Description: Perhaps the most abundant North American bird, and certainly one of the most studied, is the Red-winged Blackbird, which is also one of the most highly polygynous of all bird species. In northern and northeastern North America, males that have successfully claimed territories mate with 2 or 3 females; in dryer regions, where marsh insects may be more plentiful, the usual ratio is 3 to 6 females per territorial male. Up to 15 females have been observed on the territory of a single male, but the territory owner may not necessarily father all of the young on his territory. Females sometimes mate with several partners during a season or even during a single nesting attempt.