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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.
11

The Lower Keys marsh rabbit and silver rice rat: steps toward recovery

Perry, Neil Desmond 30 October 2006 (has links)
Extensive development has destroyed and fragmented wildlife habitat in the Lower Florida Keys. The Lower Keys marsh rabbit (LKMR; Sylvilagus palustris hefneri) and the silver rice rat (SRR; Oryzomys argentatus) are listed by the United States Fish and Wildlife Service (USFWS) and the Florida Fish and Wildlife Conservation Commission (FFWCC) as endangered species. Both species depend on coastal prairies, freshwater marshes, and intertidal salt-marsh zones. The objective of this study was to meet specific, species-level recovery goals and to add reliable information that may modify or support current recovery plans. Specifically, I (1) evaluated the use of LKMR reintroduction to suitable habitat, (2) examined characteristics of habitat used by LKMR, and (3) surveyed the Lower Florida Keys for SRRs, documenting current range and examining survey results for the past decade. I reintroduced 7 rabbits (3 males, 4 females) to suitable habitat on Water Key, and monitored their survival and release-site fidelity. All reintroduced rabbits survived and some reproduced, suggesting these translocation techniques are a viable tool for recovery. On Boca Chica Key, I radio-collared 13 LKMRs and compared vegetation characteristics between core-use and avoided areas within home ranges. Binary logistic regression associated rabbit use with high vegetation heights (7–8 dm), low canopy coverage (<=10%), high bunchgrass densities (2.5–3.8/sq m), and forb presence (>5%), supporting the hypothesis that LKMRs may be detrimentally impacted by hardwood encroachment into salt-marsh habitats. For LKMR recovery, I recommend management to resist hardwood encroachment, together with active predator control. I surveyed 36 locations on 18 islands for SRRs, capturing rats on 12 islands, including 2 on which SRRs had not previously been found. Comparisons of my data with historic data suggest SRRs either have increased in abundance over the past decade or that previous trapping efforts were not effective. Abundance of SRRs does not appear to be significantly different from that of populations of rice rats on the mainland. The USFWS and FFWCC should consider revising the conservation status of the SRR; however, it still should be regarded as a unique evolutionary unit with a very limited potential range.
12

Effects of captivity and implications for ex-situ conservation : with special reference to red panda (Ailurus fulgens)

Jule, Kristen January 2008 (has links)
This PhD thesis aims to improve the ex situ conservation of threatened and endangered species by investigating the effects of captivity and improving the methodology of current conservation techniques. The use of reintroduction as a tool for the purpose of conserving species is becoming increasingly popular. Since many wild populations are declining, captive-bred stock are frequently used to restore or supplement wild populations. Evidence suggests that captive-bred animals are less successful than their wild counterparts, but this has not been recently reviewed and there is limited research into investigating what aspects of captivity may be affecting success. Here, I conduct a review of carnivore reintroductions for projects carried out post 1990, which shows that captive-born animals are less likely to survive a release into the wild than their translocated wild-caught counterparts. A case study species, the endangered red panda (Ailurus fulgens), is used to investigate how a species involved in captive breeding for conservation responds to life in captivity. Results from analyses of lifetime reproductive success (and related variables) showed that both adaptation to captivity and inbreeding depression are occurring in the global captive red panda population. An investigation into behavioural adaptation to captivity was less revealing, although only generations three to seven from the wild were observed. The effects of captive environment and husbandry regime were also investigated and revealed that the size of the useable area and amount of human contact were among the factors influencing the behaviours of red pandas. How these findings contribute to a greater understanding of effects of captivity is discussed. The use of selection criteria based on temperament was also investigated in order to improve the likelihood of survivorship upon release into the wild. This method needs to be tested in practice, but based on the selection criteria used, there was evidence that unsuitability for release was positively predicted by generation time in captivity. Implications for the future use of captive red pandas in efforts to conserve the species in the wild are discussed, as well as how these findings can be utilised for other species involved in conservation efforts.
13

The first reintroduction of the western barred bandicoot (Perameles bougainville) to mainland Australia.

