Tesis sobre el tema "Sarcoptic mange"

La sarna sarcóptica es una enfermedad parasitaria causada por el ácaro Sarcoptes scabiei. Afecta a mamíferos de todo el mundo, incluyendo al ser humano. En la fauna salvaje se considera una enfermedad emergente, pudiendo causar graves consecuencias poblacionales. La cabra montés (Capra pyrenaica) es un ungulado de montaña endémico de la Península Ibérica. Desde finales de los años 80, las poblaciones de cabra montés del sur y del este peninsular se han visto afectadas por esta parasitosis, con mortalidades variables que han llegado a superar el 90%. La mayoría de los estudios sobre la sarna en la cabra montés se han centrado en la epidemiología y los efectos poblacionales, por lo que no se conoce totalmente la fisiopatología y la patogenia de esta enfermedad en esta especie. En los dos primeros estudios de esta tesis, se analizaron las proteínas de fase aguda (PFA) (Estudio I) y se validó una prueba para la detección de inmunoglobulinas G (IgG) frente S. scabiei (Estudio II) en cabras monteses en libertad, tanto sanas como afectadas por sarna sarcóptica. En el Estudio I, se observó el aumento de las concentraciones de la proteína amiloide sérica tipo A y de la alfa-1 glicoproteína ácida, aunque en menor medida, en función de la extensión de las lesiones causadas por la sarna sarcóptica. Por el contrario, la concentración de haptoglobina no varió entre las cabras monteses sanas y las infestadas. Debido a la falta de un método diagnóstico de laboratorio efectivo, en el Estudio II se evaluaron tres ensayos por inmunoabsorción ligada a enzimas (ELISAs) para detectar IgG frente a S. scabiei en cabra montés, validando uno de los tres ELISAs que mostró una elevada especificidad y sensibilidad, al emplear el sistema de avidina-biotina. Los Estudios III y IV se llevaron a cabo con cabras monteses que presentaban diferentes alelos del gen DRB1 del complejo mayor de histocompatibilidad (MHC) clase II, infestadas experimentalmente con S. scabiei. Aunque todas las cabras infestadas desarrollaron lesiones compatibles con sarna sarcóptica, la evolución clínica varió desde lesiones extensas que afectaron la mayor parte de la superficie corporal hasta lesiones leves y recuperación clínica de la enfermedad (Estudio III). Sin embargo, estas diferencias clínicas no parecieron estar relacionadas con diferencias en el MHC. En las cabras monteses que desarrollaron cuadros clínicos graves de sarna se observó anemia, posiblemente relacionada con la inflamación causada por el ácaro, así como neutrofilia y linfopenia, probablemente debidas a las infecciones secundarias facilitadas por la sarna sarcóptica. La concentración de IgG también aumentó en función de la gravedad de las lesiones. Finalmente, en el Estudio IV se estudió la respuesta genómica de las cabras monteses frente a la infestación experimental con S. scabiei. En las cabras monteses con cuadros clínicos graves se observó un aumento de la expresión génica de vías relacionadas con la inmunidad y la inflamación, reflejo de la respuesta inmune generalizada, exacerbada e ineficaz inducida por el ácaro y de la respuesta frente las infecciones secundarias. Asimismo, las cabras monteses que se recuperaron mostraron un aumento de la expresión de genes relacionados con la presentación de antígeno y de activación de linfocitos T en la piel. Como resumen, la sarna sarcóptica produce cambios tanto sistémicos como locales, causando un aumento de PFA y anticuerpos, así como alteraciones hematológicas y en la expresión génica local y sistémica. Aunque las causas de las diferencias encontradas en la evolución clínica no han podido ser completamente dilucidadas, la inmunidad celular local cutánea puede ser clave en el control de la infestación. La detección de IgG mediante ELISA puede ser útil como método diagnóstico efectivo de la sarna sarcóptica en cabra montés, mientras que las PFA son un indicador pronóstico.
