. American ornithology, for home and school . uction of anest early in March. As the season advances, and one sees the passing of countless featheredhosts, the summer residents dropping from their ranks as their summer homeis reached; the transient visitants pausing for a time only and then contin-uing their journey, the old vexed question as to the cause of this bi-annualmovement of the feathered tribes presents itself. So many are the difficul-ties and objections which present themselves, that a clear and concise so-lution of the problem seems impossible. I have discussed the question withma
. American ornithology, for home and school . uction of anest early in March. As the season advances, and one sees the passing of countless featheredhosts, the summer residents dropping from their ranks as their summer homeis reached; the transient visitants pausing for a time only and then contin-uing their journey, the old vexed question as to the cause of this bi-annualmovement of the feathered tribes presents itself. So many are the difficul-ties and objections which present themselves, that a clear and concise so-lution of the problem seems impossible. I have discussed the question withmany people who were well versed in bird study, as well as with many whotake but little interest in the birds. So many were the theories advanced present them all here, would be out of the question. But the most plausi-ble in the minds of many is that of food supply. Converse with some of the supporters of this theory and they will drawvour attention to the fact that when the ice leaves the rivers and lakes, we AMERICAN ORNITHOLOGY. 83. Photo from life by A. D. With Food for Her Young. 84 AMERICAN ORNITHOLOGY. notice that the geese and ducks put in an appearance, but not before. Alsoat this time we may expect the so-called enemy of the fisherman, the BeltedKingfisher. With the advent of the insect season, we note the arrival ofthose species which are wholly insectivorous. Again, in the fall, when thetemperature becomes such that the ground is hardened and the ice forms onthe water, we find that all the species that derive their food from the water,leave, and those whose nature it is to probe in the soft mud about the edgesof ponds and lakes, also leave as soon as the ground hardens. Now, while all these facts, for facts they are, together with many otherswhich are presented by the supporters of the food-supply theory, are unde-niably true, there are many objections to be answered before it will be gen-erally accepted as the one and only cause for migration
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