While a decrease of wild felid population has led to disruption of conservation programme, recent studies have shown the importance of immune regulation for determining health outcomes and co-infection. Immunoglobulin G is important for detecting and evaluating responses to infectious diseases and vaccination. But, there is limited information on felid immunoglobulins and their role for functional immunity. This study aimed at isolating and characterizing lion’s immunoglobulin G. Lions’ sera (n = 68) were processed using the MagReSyn® magnetic beads and the final protein concentration was determined using the Xpose™ Trinean Spectrophotometer. The cross-reactivity of goat anti-cat immunoglobulin with sera of lions and other species was analysed using ELISA. High cross-reactivity was observed in lions ranging from 87.7 to 100%, and low reactivity with rhino (22.4%) followed by chicken (0.01%). The protein concentration from purified sera yielded 39.09 mg/ml. Molecular weight of lion IgG 150-160 kDa was detected with both chains at 54-56 kDa and 24-26 kDa on SDS PAGE. These results indicate a potential aid in developing serological tools to monitor exposure to micro-organisms of lions. / Agriculture and  Animal Health / M. Sc. (Agriculture)

Large carnivores are in decline throughout their range primarily due to anthropogenic influences. This is a concern because these species have high social, economic and ecological value. African lion (Panthera leo) populations are in decline in most parts of the continent and this has been attributed largely to habitat loss, habitat fragmentation, wire snare poaching, black market trafficking in lion parts, retaliatory killings, and poorly regulated trophy hunting. In order to implement effective lion conservation actions, the effect of each factor on lion demography or population dynamics must be well understood. In the past, most studies have used indirect methods to quantify the effects of hunting on lion demography. The temporary ban on lion hunting in Zambia allowed me to study directly how removing a key source of mortality, for males in particular, changed the demography. Using data collected from 2008-2015, I studied how the lion population in and around South Luangwa National Park, Zambia responded to a 3-year moratorium on lion trophy hunting implemented in 2013. For the duration of the study ban, I monitored 386 known individuals in 19 prides and 15 male coalitions. Reproductive activity as represented by cub production appeared to improve after the hunting ban and the number of individually identifiable lions in the study area steadily increased from 88 in 2008 to 197 in 2015. Using a Cormack-Jolly-Seber model, I found that apparent annual survival increased in the absence of hunting for all adult male age classes. The temporary ban on hunting was lifted in 2016 and I recommend that quotas remain conservative in order to allow more time for the population to recover, particularly in the adult male age classes. Better monitoring protocols should also be implemented to promote compliance with hunting regulations.

thesis submitted to the School of Animal, Plant and Environmental Sciences, Faculty of Science, University of the Witwatersrand, Johannesburg in fulfillment of the requirements for the degree of Masters in Science. Johannesburg 2016. / The Okavango Delta in northern Botswana contains the largest, unfenced lion population in southern Africa, and is one of the most important population strongholds for the species on the continent. Despite its conservation importance, however, little information has been published on the drivers of lion ecology in this unique wetland ecosystem. In the Okavango Delta, the annual flood pulse causes dramatic seasonal contractions of available dry land, and consequently variable distribution and abundance of prey. Lions must therefore adapt to a dynamic environment not only on an annual basis, but also on a longer time-scale as inundation patterns cycle from periods of low to high floods. The main aim of the study was to determine which social and ecological factors were most important in determining lion population demographics and social organisation in the unique wetland environment of the Okavango Delta. Data were intensively collected on demographic rates and social organisation of five resident lion prides in the south-western Okavango Delta from 1997 to 2004, during which inundation patterns shifted from low to high floods. We investigated the effects of two ecological factors, namely prey availability and flood extent, and one social factor, namely intra-specific competition, on lion social organisation and population demographics. Lions occurred at high densities, and the population was regulated socially and not by resource limitation. Our results indicated that competition with neighbours exerted the most extensive influence on the lion population and significantly affected the survival of young cubs and reproductive rates. Competition reduced pride size, but contrary to our expectations, also negatively influenced sub-group size, indicating that territorial disputes do not drive sub-group patterns in the Okavango Delta. Prey availability did not appear to be an important limiting factor for the population, and group sizes were inversely related to prey availability, most likely due to habitat saturation resulting in higher levels of recruitment. Prey availability only influenced survival of young cubs, which are most vulnerable to nutritional stress. Higher levels of flooding led to smaller pride and sub-group sizes, indicating that higher flood levels for extended periods may lead to a decline in lion densities due to increased competition for available dry land. While flooding exerted no direct effect on demographic rates, we posit that habitat conversion during high flood cycles causes a decline in prey, resulting in a time-lagged effect on the lion population. Our results show that during low flood cycles when herbivore abundance is high, lions occur at high densities and are largely self-regulated. However, as flood levels increase, prey availability declines and lions are placed under increasing pressure for space and resources, which could ultimately lead to population decline. From a conservation perspective, the south-western Okavango Delta population is thus most vulnerable during periods of high floods, when lion densities naturally decline, and lions may be pushed towards the veterinary fence where human-lion conflict is high. Future studies should focus on how anthropogenic threats around the Okavango Delta threaten the viability of the lion population in this conservation area, and seek to secure important corridors to neighbouring populations. Keywords: lion, Panthera leo, social organisation, pride size, population demographics, survival reproduction, Okavango Delta, flooding, competition, prey abundance / LG2017

