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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.
101

Aspects of the conservation of oribi (Ourebia ourebi) in KwaZulu-Natal.

Grey, Rebecca Victoria. January 2006 (has links)
The oribi Ourebia ourebi is probably South Africa's most endangered antelope. As a specialist grazer, it is extremely susceptible to habitat loss and the transformation of habitat by development. Another major threat to this species is illegal hunting. Although protected and listed as an endangered species in South Africa, illegal poaching is widespread and a major contributor to decreasing oribi populations. This study investigated methods of increasing oribi populations by using translocations and reintroductions to boost oribi numbers and by addressing overhunting. Captive breeding has been used as a conservation tool as a useful way of keeping individuals of a species in captivity as a backup for declining wild populations. In addition, most captive breeding programmes are aimed at eventually being able to reintroduce certain captive-bred individuals back into the wild to supplement wild populations. This can be a very costly exercise and often results in failure. However, captive breeding is a good way to educate the public and create awareness for the species and its threats. Captive breeding of oribi has only been attempted a few times in South Africa, with varied results. A private breeding programme in Wartburg, KwaZulu-Natal was quite successful with the breeding of oribi. A reintroduction programme for these captive-bred oribi was monitored using radio telemetry to assess the efficacy of such a programme for the oribi. As with many reintroductions of other species, this one was not successful and resulted in many mortalities. However, many variables have been identified that contributed to the failure of this programme and they can be adapted to increase the chances that captive breeding and reintroduction be a viable conservation tool for oribi. Besides captive breeding and reintroductions, the translocation of wild animals can also be effective in sustaining wild populations. Translocations usually appreciate a higher rate of success than reintroductions. A translocation of wild oribi was attempted in this study. This involved the translocation of four males and eleven females and a year-long monitoring programme. This translocation proved to be extremely successful in establishing a sustainable wild population of oribi with few mortalities and several births. However, such translocations can only be attempted when there is suitable habitat and high security from poaching. One source of oribi for the translocation part of the study was from a housing estate that had a high density population of oribi. The existence of such a thriving population of animals on what is often a controversial type of development led to a case study investigation. Housing developments are increasing in size and in numbers in South Africa, and are rarely held accountable for the destruction caused to local habitat or wildlife. This case study used this housing estate as an example of development and conservation cooperating and enjoying the success of a thriving population of endangered oribi. Many variables have been identified that contribute to the success of this venture and that could be used as a requisite for planned housing developments in the future. In particular, clustering of houses to leave open wild areas that are managed ecologically. Finally, the issue of illegal hunting was identified as a very serious threat to oribi conservation. Using surveys, residents of rural settlements and landowners were probed about this issue so that a demographic profile of hunters could be created. This profile could then be used to make recommendations on ways to slow the spread of illegal hunting as well as educate hunters and conservation laws. The results showed that many rural people hunt on a regular basis and most hunt with dogs. It also III showed that there is a high level of ignorance amongst these people on the laws concerning conservation and wildlife species. It was concluded from this study that captive breeding and reintroduction of oribi might be a way to enhance wild populations, but might be more useful in creating public awareness. Translocation, on the other hand, was extremely successful as a way of saving doomed populations and augmenting stable ones. However, it requires suitable and protected habitat. Using housing estates as havens for endangered species is an option but only if the right legislation is passed and cooperation demanded with large portions of land remaining undeveloped. Addressing illegal hunting is the most important, and possibly the most difficult hurdle for oribi conservation besides habitat destruction. Finally, recommendations for oribi conservation and management were made based on the results from this study. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
102

Lions on small reserves : an evaluation of ecological impact and financial viability

Erasmus, Wayne Norman 31 July 2008 (has links)
A founder population of lion (Panthera Leo) was introduced into a 70 km² privately-owned, wildlife reserve in the Waterberg area of South Africa. The lion and prey species' populations were monitored between 2001 and 2004. In this period, 452 kills were recorded at a mean kill rate of one kill every 2.43 days. The lions killed 11 common prey species. Eland, warthog, kudu, wildebeest and zebra comprised 75 % of the lion's diet. The lions consumed an average of 8 % of the available common prey species population per annum. Initially, the mean ungulate population growth rate was 30.9 %, but this rate declined to -0.8 % during the study period. Significantly more animals were killed in open habitats than in closed habitats. The loss in game value for the study period was over one million Rand. A formula was compiled to quantify the cost versus return aspects of introducing lion. / Nature Conservation / M. Tech. (Nature Conservation)
103

