Molecular-genetic technology and statistical methods based on principles of population genetics provide valuable information to wildlife managers. Genetic data analyzed in a hierarchical, spatial context among individuals and among populations at micro-and macro-geographic scales has been widely used to provide information on the degree of population structure and to estimate rates of dispersal. Our goals were to (1) provide an overview of spatial statistics commonly used in empirical population genetics, and (2) introduce analytical designs that can be employed to extend hypothesis-testing capabilities by incorporating space-time interactions and by using information on habitat quality, distribution, and degree of connectivity. We show that genetics data can be used to quantify the degree of habitat permeability to dispersal and to qualify the negative consequences of habitat loss. We highlight empirical examples that use information on spatial genetic structure in areas of harvest derivation for admixed migratory species, wildlife disease, and habitat equivalency analysis.

Quantifying the spatial genetic structure of highly vagile species of birds is important in predicting their degree of population demographic and genetic independence during changing environmental conditions, and in assessing their abundance and distribution. In the western Arctic, Lesser Snow Geese (Chen caerulescens caerulescens) provide an example useful for evaluating spatial population genetic structure and the relative contribution of male and female philopatry to breeding and wintering locales. We analyzed biparcntally inherited microsatellite loci and maternally inherited nitDNA sequences from geese breeding at Wrangel Island (Russia) and Banks Island (Canada) to estimate gene flow among populations whose geographic overlap during breeding and winter differ. Significant differences in the frequencies of mtDNA haplotypes contrast with the homogeneity of allele frequencies for microsatellite loci. Coalescence simulations revealed high variability and asymtnetry between males and females in rates and direction of gene flow between populations. Our results highlight the importance of wintering areas to demographic independence and spatial genetic structure of these populations. Malc-tnediated gene flow among the populations on northern Wrangel Island, southern Wrangel Island, and Banks Island has been substantial. A high rate of female-mediated gene flow from southern Wrangel Island to Banks Island suggests that population exchange can be achieved when populations winter in a common area. Conversely, when birds from different breeding populations do not share a common wintering area, the probability of population exchange is likely to be dramatically reduced.Flujo Génico Intercontinental entre Poblaciones de Chen caerulescens caerulescens del Oeste del ÁrticoResumen. Cuantiñcar la estructura genética espacial de especies de aves con alta movilidad es importante para predecir el grado de independencia demográfica y genética de las poblaciones en momentos de condiciones ambientales cambiantes, y para evaluar su abundancia y distribución. En el oeste del Ártico, Chen caerulescens caerulescens representa un ejemplo útil para evaluar la estructura genética poblacional en el espacio y para estimar la contribución relativa de la filopatria a los sitios de cria y de invernada por parte de los machos y de las hembras. Utilizando muestras de aves reproductoras de las islas de Wrangel (Rusia) y Banks (Canadá), analizamos loci microsatelitales heredados biparentalmente y secuencias de genes de ADNmt heredados por la linea materna para estimar el flujo genético entre poblaciones cuyas distribuciones geográficas se superponen durante la época de cria pero difieren en el invierno. Las diferencias significativas en las frecuencias de haplotipos de ADNmt contrastan con la homogeneidad en las frecuencias alélicas de los microsatélites. Las simulaciones basadas en coalescencia revelaron una alta variabilidad y asimetría entre machos y hembras en las tasas y en la dirección del flujo génico entre poblaciones. Nuestros resultados...

Many states have established special harvest seasons and hunting zones to target overabundant populations of temperate‐nesting Canada geese (Branta canadensis) and protect less abundant northern‐nesting populations of Canada geese and cackling geese (B. hutchinsii). To meet management needs for spatially and temporally explicit harvest estimates, we utilized established methods of genetic stock identification and standardized harvest sample collections to estimate proportional contributions of cackling (B. h. hutchinsii) and Canada geese (B. c. maxima and B. c. interior) to 5 consecutive annual harvests (1998‐2002) in Michigan, USA. Harvest samples (n = 2,272) were analyzed for several seasons at statewide, regional, and local spatial scales. We expanded upon previous studies that used genetic methods to monitor cackling goose and Canada goose harvests by analyzing harvests within regional and local goose management areas. Likelihood ratio tests were also employed to compare harvest composition among spatial and temporal sampling groups. Tests revealed that proportions of giant and interior Canada geese within local harvests varied significantly during the fall in different hunt zones of Michigan and during different time periods. Adaptive management of temperate‐nesting and northern‐nesting geese would benefit from accurate estimates of harvest composition, as provided by genetic‐based methods. Quantification of changes in harvest composition as a function of variation in season opening date and duration, and bag limits can provide valuable insight into goose migratory behavior and population dynamics. Harvest composition estimates may be used to predict impacts of management prescriptions on mortality rates of specific breeding populations.

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