Sarcoptic mange is a parasitic skin disease caused by the burrowing mite Sarcoptes scabiei. It affects mammals worldwide, including humans. Sarcoptic mange in wildlife is considered an emerging disease, and can cause severe population declines. Iberian ibex (Capra pyrenaica) is a medium-sized mountain ungulate endemic to the Iberian Peninsula. Since the end of the ‘80s, the Iberian Ibex populations of Southern and Eastern Spain have been affected by mange, suffering variables mortalities reported to reach up to 90%. Most of the studies on sarcoptic mange in Iberian ibex have focused on the epidemiology and the population consequences of the diseases, thus existing a lack of knowledge about the pathophysiology and pathogenesis of this disease in this species. The two first studies of this thesis analysed the acute phase proteins (APP) (Study I) and validated a test for the detection of immunoglobulins G (IgG) against S. scabiei (Study II) in free-ranging Iberian ibexes, both healthy and affected by sarcoptic mange. In the Study I, an increase of serum amyloid protein type A (SAA) and in lower magnitude of alpha-1 acid glicoprotein (AGP) concentrations was observed, in correlation with the extent of the skin lesions caused by sarcoptic mange. Conversely, haptoglobin (Hp) concentration was not different between the healthy and infested ibexes. Since there is not an effective laboratory diagnostic method, in the Study II three enzyme-linked immunosorbent assays were evaluated for IgG detection against S. scabiei in Iberian ibex, and one of the three showed high specificity and sensitivity by using the avidin-biotin system, which allowed it to be validated. The Studies III and IV were carried out on Iberian ibexes with different alleles of the DRB1 gen of the major histocompatibility complex (MHC) class II, experimentally infested with S. scabiei. Although all the infested ibexes developed lesions compatible with sarcoptic mange, the clinical evolution varied from extensive lesions affecting most of the body surface to mild lesions and clinical recovering of the disease (Study III). However, such clinical differences seemed unrelated to MHC differences. The severely affected ibexes showed anaemia, possibly related to the inflammation caused by the mite, as well as neutrophilia and lymphopenia, probably due to secondary infections favoured by sarcoptic mange. Immunoglobulin G concentration also increased in agreement with the severity of the lesions. Finally, the Study IV addressed the genomic response of Iberian ibexes to the experimental infestation with S. scabiei. The severely affected Iberian ibexes showed an increase in the gene expression of pathways related to immunity and inflammation, agreeing with the exacerbated and non-effective generalized immune response induced by the mite and the response to secondary infections. Moreover, the Iberian ibexes that recovered showed an increase in the local skin expression of genes related with antigen presentation and T-lymphocytes activation. To summarize, sarcoptic mange induces both systemic and local changes in the Iberian Ibex, causing an increase in APP and antibodies, as well as haematological and local and systemic gene expression disorders. Although the causes of the differences found in the clinical evolution have not been completely elucidated, local skin cellular immunity may be key in controlling the infestation. Immunoglobulin G detection by ELISA can be a useful and effective diagnostic tool for sarcoptic mange in Iberian Ibex, while APP are a prognostic indicator.

Sarcoptic mange affects the common wombat (Vombatus ursinus) throughout its range. Prevalence of the disease is generally low, with less than 5% of wombats in a population affected. However, epizootics occur sporadically. Sarcoptic mange is less prevalent in southern hairy-nosed wombats (Lasiorhinus latifrons) but may be widespread. Sarcoptic mange has not been reported in the sole remaining population of northern hairy-nosed wombats (Lasiorhinus krefftii) at Epping Forest, Queensland. Whilst mange epizootics are sporadic, they have the potential to threaten the survival of small, remnant populations of wombats.

Vertebrate species are managed for many reasons, including their role as economically important predators or as carriers of disease. Successful management depends on the ability to predict the outcome of management actions on a species’ population dynamics. However, uncertainty in the models used to make such predictions can arise from multiple sources, including sampling error in vital rates, intraspecific demographic variation and unknown interspecific interactions. The red fox Vulpes vulpes provides a useful model organism for exploring such uncertainty, because management of this important predator and disease host is often ineffective, despite substantial sampling effort. By explicitly accounting for sampling error in survival and fecundity, confidence intervals for population growth rates were derived from published point estimates of red fox demographic data. Uncertainty in population growth rates was found to be high, requiring a quadrupling of sampling effort to halve the confidence intervals. Given the often poor justification for the choice of distribution used to model litter size, the influence of probability distributions on population model outcomes was tested. In this first comprehensive evaluation, estimates of quasi-extinction and disease control probabilities for three Canid species were found to be robust to litter size distribution choice. Demographic analyses of the red fox revealed a medium to fast life history speed and significant survival and fecundity contributions from juveniles to population growth. Intraspecific variation was detected within these spectra of demographic metrics: the first such demonstration for carnivores. Simulated data substitution between fox populations revealed that geographic proximity and similar levels of anthropogenic disturbance did not infer demographic similarity. Considering the sampling effort expended on the red fox, the species appears well-studied; yet, substantial limitations in data collection were identified. Compartment modelling of a sarcoptic mange outbreak in an urban fox population in Bristol, UK, revealed that disease transmission was frequency-dependent, consistent with contact rates being determined by social interactions rather than by population density. Individual-based modelling suggested that indirect transmission, genetic resistance and long-distance recolonisation were required to replicate the observed rapid spread of mange and subsequent population recovery. Thus, this first attempt to model mange dynamics in this canid provided novel insight into previously uncertain epidemiological and behavioural processes in the transmission of sarcoptic mange in the red fox.

