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Mark-recapture Data (mark-recapture + data)
Selected AbstractsAsymmetric dispersal and survival indicate population sources for grassland butterflies in agricultural landscapesECOGRAPHY, Issue 2 2007Erik Öckinger We tested the hypothesis that populations in small habitat fragments remaining in agricultural landscapes are maintained by repeated immigration, using three grassland butterflies (Aphantopus hyperantus, Coenonympha pamphilus and Maniola jurtina). Transect counts in 12 matched sets of semi-natural pastures, and linear habitat elements proximate and isolated from the pastures showed that population densities of M.,jurtina and C.,pamphilus were significantly higher in pastures and in linear habitats adjacent to these than in isolated linear elements. A mark-recapture study in a 2×2 km landscape indicated that individuals of all three species are able to reach even the isolated linear elements situated at least 1 km from the grasslands. For two of the species, A.,hyperantus and C.,pamphilus, analysis of the mark-recapture data revealed higher daily local survival rates in the semi-natural pastures and more individuals dispersing from pastures to linear habitat elements. The proportion of old compared to young individuals of C.,pamphilus and M.,jurtina were significantly higher in linear elements than in semi-natural pastures, which suggests that butterflies emerging in pastures subsequently dispersed to the linear elements. In combination, these results suggest that semi-natural pastures act as population sources, from which adult butterflies disperse to surrounding linear elements. Hence, preservation of the remaining fragments of semi-natural grassland is necessary to keep the present butterfly abundance in the surrounding agricultural landscape. [source] Testosterone, growth and the evolution of sexual size dimorphismJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 8 2009R. M. COX Abstract The integration of macroevolutionary pattern with developmental mechanism presents an outstanding challenge for studies of phenotypic evolution. Here, we use a combination of experimental and comparative data to test whether evolutionary shifts in the direction of sexual size dimorphism (SSD) correspond to underlying changes in the endocrine regulation of growth. First, we combine captive breeding studies with mark-recapture data to show that male-biased SSD develops in the brown anole lizard (Anolis sagrei) because males grow significantly faster than females as juveniles and adults. We then use castration surgeries and testosterone implants to show that castration inhibits, and testosterone stimulates, male growth. We conclude by reviewing published testosterone manipulations in other squamate reptiles in the context of evolutionary patterns in SSD. Collectively, these studies reveal that the evolution of SSD has been accompanied by underlying changes in the effect of testosterone on male growth, potentially facilitating the rapid evolution of SSD. [source] Microgeographic population structure of brook charr: a comparison of microsatellite and mark-recapture dataJOURNAL OF FISH BIOLOGY, Issue 3 2003B. K. Adams Polymorphism at five microsatellite genetic markers (genotyped n = 496) and mark-recapture tagging data (tagged n = 9813) were used to define the population structure of brook charr, Salvelinus fontinalis from the Indian Bay watershed, Newfoundland, Canada. Despite the absence of physical barriers to migration among lakes, both genetic and tagging data suggest that brook charr in each lake represent reproductively isolated populations. Exact tests comparing allele frequencies, , (global value = 0·063), Rst (global value = 0·052), individual assignment tests, and Nei's genetic distance provided congruent estimates of population subdivision in agreement with the tagging data (only 2·2% of recaptures were lake-to-lake). The genetic structure of the brook charr populations corresponded with the geographic structure of the drainage basin on a qualitative level, although linear distance over water was not significantly correlated with the tagging data or the genetic distance measures. The agreement between the tagging and the genetic data suggest that microsatellite markers can be useful tools for defining real biological units. The results also suggest that brook charr exhibit microgeographic population structure at the watershed scale, and that this is the scale at which conservation and management of this salmonid might best be implemented. [source] Bayesian analysis of mark-recapture data with travel time-dependent survival probabilitiesTHE CANADIAN JOURNAL OF STATISTICS, Issue 1 2008Saman Muthukumarana Abstract The authors extend the classical Cormack-Jolly-Seber mark-recapture model to account for both temporal and spatial movement through a series of markers (e.g., dams). Survival rates are modeled as a function of (possibly) unobserved travel times. Because of the complex nature of the likelihood, they use a Bayesian approach based on the complete data likelihood, and integrate the posterior through Markov chain Monte Carlo methods. They test the model through simulations and apply it also to actual salmon data arising from the Columbia river system. The methodology was developed for use by the Pacific Ocean Shelf Tracking (POST) project. Analyse baye,esienne de donne,es de capture-recapture a, I'aide de probabilites de survie dependant du temps de deplacement Les auteurs généralisent le modèle de capture-recapture classique de Cormack-Jolly-Seber pour tenir compte de déplacements spatiaux-temporels signalés par des marqueurs (tels que des barrages). Les taux de survie sont modélisés en fonction de temps de déplacement parfois inobservables. Vu la complexité de la vraisemblance, ils optent pour une approche bayésienne fondée sur la vraisemblance des données complètes et intègrent la loi a posteriori par des méthodes de Monte-Carlo à cha,ne de Markov. Ils testent le modèle par simulation et l'utilisent pour l'analyse de données sur les saumons du réseau hydrographique de la Columbia. La méthodologie a été développée aux fins du projet POST (Pacific Ocean Shelf Tracking). [source] | ||||||||||