Richards, Jacqueline Denise January 2005 (has links)
Almost half of the world�s mammal extinctions in the last two hundred years have occurred in Australia (Short and Smith 1994). The western barred bandicoot Perameles bougainville is one of a suite of species that is currently threatened with extinction, surviving only on two islands in Shark Bay, Western Australia. Reintroduction has been used as a tool in conservation biology to assist in the recovery of threatened species, such as the western barred bandicoot. The aims of this project were to 1) successfully reintroduce and establish a free-ranging mainland population of the western barred bandicoot at Heirisson Prong, Shark Bay, 2) contribute information on the biology of the species, its interactions with introduced species, and its likelihood of persistence as a reintroduced population in the longer-term, and 3) to provide recommendations to assist future reintroductions of the species. The first reintroduction of the western barred bandicoot from surviving remnant island populations to the mainland, some 60 years after its apparent mainland extinction, was from Dorre Island to Heirisson Prong in 1995. Animals were translocated initially to a predator-free refuge on Heirisson Prong, and then subsequently released to the 12 km2 peninsula where introduced predators (foxes Vulpes vulpes and feral cats Felis catus) had been controlled, but European rabbits Oryctolagus cuniculus had not. Despite a small founder number and high mortality of free-range bandicoots in the presence of a low-density feral cat population, the bandicoot population successfully established. The reintroduced population of western barred bandicoots provided an opportunity to study the biology of the species, and to compare it with the remnant island populations and other species of Australian bandicoot. Many population parameters were similar between the island and mainland western barred bandicoot populations, as well as between the western barred bandicoot and other bandicoot species, suggesting that the habitat at the reintroduction site is suitable for long-term persistence of the population. However, there were some notable differences. The western barred bandicoot is the smallest extant species of bandicoot, with fewer young per litter than recorded for other bandicoot species, adult sex ratios were closer to parity, animals reached sexual maturity later, and it is the only species of bandicoot where females are larger than males. Home range size is larger also than recorded for other species. Some of these differences may be explained in part by trade-offs between island dwarfism, lactational pressures, and nest defence. The nesting biology of the western barred bandicoot was studied at Heirisson Prong, including during periods of high and low densities of rabbits. Individuals of the species constructed and utilised nests in a similar fashion to other species of Australian bandicoot, nesting amongst litter underneath shrubs. The western barred bandicoot appeared to favour particular shrub species, especially when vegetation condition was poor due to rabbit damage, but displayed flexibility in being able to construct nests under a variety of shrub species where at least some surface litter was present. Grasses were used in nest construction only when rabbit density was low. Nests appear important for protection against temperature extremes and diurnal predators. Vegetation exclosures around three of the shrub species most commonly used by the western barred bandicoot for nest sites (Acacia ligulata, A. tetragonophylla and Melaleuca cardiophylla) were used to examine the impact of rabbits on vegetation on Heirisson Prong. A high-density rabbit population over the summer of 1997/98 caused in a decrease in canopy cover and the death of mature A. ligulata. Subsequent rainfall and low-density rabbit populations allowed A. tetragonophylla shrubs to recover their former structure, and M. cardiophylla to recover, but not to the same degree. The flexibility of western barred bandicoots in use of nest materials and their omnivorous diet may enable the species to survive in the face of habitat modification by rabbits. Population viability analysis was used to examine future options for the recovery of the endangered western barred bandicoot. Biological data from the Dorre Island and Heirisson Prong populations were input to the computer simulation program VORTEX. The western barred bandicoot populations were modelled under a variety of scenarios to examine the possible effects of changes in carrying capacity, founder population size, inbreeding depression, and the occurrence of drought and cat predation as catastrophes, on the probability of population extinction. This analysis highlighted the need for eradication of feral cats, above all other management actions. Cat predation was particularly potent when it acted through high loss of juveniles, as well as adult bandicoots. Predator control is considered critical for the long-term persistence of reintroduced populations of the western barred bandicoot. This study documents the first reintroduction of the endangered western barred bandicoot to mainland Australia. The population had been extant for four years at the completion of data collection for this thesis, in late 1999 and for over eight years at the finalisation of this thesis in July 2004. The knowledge gained from the reintroduction was used to discuss management recommendations and future options for the recovery of the species. The primary concern for reintroductions of this, and other species of bandicoots, remains the control of introduced predators. For long-term persistence of small, isolated populations, such as those of the western barred bandicoot at Heirisson Prong and the Arid Recovery Project at Roxby Downs in South Australia, and the eastern barred bandicoot Perameles gunnii at a range of sites in Victoria, the complete eradication of introduced predators is essential.
14