Red foxes (Vulpes vulpes) have been identified as a key predator of the threatened piping plover (Charadrius melodus) along the U.S. Atlantic coast. However, little is known about coastal red fox ecology, making it difficult to create effective red fox management strategies in these settings. Here, we quantify aspects of red fox population, spatial, and dietary ecology and interactions with threatened piping plovers on Fire Island, New York. We conducted remote camera surveys, scat and sign surveys, den monitoring, and GPS tracking of red foxes on the island in 2015–2018. We used these data to estimate red fox occupancy, reproduction, survival, and population density. We used GPS data to investigate red fox space use, habitat selection, and responses to piping plover nest exclosure setup, pre-hatch pipping, and hatching. We used fecal dietary analyses and data from den prey item surveys to quantify the frequency of piping plover predation and to identify major prey items of red foxes on the island. Red fox occupancy remained high even after substantial decreases in abundance, population density, annual reproduction, and seasonal survival following 2 sarcoptic mange outbreaks. Within their home ranges, red foxes selected areas that were closer to vegetation during the daytime and twilight hours, but farther from vegetation at night. We did not find clear evidence that red foxes in our study area keyed in on piping plover nest exclosure setup, pipping, or hatching at the spatial scales considered in our comparisons, although fox penetration of and digging at exclosures was an issue in 2015 at Smith Point County Park. Items from Orders Rodentia (rodents, 43% of scats), Coleoptera (beetles, 38%), and Decapoda (crabs and other crustaceans, 29%) were most frequently found in 293 red fox scats examined. Skates (Family Rajidae, 89% of dens with food items) and Atlantic surf clams (Spisula solidissima, 67%) were found most frequently outside of dens. We did not find any identifiable piping plover remains in red fox scats or outside of dens. Our results suggest that direct interactions between red foxes and piping plovers during our study period and in our study area were less frequent than expected, but concurrent work by collaborators documented that the trap success of red foxes was negatively related to piping plover reproductive output during our study period. Lethal removal of red foxes is unlikely to eliminate them from shorebird nesting areas unless complete eradication of foxes from the island can be achieved. We recommend strategic vegetation management in and around piping plover nesting areas to reduce daytime resting areas and hunting cover for red foxes, and continued use of nest exclosures. We also recommend further investigation into indirect impacts of red foxes on piping plover populations, and into the possibility that anthropogenic food resources could be subsidizing the island's red fox population.
Doctor of Philosophy
Red foxes have been identified as a key predator of the piping plover, a small migratory shorebird that breeds along the U.S. Atlantic coast and is considered 'threatened' (at risk of becoming endangered and eventually disappearing) within the United States. The lack of information about red fox ecology in coastal settings has been a challenge for wildlife biologists tasked with reducing predation on piping plovers. We investigated red fox ecology, behavior, and interactions with piping plovers on Fire Island, New York. We used trail cameras, collected scat (feces), monitored dens, and tracked red foxes on the island with global positioning system (GPS) collars in 2015–2018. We used these data to estimate red fox distribution, litter sizes, survival rates, and population sizes. We used GPS data to estimate red fox territory sizes, describe habitat selection, and investigate responses to piping plover nest exclosure setup, pipping (a period before hatching during which chicks vocalize inside the eggs), and hatching. We dissected red fox scats and recorded prey items found outside of dens to determine what red foxes on the island were eating. The proportion of each study area used by red foxes remained high even after substantial decreases in abundance, population density, annual reproduction, and seasonal survival following 2 parasitic disease (sarcoptic mange) outbreaks. Within their territories, red foxes selected areas that were closer to vegetation during the daytime and twilight hours but farther from vegetation at night. We did not find clear evidence that red foxes in our study area keyed in on piping plover nest exclosure setup, pipping, or hatching, although fox penetration of and digging at exclosures was an issue in some years at a site not included in those comparisons. Rodents, beetles, and crustacean remains were found most frequently in red fox scats. Skates and surf clams were found most frequently outside of dens. We did not find any identifiable piping plover remains in red fox scats or outside of dens. Our results suggest that that direct interactions between red foxes and piping plovers may be less frequent than previously believed, but concurrent work by collaborators documented that the trap success of red foxes was negatively related to piping plover reproductive output during our study period. Lethal removal of red foxes is unlikely to eliminate red foxes from shorebird nesting areas unless all foxes on the island are removed. We recommend strategic vegetation removal in and around piping plover nesting areas to reduce daytime resting spots and hunting cover for red foxes, and continued use of nest exclosures. We also recommend further investigation into indirect impacts of red foxes on piping plover populations, and into the possibility that anthropogenic food resources could be subsidizing the island's red fox population.