Studies of predator-prey and predator-predator interactions are needed to provide information for decision-making processes in land management agencies. Mountain lions (Puma concolor) are opportunistic carnivores that prey on a wide variety of species. In the Sierra National Forest, CA, they have not been studied since 1987 and their current interactions with their prey and other predators are unknown. Forest managers in this region are concerned with declines of fishers (Pekania pennanti) and studies have shown intraguild predation to be a leading cause of fisher mortality in this area. Managers are interested in learning more about mountain lion predation patterns with regard to prey preference, but also how lions traverse and use the landscape and how anthropogenic activities may be increasing lion predation risk on fishers. Using GPS radio-collar technology, we examined mountain lion kill rates and prey composition at 250 kill sites. We found mule deer (Odocoileus hemionus) to be their main source of prey (81%) with gray foxes (Urocyon cinereoargenteus) comprising 13.2% of prey composition. We did not detect any fisher predation during our 2-year study; however, during our study, the Kings River Fisher Project experienced extremely low juvenile fisher survival. To gain a better understanding of seasonal resource selection by mountain lions, we developed resource selection functions (RSF) while they were moving through the landscape and when killing prey. We developed RSF models for all data across the study area, as well as, for a subset of data encompassing an area where LiDAR (Light Detection and Ranging) data had been collected. Within the LiDAR study area, we digitized unmapped roads and skid trails using a Bare Earth data set. We found mountain lion ‘moving’ locations showed selection for close proximity to streams during summer months and selection for ruggedness and steeper slopes during both summer and winter. With 3 of the 4 RSF models at kill sites showing high risk of predation within close proximity to either digitized roads/skid trails or mapped roads, we recommend managers map all anthropogenically created linear landscape features and consider restoring these linear features to pre-treatment landscape conditions following timber harvest.

As part of a health survey of New Zealand sea lions (Phocarctos hookeri) on Enderby Island, Auckland Islands (50°30’S, 166°17’E), neonatal mortality was continuously monitored at the Sandy Bay Beach rookery, from 1998/1999 to 2004/2005. The primary causes of death were categorised as trauma (35%), bacterial (24%) and hookworm (13%) infections, starvation (13%) and stillbirth (4%). During the 2001/2002 and 2002/2003 breeding seasons, bacterial epidemics caused by Klebsiella pneumoniae increased mortality by three times the mean in non-epidemic years. Uncinaria spp. from New Zealand sea lion (NZSL) pups was described for the first time using morphometric criteria. It differed from the two species already described in pinnipeds, Uncinaria lucasi and Uncinaria hamiltoni, suggesting the existence of a different morphotype in NZSLs. A study on the epidemiology of hookworm infection showed that all pups up to at least three months of age harboured adult hookworms in their intestines and transmammary transmission was identified as the route of infection of NZSL pups. Uncinariosis as a primary cause of mortality was generally associated with anaemia, haemorrhagic enteritis and frank blood in the lumen. The relationship between hookworm burden and clinical disease could not be clearly established. The 2001/2002 and 2002/2003 bacterial epidemics at Sandy Bay Beach rookery were caused by a clonal strain of Klebsiella pneumoniae as verified by pulse-field gel electrophoresis and antimicrobial testing. Suppurative arthritis was the most common post-mortem diagnosis during the two epidemic seasons. Internal lesions were consistent with septicaemia, which explained the wide range of organs from which the pathogen was grown in pure culture. A serological test investigating the exposure of NZSLs to Klebsiella spp. showed that the large majority of pups up to two months of age did not have any anti-Klebsiella antibodies, even after the epidemics, but that almost all the adults were seropositive. In addition, passive immunoglobulin (Ig) transfer from lactating females to neonates was examined by measuring IgG levels in pups and was very low compared to terrestrial mammals although similar to other pinniped neonates.

