@article {1237,
	title = {The ecology of Blackbird (<i>Agelaius</i>) social systems},
	journal = {Ecological Monographs},
	volume = {31},
	year = {1961},
	note = {Icteridae},
	pages = {285-312},
	keywords = {yesnest},
	author = {G. H. Orians}
}