Der zu den bedeutendsten Ektoparasiten des Schweines gehörende Erreger der Schweineräude, Sarcoptes scabiei var. suis, ist weltweit verbreitet und von wirtschaftlichen Interesse für Schweinezucht- und Mastbetriebe. Ziel dieser seroepidemiologischen Studie war die Gewinnung neuer Erkenntnisse über die Bestandsdynamik klinischer Räudeerscheinungen und dem Titerverlauf von IgG-Antikörpern gegen Sarcoptes scabiei var. suis im Serum von Sauen in Abhängigkeit vom Reproduktionszyklus (Trächtigkeit, Laktation, Besamung) und von Saugferkeln während der Säugeperiode sowie Aufzucht. Schlussfolgernd aufgrund der Ergebnisse dieser Studie eignen sich für die Kontrolle und Überwachung sowie Diagnostik der Sarcoptes-Räude von Beständen serologische Untersuchungen von Ferkeln bis zur zweiten Lebenswoche von räudeverdächtigen Sauen, „Jungsauen erster und zweiter Wurf“ sowie Sauen während der Trächtigkeit (vor allem letztes Drittel) und Deckeber. Eine Vorselektion auf räudeverdächtige Hautveränderungen sowie gesteigerte Kratzaktivitäten erhöht die Wahrscheinlichkeit serologisch positive Tiere zu identifizieren.

Sarcoptes scabiei est un acarien ectoparasite obligatoire. Sa présence dans la couche cornée de l’épiderme est à l’origine d’une gale dite sarcoptique. Cette ectoparasitose a été décrite chez 104 espèces de mammifères représentant 27 familles distinctes. Les traitements actuels de la gale sarcoptique ne sont pas toujours satisfaisants et il n’existe pas de produits qui permettent d’éliminer S. scabiei dans l’environnement. Par ailleurs, la diversité génétique de S. scabiei n’est pas clairement définie et l’unicité de l’espèce fait toujours l’objet de controverses.L’objectif de cette thèse a été d’évaluer l’efficacité d’acaricides vis-à-vis de S. scabiei en utilisant un modèle animal ou par le biais de tests in vitro. La diversité génétique d’isolats d’origine animale a également été étudiée. La première partie du travail de thèse a concerné un essai thérapeutique L’efficacité d’une administration orale unique d’afoxolaner, une molécule du groupe des isoaxazolines, a été évaluée sur des porcs expérimentalement infestés. Le critère principal d’évaluation a été la réduction du nombre de sarcoptes mis en évidence dans les raclages cutanés. Huit jours après le traitement, aucun sarcopte n’a été détecté sur les 4 porcs ayant reçu l’afoxolaner alors que des sarcoptes étaient toujours présents sur les 3 porcs ayant reçu de l’ivermectine. Tous les porcs traités étaient guéris à la fin de l’essai (J35) alors que les animaux non traités sont demeurés infestés. Les autres critères d’évaluation étaient l’évolution du score clinique et de prurit. Les lésions cutanées ont rapidement régressé dans le groupe traité par l’afoxolaner alors qu’elles étaient encore présentes à J14 dans le groupe traité avec l’ivermectine. La deuxième partie du travail de thèse a porté sur l’évaluation in vitro de différentes molécules ou produits acaricides. Plusieurs concentrations d’une solution d’ivermectin ou de moxidectine ainsi 11 huiles essentielles ont été testées. Après 24h de contact avec l’ivermectine et la moxidectine, la dose létale 50% étaient de 150,2±31,4 µg/mL et 608,3±88,0 µg/mL, respectivement. Une concentration inférieure à 1 ng/mL (pour l’ivermectine) ou à 10 ng/mL (pour la moxidectine) n’a aucune activité acaricide. Pour les huiles essentielles, des tests par fumigation et par immersion ont été réalisés. Parmi Lavandula augustifolia, Melaleuca altenifolia, Pelargonium asperum, Eucalyptus radiate, Leptospermum scoparium, Cryptomeria japonica, Citrus aurantium ssp amara et 3 l’huile essentielle identifiée (BOB4, BOB5, BOB9) testés par immersion, l’huile essentielle identifiée BOB4 s’est révélée la plus efficace (une solution à 1% tue tous les acariens en 20 min). Parmi les 10 huiles essentielles énumérées avant, plus Juniperus oxycedrus testés par immersion, l’huile essentielle de Melaleuca altenifolia s’est révélée la plus efficace (tous les acariens sont morts en 4 min). Pour le contrôle de S. scabiei dans l’environnement, différents biocides ou répulsifs ont été examinés. La durée moyenne de survie a été calculée pour les produits comportant de la perméthrine, de l’esdépallethrine et de la bioresmethrine, de la bifenthrine, de la cyperméthrine et de l’imiprothrine, de la cyfluthrine, de la tétramethrine et de la sumithrine, du DEET, de l’icaridine et le produit IR3535. La deuxième partie du travail de thèse a porté sur la diversité génétique d’isolats de S. scabiei provenant d’animaux. Une partie du gène cox1 a été amplifiée. L’analyse des séquences ainsi obtenues semble montrer que les sarcoptes circulant chez le Chien sont issus de population de sarcoptes d’origine humaine