Biological management of populations plays an indispensable role in all areas of population biology. In deciding between possible management options, one of the most important pieces of information required by population managers is the likely population status under possible management actions. Population dynamic models are the basic tool used in deriving this information. These models elucidate the complex processes underlying the population dynamics, and address the possible consequences/merits of management actions. These models are needed to guide the population towards desired/chosen management goals, and therefore allow managers to make informed decisions between alternative management actions. The reliability that can be placed on inferences drawn from a model about the fate of a population is undoubtedly dependent on how realistically the model represents the dynamic process of the population. The realistic representation of population characteristics in models has proved to be somewhat of a thorn in the side of population biologists. This thesis focuses in particular on ways to represent environmental stochasticity and density dependence in population models. Various approaches that are used in building environmental stochasticity into population models are reviewed. The most common approach represents the environmental variation by changes to demographic parameters that are assumed to follow a simple statistical distribution. For this purpose, a distribution is often selected on the basis of expert opinion, previous practice, and convenience. This thesis assesses the effect of this subjective choice of distribution on the model predictions, and develops some objective criteria for that selection based on ecological and statistical acceptability. The more commonly used distributions are compared as to their suitability, and some recommendations are made. Density dependence is usually represented in population models by specifying one or more of the vital rates as a function of population density. For a number of reasons, a population-specific function cannot usually be selected based on data. The thesis develops some ecologically-motivated criteria for identifying possible function(s) that could be used for a given population by matching functional properties to population characteristics when they are known. It also identifies a series of properties that should be present in a general function which could be suitable for modelling a population when relevant population characteristics are unknown. The suitability of functions that are commonly chosen for such purposes is assessed on this basis. I also evaluate the effect of the choice of a function on the resulting population trajectories. The case where the density dependence of one demographic rate is influenced by the density dependence of another is considered in some detail, as in some situations it can be modelled with little information in a relatively function-insensitive way. The findings of this research will help in embedding characteristics of animal populations into population dynamics models more realistically. Even though the findings are presented in the context of slow-growing long-lived animal populations, they are more generally applicable in all areas of biological management.

Parmi les contaminants introduits dans l'environnement, les éléments radioactifs artificiels apparaissent particulièrement importants à prendre en considération du fait de leur toxicité chimique et/ou de leur radiotoxicité. De nombreux radio éléments étant susceptibles de se retrouver associés aux sédiments, l'étude de la dynamique sédimentaire est un préalable nécessaire à l'étude de leur dispersion en mer. Cette thèse s'intéresse au devenir des sédiments dans le Golfe du Lion (NW de la Méditerranée) et en particulier à l'impact des apports du Rhône, principal vecteur de matière particulaire vers le milieu marin. Afin d'étudier les mécanismes du transport particulaire à différentes échelles spatiales et temporelles, cette thèse s'appuie sur la modélisation mathématique. Le modèle hydro-sédimentaire mis en place dans le Golfe du Lion, qui prend en compte l'effet conjoint des vagues et des courants, a été étayé par l'analyse de données hydro-sédimentaires récemment acquises. Des observations in situ obtenues au cours des expériences CARMA (hiver 2006/2007) et SCOPE (hiver 2007/2008) ont été utilisées pour mieux comprendre les processus physiques contrôlant le transfert des particules au niveau du prodelta du Rhône et valider le modèle mis en place. La période de la crue centennale du Rhône de décembre 2003 a également été simulée afin d'étudier l'impact de ce type d'évènement extrême sur le devenir des sédiments. Pour l'ensemble des périodes considérées, les observations et les simulations utilisées conjointement ont permis de mettre en évidence la capacité d'érosion et de transport importante induite au niveau du prodelta lors des tempêtes de sud-est

