<p> The bushtit (Psaltriparus minimus) of Southeastern Arizona is a cooperative breeder, in which 35% of nests have more than two birds attending. Helpers. join nests at all stages of the breeding season, and potentially make genetic contributions to the nest. Behavioural observations suggest that the fluid social system of the bushtit may provide opportunities for extra-pair fertilizations (EPFs) and intra-specific brood parasitism (ISBP). DNA fingerprinting was applied to assess parentage in the 1988 and 1992 breeding seasons. Using three minisatellite probes (Jeffreys 33.15, 33.6 and PER), fingerprints were generated from nine complete families (nestlings and adults) from 1992 and twelve families of nestlings, in this study, from 1988. Parentage analysis of the 1992 families indicated strict genetic monogamy, despite the fact that two of the breeding groups were socially polyandrous. A case of serial monogamy in a double-brooded nest provided evidence of a male helper achieving reproductive success after aiding in the rearing of non-kin in the first brood. This result suggests the potential reproductive benefits of helping behaviour in a double-brooding species. Genetic relatedness, within groups of nestlings from the same brood, was analyzed in the 1988 samples. In using the 1992 data as a calibration, the 1988 broods were found to contain no unrelated dyads resulting from ISBP. Discrimination between full and half­ sibling relationships was less clear. The analysis of relatedness serves as a useful comparison to other studies that have used a multiple probe approach to assess relatedness. </p> / Thesis / Master of Science (MSc)

This thesis is involved with changes that have occurred to small mammal populations following a major disturbance in the Anglesea region as a result of the 1983 Ash Wednesday fires. Fire, with its effects on spatial and temporal heterogeneity, was found to be an important factor in the maintenance of vegetation and small mammal community structure and diversity in the region. Successional changes in vegetation and small mammal communities were described by multivariate analyses, using data collected annually from 22 study sites. The use of factor analysis techniques, in reducing the annual capture data content, enabled long-term changes in the structure of mammal communities to be interpreted. The small mammal communities in the coastal heath and forest vegetation in the Anglesea region show evidence of a general resilience, (the degree and speed of recovery), to disturbance. Two phases of successional response to fire by mammal species have been proposed; a ‘re-establishment’ phase which occurs in the initial 5-6 years post-fire and is accompanied by rapid increase in species’ abundance, and a subsequent ‘maintenance’ phase accompanied by relatively minor changes in abundance. Habitat Suitability Indices were produced relating to these phases. Vertical density measures of understorey shrubs and herb layers showed significant relationships with small mammal species abundance at the study sites. Long term studies following major disturbances are needed to distinguish between short term recovery of plant and animal species and long term changes in these species. Studies extending over a number of years enable a better directional view of changes in small mammal communities than can be determined from . observations made over a short period. As a part of the investigation into temporal change, it was proposed to undertake trial reintroductions of the Swamp antechinus, Ant echinus minimus, a marsupial dasyurid species which was trapped in the area prior to the 1983 fire, but rarely subsequently. Other more commonly observed native small mammal species (e.g. Rattus fuscipes,R. lutreolus, Antechinus stuartii, Sminthopsis leucopus) had re-invaded the proposed reintroduction site after this fire. Failure of A. minimus to re-establish may have been due to spatial separation of the pre-fire populations coupled with the extensive area burnt in 1983, A source population of the species was located about 100km to the west and habitat utilization and interspecific and niche relationships between the species making the small mammal community explored. Discriminant analysis revealed some spatial separation of species within a habitat based on structural vegetation factors rather than floristic factors. Temporal separation of species was observed, asA. minimus were more active than Rattus species during daylight periods. There was evidence of micro-habitat selection by species, and structural vegetation factors were most commonly identified in statistical analyses as contributing towards selection by small mammal species. Following a theoretical modelling study three reintroduction trials were carried out near Anglesea during 1992-94. Individuals were subsequently radio tracked, and habitat relationships between the species in the small mammal community investigated. Although successful breeding of A, minimus occurred during the latter two trials, the subsequent fate of offspring was not determined. Invasive techniques required to adequately monitor young animals were considered potentially too damaging. Telemetry studies indicated a preference of A. minimus for short, wet heath vegetation. Structural vegetation factors were identified as being significant in discriminating between capture locations of species. Small scale and inexpensive trial reintroductions have yielded valuable additional data on this species and may be viewed as a useful tool in the conservation of other small native mammals.