Sarcoptes scabiei is an ectoparasite responsible for the emerging/re-emerging disease called scabies in humans or mange in animals. It was reported in 104 species across 27 families of domestic and wild animals. Current treatments for scabies/mange are limited and there are no efficient products for the environment control of S. scabiei. Moreover, the taxonomic status of S. scabiei is still under controversy and the question remains that whether it represents a single species or several taxa.The objectives of the thesis were to assess the susceptibility to acaricides and analyse the genetic diversity of S. scabiei from animals. In the first part of the thesis, an animal model was used to evaluate the efficacy of afoxolaner, a new acaricide from the isoaxazoline family. The primary outcome of efficacy was based on the reduction in the number of live mites counted in skin scrapings following treatment. At day 8, four afoxolaner-treated pigs (out of four) were mite-free, while mites were still found in three (out of three) ivermectin-treated pigs. All treated pigs were cured at the end of the study (day 35) and all pigs in the control group remained infected. Secondary outcomes included measures on the reduction of skin lesions and pruritus. The clinical lesions of scabies infection were allowed to disappear completely for all the pigs in the afoxolaner group but not in the ivermectin group at 14 days after the treatment. An increase of the pruritus was observed right after treatment, followed by a decrease of the pruritus score in both treated groups. The second part of the thesis was to evaluate the scabicidal effect of molecules or products using an in vitro test. A gradient of concentrations of ivermectin and moxidectin as well as 11 essential oils have been evaluated in vitro against S. scabiei. After 24h of exposure to ivermectin and moxidectin, the median lethal concentrations were 150.2±31.4 µg/mL and 608.3±88.0 µg/mL, respectively. Doses of ivermectin under 1 ng/mL and moxidectin under 10 ng/mL showed no scabicidal effect. Fumigation and contact bioassays were used for the assessment of essential oils efficacy. Among Lavandula augustifolia, Melaleuca altenifolia, Pelargonium asperum, Eucalyptus radiate, Leptospermum scoparium, Cryptomeria japonica, Citrus aurantium ssp amara and 3 other unknown oils (BOB4, BOB5, BOB9) tested with the contact bioassay, the essential oil identified as BOB4 demonstrated the best scabicidal effect (1% solution killed all the mites in 20 min). Among the 10 essential oils listed before plus Juniperus oxycedrus with the fumigation bioassay, the oil Melaleuca altenifolia demonstrated the best scabicidal effect (all the mites died in only 4 min). For environmental control of S. scabiei, the efficacy of biocides or repellents was assessed. The median survival time was calculated for permethrin (4% and 0.6%), esdepallethrin and bioresmethrin, bifenthrin, cypermethrin and imiprothrin, cyfluthrin, tetramethrin and sumithrin, DEET (25% and 50%), icaridin and IR3535. The third part of the thesis included the study of the genetic diversity of populations of S. scabiei from animals. A part of cox1 was used for phylogenetic analyses. The results showed that Sarcoptes mites from dogs seem to derive from humans

碩士
國立屏東科技大學
野生動物保育研究所
100
Infection diseases can regulate or impact the host population dynamics, espencially for the newly introduced pathogen. Sarcoptic mange (Sarcoptes scabiei) with various variations was distributed worldwide and has been found species-specific infectation in human, domestic animals and wildlife. High mortalities have been observed in different wildlife populations worldwide. S. scabiei infectation in Formosan serow (Capricornis swinhoei) was first found in 2007. However, the source of scabies mites and their impacts on serow populations are unclear. The risk of mutual infection between Formosan serow and domestic animals are also unknown. This study revealed the phylogenetic relationship among scabies mites infecting wild Formosan serow and domestic animals in Taiwan. A 1023-bp fragment of the cytochrome oxidase gene subunit I (COI) on mitochondrion and 14 microsatellite markers were used for phylogenetic analysis. Results show that S. scabiei in serow, goat and rabbit populations may have the same origin. S. scabiei has isolated in serow population for at least 97,000 years. There is no recent transmission of S. scabiei among domestic animals and wild Formosan serow.

