Breeding site fidelity and its effect on reproductive success was investigated in two diving ducks species, i.e. Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula) in the Trebon region and the surroundings using caught and individually marked females, searching for nests, and monitoring of marked individuals and its broods. In both studied species, the fidelity ratio (apparent survival, MARK software) was around 65 %. Evaluating the influencing factors, impact of previous reproductive success in the phase of rearing ducklings was found to be the only one statistically significant factor. Furthermore, we compared reproductive parameters (i.e clutch size, laying date, reproductive success) in the first and subsequent year of study. The statistically significant relationship was found between the timing of nesting in the first and in any subsequent year in the Tufted Duck . When comparing the reproductive success in relation to hatched or unhatched clutches and reared or not reared ducklings, we do not confirm any significant shift. Successful females were not able to improve or even repeat their reproductive success in the following years, which could result in subsequent lower degree of fidelity. Subsequently, there is a female dispersion and reduction of the reproductive success of...

The requirements of true frogs on breeding sites were monitored at 19 locations in the Hradec Králové Region and the Central Bohemia Region and Vysočina Region. Specific sites were selected according to the high variability. Breeding sites are mutually different representation of true frogs, water volume, depth, water and surrounding vegetation. The data of oviposition three different species of czech frogs - moor frog (Rana arvalis), agile frog (Rana dalmatina) and common frog (Rana temporaria) - were collected in the spring months, from the end of March until the end of April, from 2012 to 2015. During this period were collected data from 927 egg clutches of these species. The data were obtained by non-invasive way - measuring of inividual clutches directly on the reproductive site. At each breeding site was also recorded the required parameters of the breeding pond and the surrounding environment (presence of true frogs, the water volume and depth of the pond, the presence and density of aquatic vegetation, surrounding vegetation, air and water temperature, pH value of water, etc.). The results presented in this work confirm that the three species of true frogs have, in some parameters, different standards to select of breeding sites. This clarification of species- specific claims is also...

I conducted demographic and behavioral studies of Western Sandpipers (Calidris mauri) breeding on the Yukon-Kuskokwim River Delta, Alaska (1998-2005). In chapter one, I estimated apparent annual survival (product of true survival and site fidelity) while correcting for the probability of encounter for 237 males and 296 females. Overall return rates (individual returned to the site in a subsequent season) were lower for females (40%) than males (65%), as was apparent annual survival (± SE, females = 0.65 ± 0.05, males = 0.78 ± 0.03), and encounter rate (females = 0.51 ± 0.07, males = 0.74 ± 0.04). In chapter two, I examined the effects of mate and site fidelity on nesting success (N = 430 nests). Annual divorce rate ranged between 37-83%, with 17-63% of pairs reuniting annually. Reuniting pairs initiated clutches earlier than newly formed pairs, and clutches that were initiated early in the season had higher nest success rates compared to late-season nests. When I controlled for clutch-initiation date, nests tended by individuals with prior breeding-site experience had higher daily survival rates compared to birds breeding at the site for the first time. The effect of site experience was greater for males than females. In chapter 3, I reported that Western Sandpipers exhibited aggregated breeding behavior on a 36 ha plot. Breeding aggregations occurred when dominant and/or older individuals excluded younger, subordinate individuals from preferred habitat. The pattern of habitat occupancy conformed to an ideal despotic distribution with aggregated nesting birds in less preferred habitat experiencing lower reproductive success. In chapter 4, I described and demonstrated the form and function of parent-chick communication in the Western Sandpiper. Through experimental playback of adult vocalizations to chicks in the field, I demonstrated: (1) chicks respond to the alarm call by vocalizing relatively less often and moving away from the signal source, (2) chicks respond to the gather call by vocalizing relatively more often and moving toward the signal source, (3) and chicks respond to the freeze call by vocalizing relatively less often and crouching motionless on the substrate for extended periods of time. I also describe two distinct chick vocalizations (chick-contact and chick-alarm calls). / Ph. D.

