suggested as causing the group to dissolve or split upon release, which in turn would increase their vulnerability to predation. Recommendations are provided for considerations in future releases of captive vervet monkeys and rock hyrax. Movements of two groups of tortoises (ten and seven individuals) released at two different sites were monitored over a year, using radio-telemetry. In total, one tortoise was returned to captivity because of disease, four were killed intentionally or accidentally by humans, three others died due to a combination of disease, starvation and/or dehydration, and the fate of six were unknown. Since only two out of seven tortoises survived 13 months after release and only one out of ten tortoises were known to have survived 25 months after release, rehabilitated leopard tortoises were not successfully released into the wild. Recommendations to improve the success of future releases are provided. The occurrence of disease in the tortoise release was a worrying result, and must be addressed before any further releases are allowed. To summarise, there is a dichotomy between wildlife rehabilitation and conservation throughout the world, but this study highlighted the situation in South Africa. The IUCN guidelines for the reintroduction, introduction and supplementation of animals make it clear that there are many threats to the individual animal, to the release environment and to the conservation of species when transporting and releasing animals, especially if they had been in captivity. I believe that I have presented enough evidence in the thesis to suggest that wildlife rehabilitation may result in negative consequences to the welfare of the individual being rehabilitated and to the wild conspecifics or to other species in the release site. I suggest that wildlife rehabilitation needs to move away from being an emotional-based “animal-rights” organisation, to being objectively managed, such that no harm is caused to conservation by these efforts. This may require them to change their constitution so they are aligned with the IUCN guidelines, where more consideration is given to the possible risks involved in releasing animals. However, the applicability of the IUCN guidelines will vary slightly according to the species and situation, and they require input from the local conservation authorities (as was the case in the studies documented in this thesis). I suggest that the public be educated as to the risks that wildlife rehabilitated animals can pose to the safety of the environment as a whole, and that rehabilitated animals do not necessarily survive or thrive in the wild when released, and thus they have to understand that rehabilitation centres will sometimes have to prioritise casualties for treatment, and euthanase exotic species. In conclusion, implementing further research in ensuring long-term post-release survival of rehabilitated animals; developing and enforcing practical guidelines/minimum standards by dedicated and qualified governmental wildlife conservation officials; and having examinations in order to qualify as a wildlife rehabilitator, will ensure humans are “making amends” instead of having an additional negative impact on conservation and animal welfare. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009

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