Rusty blackbird (Euphagus carolinus) populations have declined dramatically since the 1970s and the cause of decline is still unclear. As is the case for many passerines, most research on rusty blackbirds occurs during the nesting period. Nest success is relatively high in most of the rusty blackbird’s range, but survival during the post-fledging period, when fledgling songbirds are particularly vulnerable, has not been studied. We assessed fledgling and adult survivorship and nest success in northern New Hampshire from May to August in 2010 to 2012. We also assessed fledgling and adult post-fledging habitat selection and nest-site selection. The likelihood of rusty blackbirds nesting in a given area increased with an increasing proportion of softwood/mixed-wood sapling stands and decreasing distances to first to sixth order streams. Wetlands were not selected for nest sites, but both adults and fledglings selected wetlands for post-fledging habitat. Fledglings and adults selected similar habitat post-fledging, but fledglings were much more likely to be found in habitat with an increasing proportion of softwood/mixed-wood sapling stands and were more likely to be closer to streams than adults. No habitat variables selected during nesting or post-fledging influenced daily survival rates, which were relatively low for adults over the 60-day study periods (males 0.996, females 0.998). Fledgling survival rates (0.89) were much higher than reported for species of similar size.

The rusty blackbird (Euphagus carolinus) is a species of conservation concern throughout its range because of rapid population decline. During winter, relatively large flocks are in suburban landscapes within the Georgia and South Carolina Piedmont Plateau of the southeastern United States. We studied radio‐tagged blackbirds within flocks that moved daily among 3 distinct patch types: pecan (Carya illinoinensis) and small‐seeded oak (Quercus spp.) groves, shallowly flooded forested wetlands, and residential areas landscaped with turf grass. The patch types used for foraging have varying availability of invertebrate and mast food. We investigated the relationship between daily observations of blackbird flocks and previous, current, and oncoming short‐term weather. Suburban landscapes with the appropriate configuration of shallow wetland, residential lawns, and mast grove patches within a 153–415‐ha area, the size of patch aggregations in this study, likely constitute high quality wintering areas for this species. Blackbird flocks were 1.6–1.8 times more likely to be observed foraging in wetlands with each 10°C increase in current temperature, 1.5 times more likely in wetlands for every 5 days with no previous precipitation, and 3.2 times more likely in wetlands with every 10 extra hours of oncoming cold weather. Blackbirds were 4.1–4.5 times less likely to be observed foraging in forested wetlands with every 5‐mm increase in current precipitation. Blackbirds were 2.2 times more likely to be observed in mast groves with every 5‐mm of oncoming precipitation. Radio‐tagged blackbirds used pecan groves for foraging in 2011 but not 2012, which was an overall warmer winter. Pecan groves may be a sporadically used component of a combination of foraging patches that are rarely near flooded forested wetlands or residential areas. Our results can be used to identify and conserve patch components used by rusty blackbird flocks during winter in suburban nature parks and greenways. © 2018 The Wildlife Society.