L'objectif de ce travail est l'étude de l'enregistrement sédimentaire de la marge du Golfe du Lion pendant son évolution post-rift. On met au point une méthodologie basée sur l'exploitation et de données disparates (Banque du Sous-Sol du BRGM, sismique réflexion industrielle, forages pétroliers profonds, affleurements de terrain), conduisant à des corrélations terre-mer haute-résolution et aboutissant à des interprétations de l'évolution post-rift de plusieurs segments de la marge. On met en évidence le rôle de la crise de salinité messinienne dans l'évolution de la marge et les modalités de la reconstruction de celle-ci, pendant le Plio-Quaternaire. Les évolutions variables selon les segments sont analysées, et mises en relation avec les contrôles locaux (héritages et /ou flux sédimentaires différents). Ces résultats sont appliqués à des problématiques de réservoirs aquifères littoraux.

Maintaining thermal balance is essential for all homeotherms but can be especially challenging for pinnipeds which must regulate over a variety of ambient temperatures and habitats as part of their life history. Young pinnipeds, with their immature physiology and inexperience, have the additional expense of needing to allocate energy for growth while still dealing with a thermally stressful aquatic environment. With the immense environmental and physiological pressures acting on juvenile age-classes, declines in prey resources would be particularly detrimental to survival. The goal of the present study was to examine the metabolic and thermoregulatory capabilities of juvenile Steller sea lions to better understand how changing prey resources indirectly impact juvenile age classes. Data collected from captive Steller sea lions suggest that changes in body mass and body composition influence the thermoregulatory capabilities of smaller sea lions in stationary and flowing water. Serial thermal images taken of sea lions after emergence from the water show vasoconstriction of the flippers compared to the body trunk to help minimize heat loss. Despite this ability to vasoconstrict, sea lions in poor body condition displayed a reduced tolerance for colder water temperatures, suggesting that decreases in prey availability which affect insulation may limit survival in younger sea lions. If reductions in prey availability (i.e., nutritional stress) were impacting western Alaskan populations, a reduction in energetic expenditures would be expected in these animals to cope. Measures of resting metabolism in juvenile free-ranging Steller sea lions across Alaska showed no differences between eastern and western capture locations, suggesting no evidence of metabolic depression in declining western stocks of sea lions. Finally, thermal costs predicted by a thermal balance model were compared to actual costs measured in the present study. Model output reliably predicted thermoregulatory costs for juvenile Steller sea lions under certain environmental conditions. Basic physiological measurements combined with the predictive power of modeling will allow for greater exploration of the environmental constraints on juvenile Steller sea lions and identify directions of future study.

The increasing importance of informal relationships derives from the steadily evolving and proceeding conditions in which we are involved in on a daily basis. These conditions range from the overall environment we are living in, over to our organizational working context and end up in our very own personal setting, namely our minds: in the end, we as human beings are the primary cause for the forming of such relationships, as they are established through our needs, concerns, wishes and fears. Furthermore, we are also highly influenced by our surrounding conditions, and so are the causes, types and effects of the so formed relationships. Our research offers an analytical as well as personal approach to bring the increasing importance of informal relationships to the minds of our readers. Especially leading figures in various organizational contexts are our target audience, as they have to cope with the also growing responsibilities and requirements that are accompanied by this process. Among scholars of this research field, there are many terms and expressions existing of such informal elements and happenings. Some speak of them as the ‘hidden assets’ of organizations, others entitle them as their ‘underlying powers’ and there also exist highly analytical notations, like for example ‘secondary adjustments’. However, all of them cannot entirely reproduce the thoughts and feelings we connect with our work. As we are now acting within the circle of these scholars, we take the liberty to add our own expression, which is best able to demonstrate our perception of such informal forces. We have given them the term ‘Lurking Lions’. They are powerful but also hard to encounter, as they are very well hidden behind the bushes of the formal organization and present without any noise. However, if our entitled lions realize some changes, threats or incentives in their environment, they are likely to reveal themselves and exert a drastic influence on the ones who caused them. By getting in contact with them, most people are likely to be overwhelmed as no one really knows about their thoughts, intentions and upcoming actions. Therefore, we tempt you to listen carefully, observe deeply and find out the nature of these ‘Lurking Lions’. By doing so, you can get a new powerful informal ally on your side.