The purpose of this study is to determine if element decimation of a 3-D anatomical model affects the results of Finite Element Analysis (FEA). FEA has been increasingly applied to the biological and medical sciences. In order for an anatomical model to successfully run in FEA, the 3-D model’s complex geometry must be simplified, resulting in a loss of anatomical detail. The process of decimation reduces the number of elements within the structure and creates a simpler approximation of the model. Using the National Library of Medicine’s Visible Human Male dataset, a virtual 3-D representation of several structures of the hip were produced. The initial highest resolution model was processed through several levels of decimation. Each of these representative anatomical models were run in COMSOL 3.5a to measure the degree of displacement. These results were compared against the original model to determine what level of error was introduced due to model simplification.

Three new eutardigrades, Doryphoribius longistipes sp. nov., Doryphoribius minimus sp. nov. and Doryphoribius tergumrudis sp. nov., are described from stream periphyton, rock lichen and cave soil and leaf litter samples collected in the limestone-based Cades Cove area of the Great Smoky Mountains National Park in eastern Tennessee, USA. Doryphoribius longistipes sp. nov. differs from other species mainly by the higher ratio of the secondary to the primary claw branches. Doryphoribius minimus sp. nov. differs from D. gibber, D. mariae and D. vietnamensis mainly by its smaller body size and different arrangement of dorsal gibbosities. Doryphoribius tergumrudis sp. nov. differs from D. evelinae by the absence of gibbosities and tubercles on legs I-III, the presence of lunulae and the absence of eyes. Additionally the three new species differ from other congeners by some other morphological and morphometric characters. Another species, Doryphoribius doryphorus Binda and Pilato, 1969, is a new record for Tennessee.

Parmi les agents qui modulent la dynamique des populations, le parasitisme est important mais souvent négligé. Il est urgent non seulement d’inventorier les différentes espèces de parasites, mais aussi de comprendre la sensibilité des hôtes à l’infection (notamment des bivalves) et étudier les interactions entre les parasites et les autres facteurs environnementaux. Par conséquent, cette thèse avait comme objectif principal de caractériser et de quantifier les communautés de trématodes (les plus abondants et répandus des macroparasites de bivalves dans les eaux côtières) qui infectent Cerastoderma edule (coque) et Donax trunculus (telline), deux des bivalves les plus importants au Portugal et en France d’un point de vue écologique et économique.Dans un premier temps, la dynamique des populations de bivalves a été étudiée en tenant compte de la relation entre la température et la période de recrutement et des effets en retour du recrutement sur la biomasse adulte. Pour cela, une base de données a été analysée couvrant 17 ans d’observations mensuelles d’une population de coques dans une réserve nationale (Banc d’Arguin, Arcachon, France). Ces observations à long terme ont montré que la durabilité d’une population de coques dépend du succès du recrutement. Pour les coques, le succès du recrutement a été montré comme étant en partie, mais pas totalement, dépendant de la température. Ainsi, la durée de vie d’une cohorte pourrait être estimée plus tôt, grâce à des indices se produisant en amont du recrutement. Suite à ces résultats, le rôle du parasitisme dans la dynamique des populations de bivalves a été étudié.Premièrement, en raison de leur forte pathogénicité pour les bivalves, une attention particulière a été accordée aux parasites Bucephalus minimus et Bacciger bacciger qui utilisent C. edule et D. trunculus, respectivement, comme premier hôte intermédiaire (où se développe le stade parasitaire sporocyste). [...]Deuxièmement, cette étude s’est concentrée sur l’infection des bivalves par les métacercaires, c’est-à-dire lorsqu’ils servent de second hôte intermédiaire dans le cycle de vie du parasite. […]Enfin, la sensibilité des bivalves à l’infection parasitaire a été évaluée expérimentalement lorsqu’ils sont confrontés à des facteurs liés au changement climatique (salinité, température et pH) et à la contamination (arsenic). Les résultats ont montré que l’exposition de l’hôte à des conditions de stress liées à des scénarios de changement global peut modifier le succès de l’infection parasitaire et altérer les réponse biochimiques de l’hôte.Les résultats présentés dans cette thèse ont amélioré la connaissance des effets de différentes variables sur les bivalves, soulignant le rôle crucial du parasitisme. S’ils sont appliqués, ces nouveaux concepts peuvent promouvoir la gestion durable des bivalves, une ressource marine importante, en augmentant son potentiel de production et donc son potentiel économique. / Among population dynamics drivers, parasitism is significant but often neglected. Beyond inventory of the various parasites, it is urgent to understand the susceptibility of hosts, namely