GUIDE TO THE ARRIVAL OF BIRDS
The dates given below are only intended to give the approximate time of arrival. They must not be taken too strictly as temperature and food conditions have much to do with the time of migrations. During December, January and February any of the birds mentioned in the chapter "Winter Birds," may be seen if one is in the right locality.
The last of February to the middle of March, prairie horned larks, horned larks (crows and winter birds are more numerous) and some straggler of the spring arrivals may be found.
Most years the early birds arrive individually or in small flocks. Following the very cold winter of 1917-18 the atmosphere became mild about March loth. On that day and the 21st there was an unusual arrival of bluebirds, robins, song sparrows and a few others.
During April there will be waves of migration. April Jo, 1915, a great wave came, and usually about the 19th there will be a large migration. May will have many interesting days, especially just before or after the loth, when the warblers are so numerous that one day is called warbler day. The banner record was May 20, 1917, when between sixty and seventy different species of birds were reported in this vicinity.
The best time for observation is early morning. If that is impossible, late afternoon is next best. Bird-lovers avoid windy weather, for then the feathered songsters are less numerous. During cold days or the early hours of cold mornings birds will be scarce. Some dull days, if mild, will be favorable. On a warm sunshiny morning following a migration a bird-lover has all an enthusiast could wish, but the next morning what a change — many have passed forward on their northern journey, for it is probable that the same individuals of a species do not tarry long in one locality during the flights north. In times of migration birds of the same species continue to arrive and depart until all have passed to their nesting ground. This accounts for birds of the same kind being seen several weeks in the spring. The same may be said of the autumnal flight south.