The restoration potential of fynbos riparian seed banks following alien clearing

Vosse, Shelly 12 1900 (has links)
Thesis (MScConsEcol(Conservation Ecology and Entomology)--University of Stellenbosch, 2007. / Riparian areas are highly complex systems with varying levels of disturbance that are highly susceptible to invasion by alien plants. Once invaded, riparian areas play a major role in the dispersal and spread of invasive alien plants (IAPs) through the river system and, in some cases, to neighbouring landscapes. Riparian areas have therefore been prioritized by many alien clearing initiatives in South Africa. Current practice for the restoration of cleared areas is minimal and relies mainly on the un-aided recovery of native species from residual individuals and soil stored seed banks. Little research, however, has been done on the effectiveness of this approach or the extent to which riparian seed banks contribute towards community restoration. This study is part of a national research initiative (Targets for Ecosystem Repair in Riparian Ecosystems in Fynbos, Grassland and Savanna Biomes) funded by Department of Water Affairs and Forestry, in collaboration with Working for Water, The Centre for Invasion Biology and the Universities of Cape Town, Stellenbosch, Rhodes and Witwatersrand. The initiative undertook to investigate different restoration techniques on various invaded sites for their cost-effectiveness, efficiency, practicality and conservation integrity. This study has three aims. The first is to determine the composition of seed banks in un-invaded riparian areas within the fynbos biome to be used as a benchmark for future research, restoration grading and other management requirements. The second aim is to determine the composition of seed banks in heavily invaded riparian areas, and thus to assess the impact of invasion on the integrity of the seed banks. The third aim is to evaluate the restoration potential of riparian seed banks following the clearing of invasive alien plants (IAPs). Study sites were selected within four river systems in the south-western part of the Western Cape Province in South Africa: the Berg, Eerste, Molenaars and Wit Rivers. Plots were selected in both invaded (>75% IAP canopy cover; considered “closed” alien stands) and un-invaded (also termed reference, with <25% IAP canopy cover) sections of the river. Replicate plots were established along varying gradients of elevation (mountain stream and foothill) and moisture regimes (dry, wet and transitional bank zones). Soil samples were collected together with above-ground vegetation surveys and comparisons were made. Results from this study confirm those of previous studies that seed banks offer little reference to current aboveground vegetation, but rather offer insight into past vegetation history as well as future vegetation assemblages. Worldwide, many of the species that characteristically form seed banks are early successional species. A community study was done for the seed bank based on the species that germinated and were identifiable at termination of the project (6 months after initiation). Three clusters of species could be identified. One group comprised 32 generalist species that occurred in both reference and invaded sections of the rivers. A second group comprised 39 species associated with invaded sites, and a third group of 40 species that was associated with reference sites. A few sub-community groups were found within both the “reference” and “invaded” community groups which were assumed to be habitat specific. Most species were “pioneer” or relatively-short lived, early-successional species which play a vital role in the initial post-disturbance vegetation cover, and facilitate establishment of later successional species. Seed banks are notoriously variable over space and time, and floristic representation is often biased as a result of differences among species in seed production, dispersal and longevity in the soil. The general consensus is that seeds have an irregular, clustered spatial distribution that is dictated by both biological and environmental factors. Within river systems, the irregular clustering can be exceptionally skewed with the influence of pockets of high sediment deposition along the bank. Environmental factors that were found to significantly skew germination results were the presence of fire, as well as the extent and intensity of invasion (duration and cover). The high level of diversity and abundance in reference Berg River mountain stream seed banks was perceived to be a direct result of a moderate fire frequency (between 8-15 years) and the relatively natural state of the vegetation (i.e. very little invasion). Also, diversity and richness of indigenous species from the Wit and Molenaars Rivers were substantially higher in the invaded samples than the reference samples, probably because both river systems have a long history of invasion and other anthropogenic disturbances which would have an effect on the samples from “reference” sections (i.e. even a 25% presence of IAPs seems adequate enough to alter the composition of the seed bank). Correspondence analyses showed that species had clear affinities towards different levels of “key” riparian environmental variables (fire, invasion and anthropogenic disturbance). Most species were associated with moderate levels of fire frequency, invasion history, and anthropogenic disturbance. Comparisons of seed bank species assemblages between the lateral and longitudinal variables of the rivers offered insights into the habitat requirements of certain fynbos and riparian species. Most significant were the results from bank zone comparisons which showed distinct species groupings along the different moisture bands. As could be expected, riparian species were best represented within the wet bank zones and fynbos species within the dry bank zone, while species characteristic of both zones occurred in the transitional zone, making this seed bank zone the richest in species. Mountain stream sections were richer and more diverse than foothill sections over both invaded and reference samples. This is hypothesised to be linked to lower levels of anthropogenic disturbance experienced in the mountain stream sections. The impact of invasion on the riparian seed bank was most clearly shown through the correspondence analyses for the 20 most frequently occurring species. The seed bank assembly patterns were clearly defined by the state of the river (reference or invaded). Interestingly, this pattern was evident at all three spatial scales; landscape (rivers), reach (mountain stream and foothill sections) and habitat (dry, wet and transitional zones). The reference seed bank assemblage was more tightly grouped, implying that the species were more closely associated with each other and less variable than those of the invaded seed bank assemblages. The species groupings within the invaded seed banks were influenced by variables such as reach and zone, whereas the reference seed bank assemblages seem relatively unaffected by these variables. This implies that the presence of invasive alien plants creates additional variation within the seed bank which alters the natural groupings. At a broad scale, the invaded seed banks were less species rich. This means that not only will the resulting seedling community be harder to predict, but it will also have fewer species. However although generally lower in species richness, the seed banks from almost all invaded rivers interestingly showed a higher diversity of indigenous species than their reference counterparts. This is very promising in terms of rehabilitation of post-cleared riparian sites, but more information is needed to understand the seed bank composition and determine how sustainable the seed banks are for rehabilitation in the long-term. All invaded sections had fewer herbaceous perennial species but more herbaceous annual species. Graminoids made up 50% or more of the seed bank regardless of state (reference or invaded), while woody species (shrubs/shrublets) were generally more prevalent in the reference samples. These results imply that following the removal of invasive alien plants, the vegetation to regenerate from the seed bank is likely to comprise of short-lived, herbaceous species that are not necessarily an accurate reflection of the indigenous riparian community. It is however important to note that this study investigated only the species that were able to germinate over the study period (6 month germination period). Many riparian species may not have been represented because they are either late germinators or may not be present in the soil seed bank at all. In order to gain a holistic understanding of riparian community recruitment, it is recommended that seed bank studies such as this one be included in a more broad scale, long term investigation which takes into account various reproductive strategies used by riparian species. Research of this nature is in its infancy worldwide and there are many challenges involved in measuring diversity and change in these systems. However, within the scope of this study, I suggest that these results shed light on previously unanswered and important questions regarding the ecology of seed banks in the riparian ecosystems of the Western Cape.
104