Post-Release Ecology of Rehabilitated Hoffmanns' Two-toed Sloths in Panamá

Morton, Chelsea Nicole 01 December 2021 (has links)
The field of wildlife rescue and rehabilitation continues to grow as human expansion increases the rate of deforestation in Latin America. Wild animals that are often rescued from becoming orphaned or injured are rehabilitated in captivity until considered suitable for release back into the wild. Sloths (Bradypus spp. and Choloepus spp.) are a common species admitted to rescue centers throughout Latin America due to their poor dispersal abilities and vulnerability to anthropogenic impacts. Post-release monitoring is fundamental in measuring the success of wildlife rescue programs, however, few studies have assessed the outcomes of releasing hand-reared sloths back into the wild. I studied the ecology of rehabilitated and relocated Hoffmann’s two-toed sloths (C. hoffmanni) in central Panamá. My objectives were to: (1) use a soft-release technique to quantify activity budgets of individuals prior to release in the wild, (2) analyze movement trajectories and estimate home range sizes, (3) assess habitat selection, and (4) determine survival rates and causes of mortality for rehabilitated and released two-toed sloths. Eleven two-toed sloths rescued from the wild were hand-reared in captivity for a mean total of 727  193 days (mean  SE value across all sloths) at the Pan-American Conservation Association facilities in Colón Province, Panamá. During 2019-2020, sloths were processed into 2 groups, radiomarked, placed in an outdoor 500 m2 soft-release enclosure for 3 months, and released in nearby Soberanía National Park. I conducted 580 hr of behavioral observations during soft-release to quantify activity budgets for 5 main activity states. A linear mixed model was used to compare two-toed sloth activity budgets in response to sex, age, season (i.e., dry vs. wet), session time (i.e., morning vs. evening) and month. Rehabilitated two-toed sloths spent 80.0% of their time resting, becoming active and more alert in the evening, exhibiting behavioral patterns similar to wild two-toed sloths (as ascertained from existing literature). I used homing to radiotrack two-toed sloths for 210 radio-days during which I used a paired analysis approach to measure tree height, crown height, height to crown base, diameter at breast height, abundance of lianas, canopy depth, and canopy closure at 118 used and random locations. Habitat selection was modeled using conditional logistic regression and movement trajectories were analyzed using ArcGIS. Rehabilitated two-toed sloths traveled shorter distances than wild two-toed sloths, traveling a mean linear distance of 82.3  21.6 m and a mean distance of 25.6  9.5 m between successive locations. Mean home range size for released two-toed sloths was 2.92  1.19 ha with females occupying larger areas than males. I did not find strong evidence of habitat selection; however, rehabilitated two-toed sloths chose trees with a smaller dbh than available. Habitats used by rehabilitated two-toed sloths closely resembled those used by wild two-toed sloths, selecting trees with dense crowns and 50% lianas. Monthly survival for rehabilitated two-toed sloths (0.72  0.14) was low relative to wild sloths, and monthly estimates for males (1.00  0.00) and females (0.44  0.22) did not differ (P  0.30). Eight mortalities were recorded with predation and natural causes being the main causes of mortality. My study provides information that can be useful in evaluating the costs and benefits of sloth rescue and rehabilitation programs throughout Latin America.
15

A genetic assessment of the Blue Iguana Recovery Programme’s success, and prognosis for the species’ future conservation

McKinney, Mallory 07 August 2020 (has links)
In this study, we used ostensibly neutral microsatellite markers to study genetic variance and heterozygosity of endangered Cyclura lewisi during captive management in the Blue Iguana Recovery Programme. We assessed the variation present in the founding population and how genetic diversity changed throughout the past 20 years of management. We also studied how heterozygosity may correlate with fitness through morphometric measures and success of recruitment after release into the wild. While we found a reduction in effective population size, standardized heterozygosity, and fixation indices did not significantly change from the founders to later generations. We found no evidence for inbreeding depression in the captive population but a significant difference in heterozygosity of animals released to the Salina Reserve. Lastly, we found little evidence to support heterozygosityitness correlations using morphometric measures.
16