An unintended consequence of the global movement of humans and their domestic animals has, and continues to be, the introduction of pathogens to naïve host species. Such pathogen invasion events have consequences for wildlife ranging from benign to catastrophic. Yet, the specific impacts to affected species – from individuals to populations – and the capacity to mitigate these are often poorly understood. This is perhaps best illustrated in mammals by the parasitic mite, Sarcoptes scabiei (causative agent of sarcoptic mange): among the most successful of known pathogens to benefit from anthropogenic globalisation. The mite now occurs on all continents (except Antarctica) and has been documented infecting >100 mammal species, yet the impacts of this parasite remain enigmatic for most wildlife species it infects. In Australia, evidence indicates S. scabiei was introduced by European settlers. Over the last 200 years, S. scabiei has been documented in several native and non-native Australian mammals, with most striking impacts observed in the bare-nosed (common) wombat, Vombatus ursinus. Though sarcoptic mange causes conservation, ethical, and welfare concerns to V. ursinus, considerable knowledge gaps have persisted about the effects of the parasite, including the impacts of infection on individuals and at population scales, as well as the capacity to mitigate infection. Furthermore, there is a dearth of fundamental knowledge about the V. ursinus host, despite being a perceived “common” species. The aims of this thesis were therefore four-fold: (i) to identify behavioural and physiological impacts of S. scabiei presence at the individual level, (ii) to quantify the population-scale impact of a sarcoptic mange outbreak in a bare-nosed wombat population, (iii) to evaluate the efficacy of the current suggested treatment protocol administered at a population-scale, and (iv) to understand the genetic structure of V. ursinus across its entire range (encompassing three subspecies). To understand the impacts of sarcoptic mange at the individual level, I focused on physiological and behavioural changes observed in mange-infected bare-nosed wombats. Specifically, I investigated the effect of sarcoptic mange infection on heat loss, field metabolic rate, resting and foraging behaviour, and fatty acid composition (Chapter 2). I used methods in thermal imagery, doubly labelled water, activity loggers, and fat composition profiles to reveal that as mange severity increased in wombats, (i) heat lost to the environment increased, (ii) field metabolic rates increased, (iii) total time spent foraging decreased while total time spent inactive increased, and (iv) fatty acid composition changed in adipose tissue. I concluded that the compounding effects of physiological and behavioural changes left infected wombats unable to meet the energetic demands of sarcoptic mange disease. The pattern of disease spread and impact of an outbreak on bare-nosed wombat abundance was assessed at Narawntapu National Park (north-central Tasmania) during a mange epizootic. I used seven years of population data and four years of disease severity data in combination with piece-wise linear regressions and geographic heat maps to understand the consequence of mange outbreak in a semi-isolated wombat population. I found that disease spread through Narawntapu National Park spatiotemporally, in a wave-like pattern from east to west, and caused a >94% decline in wombat abundance from 2010-2016 (Chapter 3). Furthermore, I suggested that sarcoptic mange outbreaks can result in localised extirpation in semi-isolated populations. During the outbreak event at Narawntapu National Park, I attempted a population scale treatment regime based on the current suggested treatment protocols (Chapter 4). I administered treatment to >200 burrows for 12 consecutive weeks and performed disease severity surveys for 18 months to quantify the efficacy of the treatment regime. I found that current treatment methods provided temporary protection, but were not sufficient to eradicate mange from the park, and reinfection occurred shortly after treatment ceased. Using a novel, purpose-built, state-based model fitted to empirical data from the treatment trial, I explored practical changes to current treatment methods that may influence treatment outcomes. I found that treatment application success was low using current techniques, and that a longer lasting treatment may facilitate capacity for future population scale disease control. Finally, I sought to develop a baseline understanding of V. ursinus genetic structure across its range, as well as address the currently accepted subspecific claims (mainland V. u. hirsutus, Flinders Island V. u. ursinus, Tasmania V. u. tasmaniensis). Using genome-wide single nucleotide polymorphisms, I identified (i) three genetically distinct groups, consistent with current subspecies classifications, (ii) a second population of the Vulnerable V. u. ursinus on Maria Island (an offshore island of Tasmania), and (iii) isolation by distance across the Tasmanian range (Chapter 5). I concluded that the three subspecies may better be managed as separate units. The work presented in this thesis has contributed to a greater understanding of: (i) the impacts of sarcoptic mange, at the individual and population level, in bare-nosed wombats, (ii) the efficacy of current treatment methodologies and potential improvements to future management regimes, and (iii) the baseline genetic structure of V. ursinus, identifying three genetically distinct subspecies that may warrant separate management action. The contributions I have made to V. ursinus and S. scabiei research will help to inform future disease management efforts for this species and provides insight to management of evolutionary significant units within the V. ursinus range. Moreover, this thesis contributes to the broader understanding of an invasive, globally significant, and environmentally transmitted pathogen, with conservation implications for other impacted species and similarly transmitted invasive pathogens impacting wildlife.