Closure of the Umlazi landfill : meeting statutory requirements for engineering and plant cover.

Mannie, Neeraj Mannie. January 2008 (has links)
This study investigated the establishment of vegetation cover planted in plug and seedling form in the closure phases of the Umlazi Landfill. It also investigated the various facets of the closure process of the Umlazi Landfill and the effect these have on the establishment and choice of vegetative cover, and the grass technology used to make the establishment of vegetation a success. The setting up of trials and the gathering of basic data were undertaken to assess the alternative vegetation options available to researchers. The cover provided by the grasses was assessed in the investigation. The capping of landfill sites is a relatively new approach and it is soon to become a mandatory requirement by the Department of Water Affairs and Forestry (Minimum Requirements for Waste Disposal) (DWAF, 1998). This systematic investigation used in the closure of the Umlazi Landfill, will provide a model for the capping of landfills in South Africa. Seeing that this was the first hazardous (H:h) landfill site in the country to be closed according to the Minimum Requirements for Waste Disposal (DWAF, 1998), every attempt was made to ensure that all aspects in the closure of the site met with the Minimum Requirements. The Minimum Requirements document mentions only briefly that the landfill must be vegetated with some grass type. Prior to 1994, capped landfill sites were usually planted with traditional grass seed mixes and these were not widely successful, as seen on many older landfills that have been partially or completely capped, and where vegetation cover is sparse. There is much literature in the developed countries on the closure of landfills (e.g., Erickson, During the site inspections in June 2001 and February 2002, it was noted that many species of alien plants had established themselves in the poor soil conditions. This made it even more important to find indigenous vegetation to vigorously establish itself that would prevent the establishment of alien invaders. Samples of grass species established on some part of the site were also taken for identification. The dominant grass was identified as Cynodon dactylon. In view of establishing a balanced vegetative cover on top of the Umlazi Landfill, Acacia karoo trees (in seedling form) were also planted. Three bunch grass species, Melinis nerviglumis, Melinis minutiflora and Hyparrhenia hirta, were tested to see if thatching grass could be grown on the site to generate a cash crop for local residents of Umlazi township. Preparation and planting of the capped areas took place in the latter part of 2003 and were completed in early 2004. Measurements and field data were recorded and statistically analysed. The trials revealed three key findings: Firstly, both creeping grasses studied, namely Cynodon dactylon var. “Sea Green” and Panicum natalense var. ”Natal Buffalo Grass” grew well on the site. Initially P. natalense grew faster but after a month, C. dactylon overtook it. At the end of the trial (six months, P. natalense provided a higher level of soil cover. However, C. dactylon grew more consistently over this period. Hence both species provided good growth and cover on this site. Secondly the three bunch grasses, Melinis nerviglumis, Melinis minutiflora and Hyparrhenia hirta, all grew well and had similar survival rates. Hence the potential for growing these grasses as a cash crop has potential. Thirdly, all the Acacia karoo trees survived, i.e., they achieved 100% survival. The average height increase and stem width was similar in all trials and growth was consistent over the six month growing period. Hence the tree species would be a good choice for planting on landfills in its ecologically suitable zones. It is therefore feasible to envisage the planting of a mixture of grasses under the cover of A. karoo trees, to provide a balanced mixture of indigenous grasses to cover a freshly capped landfill. Such a system should provide for stable growth of vegetation for many years. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008
105

