02541nas a2200217   4500008004100000245011700041210006900158300000900227490000800236520184100244653001502085653002502100653002602125653001802151653000902169653003002178653002402208100001902232700001802251856005402269       2018                        eng d00aPatterns and correlates of within-season breeding dispersal: a common strategy in a declining grassland songbird0 aPatterns and correlates of withinseason breeding dispersal a com  a1-140 v1353 a<p>Dispersal is a ubiquitous behavior with important consequences for gene flow, demography, and conservation. Some birds engage in between-year breeding dispersal, but the factors shaping variation in this behavior are not well understood. In mid-continental grasslands, preliminary evidence suggested that Grasshopper Sparrows (Ammodramus savannarum) dispersed not only between seasons, but also within breeding seasons&mdash;an apparently uncommon avian behavior. We studied a population of Grasshopper Sparrows breeding in northeastern Kansas, USA, to document the spatial and temporal patterns of within-season breeding dispersal in an experimentally managed tallgrass prairie from 2013 to 2015. We combined color-band resighting, territory mapping, and radio telemetry to quantify changes in territory density, turnover of territorial males, and dispersal distances. Density of Grasshopper Sparrows varied seasonally in management-specific ways, simultaneously increasing and decreasing in watersheds that differed in management regime. Turnover was unexpectedly high, with over half of territorial males being replaced each month. We documented over a third of males dispersing up to &sim;9 km between breeding attempts. Our study provides the first comprehensive description of the patterns of within-season breeding dispersal in a grassland songbird. Our results reveal the remarkable prevalence of within-season movement in this system and the relatively large distances over which birds disperse. Such mobility has important implications for survey design and habitat management, as birds select habitat at much larger spatial scales than is generally appreciated. These results also provide foundational information for tests of alternative hypotheses explaining the ecological and evolutionary basis for such movements.</p>10aGrasslands10ainter-patch movement10aintra-season movement10aKonza Prairie10aLTER10amid-season habitat shifts10aterritory switching1 aWilliams, E.J.1 aBoyle, W., A.  uhttp://www.bioone.org/doi/pdf/10.1642/AUK-17-69.1