id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
inhs-272	Smith, Frank	Records of Spring Migration of Birds at Urbana, Illinois, 1903-1922	1931	15	.pdf	application/pdf	4050	171	64	In the latter of these two papers (Illinois Birds as Travellers) there are also memoranda on winter homes of certain kinds of Illinois birds and on the routes followed in the journeys to and from them. In a study of the bird fauna of a region like the one under con- sideration, one must expect to deal with some species of which speci- mens are rarely seen, and not infreiiuently there will be but one or two records in a season and for some s]iecies but one or two records for the entire ]ieriod, Such records may be of but little use in an at- tem])t tt) determine the earliest and latest limits of a normal migration ])eriod for the species.	cache/inhs-272.pdf	txt/inhs-272.txt