The management of free-ranging lions on enclosed protected areas.

Kettles, Ross. January 2007 (has links)
This Research investigates the potential impacts that free-ranging lions have within a small (<100 000 hectare), enclosed protected area, and it also investigates the subsequent challenges to the managers of areas such as these. A comprehensive literature review reveals that the smaller the protected area, the more intensively it needs to be managed via active adaptive management, because perimeter fences do not allow for immigration and emigration. The consequences of this are over-population; inbreeding depression; the decline of prey and other predator species; conflict with neighbouring communities as a result of break-outs; and, in some cases, the spreading of intra- and interspecies disease. Lions are very proficient breeders and, in all cases investigated, reserves exceeded their local carrying capacity within a relatively short period of time. A range of management interventions can potentially achieve short- and/or long-term reserve objectives. These interventions include relocation, contraception, hunting and artificial takeovers. These interventions are described in terms of the preparation required, the biological consequences and the sociological influences. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.
106

Lions on small reserves : an evaluation of ecological impact and financial viability

Erasmus, Wayne Norman 31 July 2008 (has links)
A founder population of lion (Panthera Leo) was introduced into a 70 km² privately-owned, wildlife reserve in the Waterberg area of South Africa. The lion and prey species' populations were monitored between 2001 and 2004. In this period, 452 kills were recorded at a mean kill rate of one kill every 2.43 days. The lions killed 11 common prey species. Eland, warthog, kudu, wildebeest and zebra comprised 75 % of the lion's diet. The lions consumed an average of 8 % of the available common prey species population per annum. Initially, the mean ungulate population growth rate was 30.9 %, but this rate declined to -0.8 % during the study period. Significantly more animals were killed in open habitats than in closed habitats. The loss in game value for the study period was over one million Rand. A formula was compiled to quantify the cost versus return aspects of introducing lion. / Nature Conservation / M. Tech. (Nature Conservation)
107

Ověření úspěšnosti předchozího vysazení raka říčního a revize výskytu raka pruhovaného na území CHKO Třeboňsko / Verification of success of previous noble crayfish introduction and revision of occurrence of spiny cheek crayfish in the CHKO Třeboňsko

KOUTNIK, Dalibor January 2013 (has links)
The aim of this thesis was to verify the success of previous reintroduction of noble crayfish (Astacus astacus) in main streams and selected reservoirs in the protected area Třeboňsko. Further expansion took place monitoring invasive signal crayfish (Pacifastacus leniusculus) and spiny cheek crayfish (Orconectes limosus) in these streams. Both are a carrier of crayfish plague. Thus, where they already exist, would not make sense to try to strengthen further the population of noble crayfish.
108

The feasibility of reintroducing African wild dogs (Lycaon pictus) into the Great Fish River Nature Reserve, Eastern Cape, South Africa

