Rusty blackbird (Euphagus carolinus). Field Museum of Natural History, Chicago. Conservation status: vulnerable. E. carolinus ranges widely across the boreal zone of North America from New England, through Canada to Alaska and winters widely across the south-eastern United States. The population was estimated at 2 million individuals based on data from the North American Breeding Bird Survey collected during the 1980s and 1990s. This figure is likely to be a considerable overestimate as the species continues to decline. Estimates of the global decline since 1950 vary between 85% and 99%. The reasons for this dramatic decline remain poorly understood.