The reintroduction of silver pheasant Lophura nycthemera in Hong Kong: a feasibility study

Burrows, Stephen W. January 2004 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
17

Möjligheten att återintroducera skogsvildrenen till Sverige : Återintroduktionens påverkan i området mellan Mora, Leksand och Vansbro / The possibility of reintroducing wild forest reindeer in Sweden : Reintroductions impact in the geographical area between Mora, Leksand and Vansbro

Persson, Linn January 2016 (has links)
The purpose of this study was to investigate if Sweden should reintroduce wild forest reindeer (Rangifer tarandus fennicus Lönn) to the Swedish fauna and what conditions there were for a reintroduction to Vildmarksriket between Mora, Leksand and Vansbro. The purpose was also to investigate the impact of the reintroducement of the stakeholders in the area, such as forest owners, farmers, authorities, organizations and local residents. The methods used were a quantitative attitude survey which consisted of questionnaires and qualitative interviews. The interviews were strategically selected and semi-structured. The conclusion of this study was that stakeholders in the area Vildmarksriket have different opinions about the wild forest reindeer. The issue that concern stakeholders the most and that can create anxiety and conflict in Vildmarksriket is whether the wolves and the bears will be affected by wild forest reindeer and how forestry can be affected. Generally there is a positive attitude towards wild forest reindeer, but there is also a strong uncertainty. Wild forest reindeer can affect species and ecosystems in the region, but the effect seems to be small regardless of whether they are negative or positive. Vildmarksriket still has the potential to be a suitable area for wild forest reindeer to be reintroduced. According to the legislation that exists today, Sweden has no direct juridical obligation to reintroduce wild forest reindeer.
18

RECOVERY OF THE EASTERN WOODRAT IN SOUTHERN ILLINOIS: DISTRIBUTION, DEMOGRAPHICS, AND NONINVASIVE MONITORING

Gooley, Aaron Clinton 01 May 2019 (has links)
Woodrats (Neotoma spp.) are imperiled in the north-central and north eastern United States. In Illinois, eastern woodrats (N. floridana) experienced range reductions and population bottlenecks over the past century. Hypothesized reasons for the decline of many woodrat populations that inhabit rock outcrops in the eastern United States include parasitism by raccoon roundworms (Baylisascaris procyonis), hard mast shortages, owl predation, and reductions in crevice availability for nest construction. During 2004-2005, the isolated remnant populations along the Mississippi bluffs in southwestern Illinois were genetically augmented with 47 eastern woodrats from Arkansas and Missouri resulting in 40% admixture within the largest population. In 2009, a strong windstorm created canopy gaps and woody debris throughout this area, potentially improving habitat for eastern woodrats. During 2003–2009, 422 eastern woodrats were reintroduced to 5 sites in the southeastern Illinois, and 172 eastern woodrats to 2 southern Illinois state parks during 2013–2014. These reintroductions are the only woodrat reintroductions to date with >50 individuals released per site. Most previous woodrat reintroduction attempts have released small numbers of individuals (10–15 per site and 10–54 total) and either failed to establish populations or required frequent management for populations to persist. My objectives were to (1) investigate the status of augmented eastern woodrat populations in southwestern Illinois, (2) evaluate the success of the southern Illinois reintroductions, (3) investigate whether eastern woodrats demographics within a reintroduced metapopulation could be predicted by factors underlying hypothesized reasons for woodrat declines, and (4) develop and evaluate noninvasive alternatives to live-trapping and sign surveys for monitoring woodrat populations.
19

Tamanho populacional, razão sexual e uso do habitat por uma população de mutum-do-sudeste (Crax blumenbachii Spix, 1825) reintroduzida em Ipaba, MG / Population size, sex ratio and habitat use of a Red-billed Curassow (Crax blumenbachii Spix, 1825) population reintroduced in Ipaba, MG, Brazil