Page, Samantha Karin January 2014 (has links)
With a declining population of roughly 3000-5000 individuals in Africa, African wild dogs (Lycaon pictus) are one of the most endangered carnivores in the world. As the global human population expands, it is becoming increasingly unlikely that large portions of land will be set aside for conservation, especially in developing countries. Thus, recent wild dog conservation efforts in South Africa have concentrated on establishing a managed metapopulation. A metapopulation is a group of geographically isolated subpopulations of a species that are managed (using supplementation and harvesting) to mimic natural gene flow. The Great Fish River Nature Reserve (GFRNR) in the Eastern Cape Province of South Africa has been identified as a potential reserve to become part of the national wild dog metapopulation. My research aimed to conduct a feasibility assessment of the long-term (~ 25 years) success of a wild dog reintroduction into the GFRNR. This assessment included biological modelling of wild dogs and their expected prey, and determining the potential anthropogenic threats to wild dogs on the private and communal land surrounding the reserve. I used VORTEX population modelling and determined that the GFRNR is likely to have a wild dog carrying capacity of ~22 individuals. Using a 25-year modelling simulation, the most appropriate wild dog reintroduction scenario would be to reintroduce six females and four males initially and supplement the population with one female and two males in years 3, 10, 15 and 23. In addition, the harvesting/removal of one male and one female in years 10 and 20 would be required to ensure 100% population persistence and adequate genetic diversity. Kudu (Tragelaphus strepsiceros) and bushbuck (Tragelaphus scriptus) are expected to be the two most important prey species for reintroduced wild dogs in the GFRNR. Furthermore, wild dogs are likely to prefer the north-western and south-western sectors of the reserve because of the relatively high prey densities in these areas. However, regular monitoring of both the potential prey and the wild dog populations is essential to ensure persistence of the wild dogs and to prevent prey populations decreasing precipitously. Using structured questionnaire interviews (n = 128), I found that while neighbouring land owners and local communities were generally positive about the potential wild dog reintroduction (56 % of all respondents), several threats to wild dogs were identified along the reserve boundary and on the adjoining unprotected land. Some private landowners and members of rural communities around the reserve (34 %) stated that they would kill any wild dogs that dispersed onto their land. In addition, some respondents (8 %) admitted to believing in traditional uses for wild dog products (e.g. fur) which could result in the illegal killing of wild dogs outside of the GFRNR for traditional purposes. Poaching and the presence of unvaccinated domestic dogs on neighbouring land were also identified as being potential threats to a reintroduced wild dog population. However, such anthropogenic threats appear to be localised to the western and southern boundaries of the reserve. Therefore, by implementing preventative measures (such as anti-snare collars, anti-poaching patrols and vaccination against rabies and canine distemper) the likelihood of such threats occurring can be reduced. I conclude that the GFRNR can sustain a population of wild dogs and successfully contribute to South Africa‘s national metapopulation. An additional reserve will benefit the country‘s metapopulation by increasing the number of wild dogs available for translocation, thereby increasing genetic diversity and overall resilience (to environmental change, disease etc.) of South Africa‘s wild dog population. This will contribute towards the future conservation of this endangered species.
109

MODELING THE POTENTIAL FOR GREATER PRAIRIE-CHICKEN AND FRANKLIN’S GROUND SQUIRREL REINTRODUCTION TO AN INDIANA TALLGRASS PRAIRIE

Zachary T Finn (11715284) 22 November 2021 (has links)
<p>Greater prairie-chickens (<i>Tympanuchus cupido pinnatus</i>; GPC) have declined throughout large areas in the eastern portion of their range. I used species distribution modeling to predict most appropriate areas of translocation of GPC in and around Kankakee Sands, a tallgrass prairie in northwest Indiana, USA. I used MaxEnt for modelling the predictions based on relevant environmental predictors along with occurrence points of 54 known lek sites. I created four models inspired by Hovick et al. (2015): Universal, Environmental, Anthropogenic-Landcover, and Anthropogenic-MODIS. The Universal, Environmental, and Anthropogenic-MODIS models possessed passable AUC scores with low omission error rates. However, only the Universal model performed better than the null model according to binomial testing. I created maps of all models with passing AUC scores along with an overlay map displaying the highest predictions across all passing models. MaxEnt predicted high relative likelihoods of occurrence for the entirety of Kankakee Sands and many areas in the nearby landscape, including the surrounding agricultural matrix. With implementation of some management suggestions and potential cooperation with local farmers, GPC translocation to the area appears plausible.</p> <p>Franklin’s ground squirrels (<i>Poliocitellus franklinii</i>; FGS) have declined throughout a large portion of the eastern periphery of their range. Because of this, The Nature Conservancy is interested in establishing a new population of these animals via translocation. The area of interest is tallgrass prairie in northwest Indiana, USA: Kankakee Sands and the surrounding landscape. Species distribution modelling can help identify areas that are suitable for translocation. I used MaxEnt, relevant environmental variables, and 44 known occurrence points to model the potential for translocation of FGS to Kankakee Sands and the surrounding area. I created four models inspired by Hovick et al. (2015): Universal, Environmental, Anthropogenic-Landcover, and Anthropogenic-MODIS. I created maps of models with passing AUC scores. The final map was an overlay map displaying the highest relative likelihood of occurrence predictions for the area in all passing models. Only the Universal and Anthropogenic-MODIS models had passable AUC scores. Both had acceptable omission error rates. However, none of the models performed better than the null model (p < 0.05). MaxEnt predicted that a few areas in and outside of Kankakee Sands possess high relative likelihoods of occurrence of FGS in both the Universal and Anthropogenic-MODIS models. However, MaxEnt predicted high relative likelihoods in the surrounding agricultural matrix in the Universal Model. FGS prefer to cross through agricultural areas via unmowed roadside instead of open fields (Duggan et al. 2011). Because of this, high predictions in agricultural matrices in the Universal model are irrelevant. High relative likelihood predictions for linear sections that are obviously roads are disregardable in the context of my modeling efforts. Because of my low sample size, none of the models are really reliable in predicting relative likelihoods of occurrence for this area. Despite high relative likelihood predictions, the appropriateness of a translocation effort to the area is inconclusive.</p>
110