Populations of bare-nosed wombats (Vombatus ursinus) are under threat across Australia and one of the major causes of their mortality is sarcoptic mange. Reasons for this high susceptibility are being investigated. On conducting a thorough search through literature, it was observed that although the current treatment practice can successfully restrict sarcoptic mange prevalence in small captive bare-nosed wombat populations, the same is not true for large free-ranging populations. Environmental factors such as drought, habitat degradation and anthropogenic interference can act as potential stress factors to exacerbate the effects of sarcoptic mange. During stress, the hypothalamic pituitary adrenal (HPA) axis is stimulated to release stress hormones (glucocorticoids - GC) that can influence immune function. Past research has suggested that chronic stress is associated with immunosuppression which can play a role in disease incidence. Additionally, a high prevalence of secondary endoparasitic infestations have been reported to be associated with sarcoptic mange incidence. To better comprehend the parameters that influence sarcoptic mange incidence in bare-nosed wombats, this study employed non-invasive procedures that enable evaluation of endoparasitic and stress load in these marsupials. Non-invasive faecal sampling is ideal for large nocturnal marsupials like bare-nosed wombats. Validation of species-specific enzyme immunoassay (EIA) is necessary. This thesis aimed to optimise techniques suitable for quantifying faecal cortisol metabolites (FCM) (end products of HPA axis activation) in the voided excreta of bare-nosed wombats. One in-house and one commercial EIA was successfully validated to monitor the adrenocortical activity in these marsupials. Faecal samples collected from free-ranging wombats are usually <12 h old. Faecal hormone metabolites are vulnerable to bacterial activity and hence the knowledge of the decay rate of these metabolites in voided faeces is essential. This study determined the decay rate and baseline level of FCM in captive bare-nosed wombat faecal samples. Faecal samples collected from free-ranging wombats located in five different locations in N.S.W, Australia were analysed to evaluate their endoparasite and stress load simultaneously. My research brought new insights into the current parasitological and stress profiles of bare-nosed wombats as well as the current sarcoptic mange prevalence in these marsupials at the five study sites. This study demonstrated that an increase in FCM level among bare-nosed wombat populations could increase the probability of being infected with sarcoptic mange. The outcome of this study agrees with the corticosteroid-fitness hypothesis, which envisages that an increase in the levels of GC hormones can result in reduced fitness of organisms and hence can result in lower fecundity and higher risk of developing an infection. This can lower chances of future population survival. To the best of my knowledge, this is the first study that incorporates endoparasitic load, chronic stress and sarcoptic mange prevalence in bare-nosed wombat populations in N.S.W, Australia in both empirical and experimental approaches.

Size-selective harvesting (e.g. trophy hunting) involves removing specific individuals that exhibit desirable phenotypes. The ecological and evolutionary consequences of selective harvesting are controversial because it remains unclear how environmental conditions dilute or strengthen the effects of this activity. In Spain, the trophy hunting of male Iberian ibexes (Capra pyrenaica Schinz, 1838), associated with the ongoing environmental changes of the Mediterranean basin, may have undesirable consequences on the phenotypic traits and population dynamics of this species. By analysing a comprehensive hunting inventory of individual body condition, and correspondent individual metrics, gathered from wild Iberian ibex populations, this thesis is aimed at investigating the direct and indirect pathways by which hunting strategy, environmental conditions, density-dependence factors and diseases (e.g. sarcoptic mange) influences the phenotypic traits of Iberian ibex. The first study (chapter 2), carried out in the Els Ports de Tortosa-Beseit National Hunting Reserve, northeast Spain, showed that ibexes diet includes a wide range of plant species, that both diet quality and composition follows a seasonal pattern driven by landscape heterogeneity and that the diversity of ibex diet, together with the heterogeneity of Mediterranean ecosystems, hamper the use of remotely sensed products (e.g. Normalized Difference Vegetation Index) to predict dietary features, i.e. systematic faecal samples are necessary to update the nutritional condition of ibex individuals. Then, two long-term observational studies highlighted the importance of habitat characteristics on the horn growth patterns of male ibexes. The first study (chapter 3) showed that habitat fostered significant horn growth differences among males and confirmed that compensatory horn growth does not occurs in male ibexes. The second study (chapter 4) demonstrated that pine forest encroachment accounted for the decrease of annual segments length over the last two decades and suggested that the selective removal of slow-growing, small-horned males could be important to mitigate the undesirable consequences of trophy hunting. The last study (chapter 5), carried out in the Sierra Nevada National Park, south Spain, indicated that the bottom-up regulation of body condition is disrupted by highly infectious parasitic diseases, such as the sarcoptic mange. Apart from representing an important scientific contribution towards a better understanding of Iberian ibex ecology, the results of this thesis have great implications for the management of Mediterranean ungulates and open a direct venue for scientific cooperation and collaborative planning. The synergies between hunters, game managers and researchers are of utmost importance to achieve the long-term sustainability of Iberian ibex populations.