La Fièvre de la Vallée du Rift (FVR) est une zoonose observée pour la première fois au Kenya en 1930 qui s'est peu à peu propagée à la plupart des pays d'Afrique. La FVR est une maladie à transmission vectorielle dont le virus appartient au genre Phlebovirus de la famille des Bunyaviridæ. En Afrique de l'Est, l'émergence de foyers est prédite par des modèles statistiques, ce qui n'est pas le cas en Afrique de l'Ouest où les facteurs et les mécanismes en jeu sont encore mal définis. L'objectif de cette thèse est d'identifier les facteurs et les processus épidémiologiques expliquant l'émergence de foyers de FVR au Sénégal, en mettant en œuvre une approche éco-épidémiologique centrée sur les principaux moustiques vecteurs du virus. Par l'étude de variables environnementales et climatiques et par leur exploitation dans des modèles mathématiques, nous avons tenté de répondre à deux questions épidémiologiques majeures : (1) quelles sont les zones potentiellement à risque, et (2) quelles sont les périodes favorables à l'apparition de foyers. L'étude a été menée à l'échelle locale, dans une zone d'environ 10 km2 autour du village de Barkedji situé dans la région sylvo-pastorale du Ferlo.Pour localiser les zones à risque de transmission du virus, nous utilisons la télédétection et l'analyse paysagère afin de caractériser l'environnement favorable aux deux principaux candidats vecteurs du virus, Aedes vexans et Culex poicilipes. Pour identifier les périodes à risque, nous avons développé un modèle d'abondance de populations de moustique des deux espèces vectrices prenant en compte la dynamique des gîtes larvaires (les mares), et dont les simulations ont été validées avec des données de terrain de capture de moustiques. Pour se faire, nous avons dû préalablement développé un modèle dynamique de hauteur d'eau des mares temporaires, modèle calibré et validé à partir de données de terrain et de données d'observation de la Terre.Les résultats de l'analyse paysagère ont confirmé que les milieux favorables aux vecteurs de la maladie pouvaient être caractérisés par télédétection. Ils ont aussi mis en évidence l'importance des mares et de la densité de végétation environnante, et ont abouti à une cartographie de l'hétérogénéité spatiale du risque de circulation de la FVR. Les résultats de l'analyse temporelle ont montré que les années de circulation active du virus coïncidaient avec les années pour lesquelles les deux espèces de moustiques étaient présentes en forte quantité. On observe ainsi deux années à très forte densité des deux moustiques vecteurs, en 1987 et en 2003, correspondant aux années d'épidémie/épizootie les plus importantes dans la région. / The Rift Valley fever (RVF) is an arboviral zoonosis, first identified in Kenya in 1930, which has spread over many African countries. The RVF virus (RVFV) is a mosquito-borne virus member of the family Bunyaviridae, genus Phlebovirus. Statistical models that are used for predicting RVF outbreaks in East Africa do not work in West Africa where the factors and processes involved are still not well described. The aim of this thesis is to identify the factors and epidemiological processes that explain the emergence of RFV outbreaks in Senegal. To achieve that, we have chosen an eco-epidemiological approach targeted on the main candidate mosquito vectors of the RFV virus. By using the environmental and climatic variables and by their exploitation in mathematical models, we tried to answer two major epidemiological questions: (1) where are the potential zones at risk? And, (2) when are the periods favourable to RFV outbreaks?The study has been carried out at a local scale, in an area of about 10 km2 centred on the village of Barkedji in the pastoral Ferlo region in northern Senegal.When identifying risk areas for virus transmission, we used remote sensing and landscape analysis to characterize favourable environments fot the two main candidate vectors, Aedes vexans and Culex poicilipes (Diptera: Culicidae). For predicting risk of RVF outbreaks, we developed a mosquito population model for the two vector species taking into account the dynamics of the ponds as breeding sites. The results of the simulation have been validated with captured mosquito field data. This required the prior development of a temporary pond dynamics model that was calibrated and validated with field and remote sensing data.The results of the landscape analysis confirmed that favourable environments for the mosquito vectors of the RVF could be characterised by remote sensing. The importance of the ponds and the surrounding vegetation density was also highlighted, allowing to map the spatial heterogeneity of RVF circulation risk. The results of the mosquito model simulations showed that years of active virus circulation matched the years when both vector species were densely present. Indeed, the simulations showed high mosquito densities in 1987 and 2003, which correspond to the most important epidemic and epizootic events in that region.