Population dynamics and population genetics of the Critically Endangered Raso lark : implications for conservation

Dierickx, Elisa Gwenda Godelieve January 2018 (has links)
The Raso lark is a Critically Endangered bird endemic to the islet of Raso, Cape Verde. This thesis investigates two phenomena that particularly put the species at risk: its extreme fluctuations in population size, and its potentially very low genetic diversity arising from small population size and severe past population contraction. More specifically, two chapters estimate year-to-year survival and explore the factors - environmental and individual - that influence it, while two other chapters examine the lark’s genetic characteristics compared to its two continental closest relatives, including phylogenetic relationships and levels of genetic diversity. The conclusion of the thesis then uses these results to make recommendations for the conservation of the Raso lark. Each of the data chapters is summarized below: Chapter 3 estimates adult survival in the Raso lark and tests whether it could be linked to two population phenomena observed in the field: a highly variable population size and a male-biased sex ratio in certain years. Using a dataset spanning 10 years, I estimated survival for both sexes to fluctuate between 0.76 and 0.94 over this period. This is much higher than the survival rate of its closest relative, the skylark. I also found strong evidence for survival fluctuating over time and differing between males and females (with males having higher survival until 2011, at which point the trend inverted), which could play a role in the aforementioned population size fluctuations and male-biased sex ratio, respectively. Chapter 4 aims at understanding which factors shape survival in the Raso lark. Two types of variables were considered: year-dependent (rainfall, population size, population mean clutch size) and individual-dependent (age, body size characters, size ratio with mate, Ase18 genotype). Amongst the year-dependent variables, only sameyear rainfall impacted survival, with a 13% decrease in survival in the wettest year compared to the driest year, making it the most likely explanation for the inter-annual fluctuations in survival found in Chapter 3. Results also hint at some of the individual factors - morphological measurements and Ase18 genotype - influencing survival. The picture that emerges is that of a species whose life history strategy is to invest heavily in maintenance and survival, but less into fecundity, which stands in sharp contrast with the mainland-dwelling skylark. This is consistent with the theory that island birds generally have slower life history strategies than their continental counterparts. Chapter 5 determines the precise relationship between members of the Alauda clade, resolving a node on the phylogenetic tree of all larks that the study by Alström et al. (2013) was unable to resolve. My RADseq results indicate that the Raso lark and the skylark are sister species, and that the Oriental lark is likely to be a subpopulation, or maybe a subspecies, of the skylark. Chapter 6 compares the population genetics of the Raso lark with those of the skylark. In particular, it estimates the genetic diversity of the Raso lark and investigates the drivers behind it. I found unexpectedly high nucleotide diversity in the Raso lark, and explain this by showing that the population contraction that the species underwent was recent enough for most of the diversity to still be present. Moreover, 16% of the Raso lark genome has levels of heterozygosity on average 6.6 times higher than elsewhere on the genome, likely due to suppressed recombination and the existence of a neo-sex chromosome in larks. Despite this, I found high levels of relatedness and of linkage disequilibrium in the Raso lark, two clear genetic signs that it underwent a severe population contraction several centuries ago.

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