Araujo, Joana Carvalhaes Borba de 25 September 2015 (has links)
A fragmentação e a redução do habitat são as principais causas do declínio populacional e de biodiversidade no mundo, seguidas pela sobrecaça. Essas perturbações levaram a família Cracidae ao posto de família de aves mais ameaçada das Américas. Diversos programas de reintrodução já foram conduzidos com cracídeos no Brasil, a começar pela reintrodução do mutum-do-sudeste (Crax blumenbachii Spix, 1825) na Fazenda Macedônia (FM) em Ipaba, MG. O objetivo deste trabalho foi estimar o tamanho e a densidade populacional e a razão sexual dos mutuns existentes na FM e analisar o uso da paisagem pela espécie. Os dados foram coletados ao longo de 6 meses por transecção linear (esforço amostral: 280 km) e analisados segundo protocolos de amostragem por distância linear e ocupação. O tamanho populacional foi estimado em 34 (10 111) indivíduos e a densidade em 2,36 (1,58 7,79) indivíduos/km². Entretanto, a proporção de área utilizada foi estimada em 21%, indicando que a densidade para as áreas realmente ocupadas pode ser mais alta. A intensidade de uso da área parece estar correlacionada principalmente à densidade do sub-bosque e à oferta de suplementação alimentar. A taxa de crescimento populacional foi estimada em -0,047 (-0,137 0,018), o que indica um declínio. É possível que este declínio esteja ligado ao tamanho reduzido da população, que a torna mais susceptível à estocasticidade demográfica, ambiental e genética e ao efeito Allee. Os mesmos fatores também podem estar provocando um desvio na razão sexual, estimada em 0,35 (0,20 0,47). / Fragmentation and habitat loss are the two main causes of population and biodiversity decline, followed by overhunting. Such impacts made the Cracidae family the most endangered bird family in American continents. In Brazil, many reintroduction programs focused on cracids. The first one reintroduced the Red-billed Curassow (Crax blumenbachii Spix, 1825) in Ipaba, MG, Brazil. This work aimed to estimate the population size and density, the sex ratio and the landscape use of the Red-billed Curassow population reintroduced in Ipaba. We collected the data along 6 months through line-transects, totalizing 280 km of effort. The analysis followed distance sampling and occupancy protocols. We estimated the population size in 34 (10 111) birds and the density was 2.36 (1.58 7.79) birds/ha. However, we estimated the proportion of area effective used in 21%, what means that the density for such area might be higher. Apparently, the intensity of habitat use is mostly correlated to the understory density and to food supplementation. We estimated the population growth rate in -0.047 (-0.137 0.018), what indicates a decrease. Its possible that the population is declining due to its size, once small populations are more likely to suffer because of demographic, environmental and genetic stochasticity and Allee effect. The same factors might explain the skewed sex ratio, estimated in 0.35 (0.20 0.47).
20

PLANNING THE REINTRODUCTION OF THE CLOUDED LEOPARD (NEOFELIS NEBULOSA) TO TAIWAN: AN ASSESSMENT OF ATTITUDES AND POTENTIAL SUPPORT

Greenspan, Evan 01 December 2018 (has links)
Large felid populations are in decline globally and wildlife managers have increasingly used reintroductions as a conservation tool, yet few studies have assessed public attitudes towards potential large felid reintroduction candidates prior to release. The clouded leopard was recently declared extinct in Taiwan; however, a reintroduction effort is ecologically feasible and success largely depends on resident attitudes towards clouded leopards and support for its reintroduction. In 2017, 263 semi-structured interviews with indigenous locals were conducted in southern Taiwan and an internet questionnaire was distributed to 500 urban residents for comparison. Rural and urban attitudes were 67% and 76% positive toward clouded leopards, respectively. Males, younger respondents, and residents with more clouded leopard knowledge exhibited more positive attitudes among rural respondents. In addition to these predictors, urbanites with more household children were more positive. Rural support for reintroduction to the Tawushan Nature Reserve was 48% positive, 31% neutral, and 21% opposed, while urban support was 71% positive, 22% neutral, and 7% opposed. Environmental group membership, increases in attitudinal positivity, and lower levels of risk perception and knowledge influenced support for reintroduction in both samples. Although support is substantial among urbanites, a knowledge-based education campaign that targets women and older residents living adjacent to the reintroduction site would benefit reintroduction efforts.

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