A caça seletiva (e.g. caça troféu) consiste na remoção de indivíduos com determinadas características fenotípicas de uma população selvagem. Apesar de ser uma prática comum, as suas consequências ecológicas e evolutivas são controversas, pois não é claro se as condições ambientais diluem ou intensificam os efeitos desta atividade. Em Espanha, a exploração cinegética do macho-montês (Capra pyrenaica Schinz, 1838), através da caça troféu, juntamente com as alterações ambientais registadas na bacia Mediterrânica, podem traduzir-se num efeito indesejado nas características fenotípicas e dinâmica populacional da espécie. Mediante a análise de um extenso repositório de informação individual sobre métricas de crescimento e condição corporal, esta tese tem como principal objetivo determinar os efeitos diretos e indiretos da estratégia de caça, das condições ambientais, da densidade populacional e da sarna sarcótica nas características fenotípicas da cabra-montês. O primeiro estudo (capítulo 2), realizado na Reserva Nacional de Caça de Els Ports de Tortosa-Beseit, nordeste de Espanha, confirmou o quão sazonal e diversa é a dieta da cabra-montês em ambientes Mediterrânicos e demonstrou que a heterogeneidade dos ecossistemas Mediterrânicos torna necessária a realização de amostragens sistemáticas para a atualização dos dados relativos à dieta da espécie, um aspeto crucial para o desenvolvimento de diversos caracteres sexuais secundários. Posteriormente, dois estudos observacionais revelaram a importância do habitat nos padrões de crescimento dos segmentos córneos do macho montês. O primeiro (capítulo 3) demonstrou que a heterogeneidade individual da longitude dos anéis de crescimento é potenciada por diferenças no habitat e que os machos não são capazes de recuperar do crescimento deficitário dos anéis após um eventual período de défices nutricionais. O segundo (capítulo 4) evidenciou que o aumento da área de pinhal, e consequente diminuição da área de pastagens naturais, é um fator decisivo para o decréscimo contínuo da longitude dos anéis de crescimento ao longo das últimas duas décadas. Este último, sugere também que a extração seletiva de animais com reduzidas taxas de crescimento pode contribuir para a mitigação dos efeitos da caça troféu. O último estudo (capítulo 5), realizado no Parque Nacional de Sierra Nevada, sul de Espanha, revelou que a regulação da condição corporal exercida por aspetos ambientais e populacionais é quebrada por infeções parasitárias contagiosas, como a sarna sarcóptica. Além da sua importância ecológica, os resultados aqui reportados traduzem-se num conjunto de medidas de ampla aplicabilidade para a gestão das populações de cabra-montês. A presente tese reforça a importância das sinergias entre caçadores, gestores de caça e investigadores tendo em vista a sustentabilidade da atividade cinegética e das populações ibéricas de cabra-montês.
Programa Doutoral em Biologia

Der zu den bedeutendsten Ektoparasiten des Schweines gehörende Erreger der Schweineräude, Sarcoptes scabiei var. suis, ist weltweit verbreitet und von wirtschaftlichen Interesse für Schweinezucht- und Mastbetriebe. Ziel dieser seroepidemiologischen Studie war die Gewinnung neuer Erkenntnisse über die Bestandsdynamik klinischer Räudeerscheinungen und dem Titerverlauf von IgG-Antikörpern gegen Sarcoptes scabiei var. suis im Serum von Sauen in Abhängigkeit vom Reproduktionszyklus (Trächtigkeit, Laktation, Besamung) und von Saugferkeln während der Säugeperiode sowie Aufzucht. Schlussfolgernd aufgrund der Ergebnisse dieser Studie eignen sich für die Kontrolle und Überwachung sowie Diagnostik der Sarcoptes-Räude von Beständen serologische Untersuchungen von Ferkeln bis zur zweiten Lebenswoche von räudeverdächtigen Sauen, „Jungsauen erster und zweiter Wurf“ sowie Sauen während der Trächtigkeit (vor allem letztes Drittel) und Deckeber. Eine Vorselektion auf räudeverdächtige Hautveränderungen sowie gesteigerte Kratzaktivitäten erhöht die Wahrscheinlichkeit serologisch positive Tiere zu identifizieren.

碩士
國立屏東科技大學
野生動物保育研究所
102
Between November 2010 and March 2011, ten (2 females and 8 males) Taiwanese serows (Capricornis swinhoei) were captured and radio-collared within an area of 2km2 around the Nantzuhsienchi Conservation Station. Two mange species, Sarcoptes scabiei and Chorioptes texanus, were found on these serows with a 70% and 80% infestation rate respectively. Among others, A10 individual had been assessed in the recovery stage of the sarcoptes mange infestation, therefore two sets of analyses were undertaken for this study, one with A10 classified as an infested individual, one with A10 classified as a non-infested case. The mortality of sarcoptes mange infestation was between 14.3% and 57.1%, and no non-infested or Chorioptes texanus infested only serow died during the study. The radio-tracking results indicated that when A10 was classified as an infected individual, average home range for sarcoptes mange non-infested serows were 39.7ha (95% Minimum convex polygon, MCP) and 61.2ha (95%Fixed Kernel, FK) respectively, while the average home range for infested serows were 31.9ha and 53.4ha. When A10 was classified as mange infested individual, average home range for non-infested serows were 35.9ha and 56.2ha, while that of infested serows were 36.7ha and 59.1ha. Individual variation in home range size was much higher among infested serows. There was no significant difference in home range size between infested and non-infested serows, however, when A10 was classified as a non-infested case, the core area (50%) of non-infested serow was significant larger than the infested ones. The daily activity levels of non-infested serows were also significantly higher. Results showed that among the five habitat types of broadleaf forest, coniferous forest, conifer-broadleaved mix forest, grassland and rocky slope caused by land sliding, serows prefer broadleaf forests and rocky slope; however, sarcoptes mange infested serows prefer conifer-broadleaved mix forest and rocky slope, which might suggest infested individuals prefer habitat with more direct sunlight in the daytime.