bivalves, to infection, and to investigate the interaction among parasites and other environmental conditions.In this way, the present study aimed to characterize and quantify the trematode macroparasites, the most abundant and prevalent in coastal waters, infecting Cerastoderma edule and Donax trunculus, which are among the most ecologically important and economically explored bivalve species in Portugal and France.The first step was to study bivalve population dynamics, evaluating the relationship between temperature and recruitment timing and the reciprocal effects of recruitment on adult biomass. For this, a large database spanning 17 years of monthly observations of a cockle population inhabiting a national protected area (Banc d’Arguin, Arcachon, France) was analysed. Long-term observations showed that the sustainability of a cockle population is recruitment-success dependent. In cockles, recruitment success showed to be partly, but not only, dependent on temperature. Hence, the sustainability of a cohort could be set earlier, i.e. by processes happening before recruitment. Following this clue, the role of parasitism on the bivalve host population dynamics was explored.Firstly, due to high pathogenicity for bivalves, special attention was given to the parasites Bucephalus minimus and Bacciger bacciger which use C. edule and D. trunculus, respectively, as first intermediate hosts (where their sporocysts parasitic stage develops). […]Then, the study focused on metacercariae infection in its bivalve second intermediate host, a relationship that is usually reported as less deleterious. […]Lastly, the susceptibility of bivalves to parasites infection when challenged by climate change related factors (salinity, temperature and pH) and contamination (Arsenic) was experimentally assessed. Main results showed that hosts exposure to stressful conditions related to global change scenarios can modify the parasite infection success and induced host biochemical response alterations.The findings presented in this thesis improved the knowledge on the effects of different constraints on bivalves, highlighting the crucial role of parasitism. If applied, these new insights can promote the sustainable management of bivalves, such an important marine resource, with greater production and economic potential. / Entre os agentes que modulam a dinâmica populacional, o parasitismo é significativo masmuitas vezes negligenciado. É urgente não só inventariar as várias espécies de parasitas, bem comocompreender a suscetibilidade dos hospedeiros à infeção (nomeadamente os bivalves) e investigar ainteração entre os parasitas e outras condições ambientais. Pelo que, esta tese teve como objetivoprincipal caracterizar e quantificar os macroparasitas trematodes (os mais abundantes e prevalentesem águas costeiras) que infetam Cerastoderma edule (berbigão) e Donax trunculus (conquilha), doisdos bivalves mais importantes em Portugal e França tanto do ponto de vista ecológico comoeconómico.Primeiramente, a dinâmica populacional dos bivalves foi estudada, tendo em conta a relaçãoentre a temperatura e o período de recrutamento e os efeitos recíprocos do recrutamento nabiomassa de adultos. Para isso, foi analisada uma base de dados abrangendo 17 anos deobservações mensais de uma população de berbigões que habitam uma área nacional protegida(Banc d’Arguin, Arcachon, França). Estas observações de longa duração mostraram que asustentabilidade de uma população de berbigão é dependente do sucesso do recrutamento. Emberbigões, o sucesso do recrutamento mostrou ser em parte, mas não totalmente, dependente datemperatura. Por esta razão, a sustentabilidade de uma coorte pode estar a ser estabelecida maiscedo, isto é, por processos que acontecem antes do recrutamento. Seguindo esta pista, o verdadeiropapel do parasitismo na dinâmica populacional dos bivalves foi mais explorado.De seguida e devido à elevada patogenicidade para os bivalves, foi dada especial atençãoaos parasitas Bucephalus minimus e Bacciger bacciger que usam C. edule e D. trunculus,respetivamente, como primeiros hospedeiros intermediários (onde o estádio parasítico esporocisto sedesenvolve). […].Depois, este estudo focou-se na infeção dos bivalves por metacercariae, ou seja, quandoservem de segundos hospedeiros intermediários no ciclo de vida do parasita. […]Por fim, foi experimentalmente avaliada a suscetibilidade dos bivalves à infeção por parasitasquando desafiados por fatores relacionados com as alterações climáticas (salinidade, temperatura epH) e contaminação (Arsénio). Os resultados mostraram que a exposição dos hospedeiros acondições de stress relacionadas com cenários de alterações globais podem modificar o sucesso dainfeção parasitária e induzir alterações na resposta bioquímica do hospedeiro.As descobertas apresentadas nesta tese melhoraram o conhecimento dos efeitos dediferentes variáveis nos bivalves, salientando o papel crucial do parasitismo. Se aplicados, estesnovos pontos de vista podem promover a gestão sustentável dos bivalves, um recurso marinho tãoimportante, aumentando o seu potencial de produção e económico.