The behaviours of eastern chipmunks (Tamias striatus) in response to aerial predators were studied in the field using trained kestrels (Falco sparverius) flying over a food patch where animals of known gender, age and burrow location categories were foraging. Their typical response was to flee toward a nearby refuge while producing a trill. After a few seconds, chipmunks usually emerged and started to produce long (but sometimes interrupted) series of chucks while facing the predator. Acoustical analysis showed that the trill consisted of a rapid series of usually high pitched and variable notes while most chucks consisted of two partially overlapping components differing mainly in frequency range. No differences were observed between individuals of different categories for most antipredator responses. Various observations suggest that the trill functions to startle the predator and that the chuck deters the predator from hunting in the area.

Chipmunk antipredator calls were examined during the summers of 1990 and 1991. The structural characteristics of the three calls, chipping, chucking and the trill, were obtained through taped recordings and sonagraphic analysis. Behavioural observations indicated that chucking by choruses of individuals occurs in the presence of aerial predators, chipping by choruses of individuals occurs in the presence of terrestrial predators and the trill is given by single individuals when fleeing from predators. / Experiments were carried out to determine the function of the trill and chipping. Demographic and contextual effects indicate that the trill is in part a call which functions to warn kin but may also indicate to conspecifics that the caller has escaped into a refuge. An experiment with a tethered cat concluded that chipping is likely to function to deter predators from hunting in the area. This is done through vocal mobbing by several individuals whose home ranges overlap.

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The distribution of the cliff chipmunk in Idaho was previously considered to include only the Raft River Valley and the Goose Creek Basin. A pilot study was conducted in 2003 and 2004. Thirty-five cliff chipmunk presence locations and 124 absence locations were recorded. Habitat variables of elevation, slope, deviation from south, distance to water, and vegetation type were extracted for all of the absence and presence points by means of GIS analysis. The data were analyzed by implementing a classification tree, and a "GIS habitat association model" was created. The model was tested in 2005, and the overall model accuracy was 77.5%. The study extended the known cliff chipmunk range in Idaho west to Rock Creek, Twin Falls County, east to Weston Canyon, Franklin County, and north to the Cotterel Mountains, Cassia County. Monitoring current known locations and searching for new locations to further refine 11 understanding of the species' distribution and to determine the actual population status of cliff chipmunks in Idaho are recommended.

Det här examensarbetet utvärderar spelutveckling i HTML5. Detta innebär utveckling i JavaScript, CSS samt HTML med utnyttjande av den nya teknologin som medföljer HTML5 märkeringen. I detta fall är teknologin canvas-element som ritar ut 2-D grafik. Två implementationer av ett motorcykelspel har utvecklats med fysikmotorerna Box2D respektive Chipmunk. Målet med arbetet var att utvärdera bästa val av fysikmotor vid utveckling av ett spel i 2-D med krävande fysik i HTML5 till mobil.

La variation de la diversité des communautés d’hôtes réservoirs peut modifier le risque de maladies impliquant ces espèces. En particulier, l’introduction d’une espèce potentiellement réservoir est susceptible d’augmenter le risque de maladie, en agissant comme un réservoir supplémentaire et/ou en amplifiant la circulation des agents pathogènes chez les réservoirs autochtones. L’objectif du travail de thèse est de quantifier la contribution, d’une espèce introduite, le tamia de Sibérie (Tamias sibiricus barberi), au risque d’une maladie multi-hôtes, la borréliose de Lyme, due à des bactéries appartenant au complexe d’espèces Borrelia burgdorferi sensu lato et transmises par des tiques, principalement Ixodes ricinus en Europe. Dans un premier temps, nous avons testé si le tamia est un réservoir compétent pour la maladie de Lyme en milieu naturel, c'est-à-dire s’il est capable de transmettre B. burgdorferi sl aux tiques I. ricinus et de maintenir l’infection. Le tamia est fortement infesté par les tiques et infecté par les bactéries et il peut transmettre B. burgdorferi sl aux tiques. Nos résultats ne montrent pas clairement que le tamia peut maintenir l’infection. Une des deux composantes du risque de la maladie de Lyme pour l’homme est le risque acarologique, c'est-à-dire la densité de nymphes infectées en quête d’hôtes. Dans un deuxième temps, nous avons calculé la contribution du tamia au risque acarologique et l’avons comparé à celles du campagnol roussâtre (Myodes glareolus) et du mulot sylvestre (Apodemus sylvaticus), réservoirs avérés de B. burgdorferi sl. Puis, nous avons étudié la variation temporelle de la contribution du tamia et testé si sa présence influençait la contribution des réservoirs rongeurs natifs. Pour calculer la contribution au risque, nous avons utilisé deux approches, l’une basée sur des captures des rongeurs, et l’autre sur l’identification des espèces hôtes sur lesquelles se sont gorgées les tiques. Le tamia produit plus de nymphes infectées à l’affût que le campagnol et le mulot. La contribution du tamia varie entre années suivant la densité de tamias et intra-années suivant la disponibilité en tiques. Sa plus forte infestation par I. ricinus et infection par B. burgdorferi sl, que les rongeurs natifs, peuvent être expliquées par sa plus forte exposition aux tiques. En conclusion, le tamia semble un réservoir compétent pour B. burgdorferi sl, avec une forte contribution au risque acarologique et une amplification possible de la circulation des pathogènes dans les communautés natives. Sa présence peut augmenter le risque pour la borréliose de Lyme chez l’homme en augmentant la prévalence d’infection des nymphes, mais pas les densités de nymphes à l’affût. / The variation of the composition of host communities can modify the risk of diseases involving these species. In particular, the introduction of a potentially reservoir species may increase the disease risk, by acting as an additional reservoir or by amplifying the circulation of pathogens in the native reservoirs. We quantified the contribution of an introduced species, the Siberian chipmunk (Tamias sibiricus barberi), to the risk of a multi-host vector-borne disease, Lyme borreliosis (LB), due to bacteria that belong to the Borrelia burgdorferi sensu lato complex and transmitted by bites of hard ticks, especially by Ixodes ricinus ticks in Europe. First, we verified if the Siberian chipmunk is a competent reservoir host for LB in the field, by testing if chipmunks can transmit B. burgdorferi sl to I. ricinus ticks and maintain the infection. Chipmunks were highly infested by ticks and infected by B. burgdorferi sl, and they are able to transmit the bacteria to ticks. Our results did not show clear maintenance patterns. Second, one of the parameter of LB risk for human is the acarologic risk, which is the density of infected questing nymphs. We evaluated the contribution of chipmunks to this risk and compared it with the one of bank voles (Myodes glareolus) and wood mice (Apodemus sylvaticus), two known reservoir rodents. Moreover, we studied the variation of the contribution. We used two approaches, the one based on captures of rodents and the other one on host-blood meal analysis of questing nymphs. Chipmunks produced more infected nymphs than voles and mice. The contribution of chipmunks varies between years according to chipmunk density and during the year according to tick availability. The higher infestation by I. ricinus and infection by B. burgdorferi sl of chipmunks in comparison to native reservoir rodents, could be due to its higher exposition to ticks. As Siberian chipmunk seems to be a competent reservoir host for LB with strong contribution, they can “spillback” infection to native communities and increase the risk for LB to humans by increasing infection prevalence in nymphs, but not nymph density.