The Marsh Is a Hotel 29 



where the pellets had accumulated for years. There was the 

 fatal attraction of powerful beacon lights. Widespread natu- 

 ral catastrophes killed many: I recall the classical examples 

 of the sleet storm which destroyed hundreds of thousands of 

 snow buntings and of the tremendous loss of passenger 

 pigeons in a prairie storm, a loss so great that it certainly 

 hastened the total disappearance of this bird from the Amer- 

 ican scene. And the wildfowl had the gantlet of man's de- 

 struction to run. But though the losses might be high I saw 

 no evidence of fear or nervousness among the birds in the 

 marsh. 



Each fall I watched this arrival and departure of returning 

 migrants. It was only a microscopical section of what was in 

 effect an amazing transfer of whole wildlife populations for 

 some not-too-clear purpose. The birds came through singly 

 or in very small flocks instead of in the thousands that fol- 

 lowed the main fly ways. I speculated on the causes of this 

 annual movement and read the many attempts to answer, 

 none of which has been completely accepted. The most favor- 

 ably received idea attributes it to the necessity of leaving the 

 northern territory during the cold winters of the glacial age, 

 but that had been at least ten thousand years ago, and why 

 should the habit persist so strongly through the changed cli- 

 mate of centuries that it would still bring tiny western 

 sandpipers from northern South America to Alaska for the 

 purpose of mating and raising their young, a stay which 

 occupies only about a quarter of the calendar year? The 

 common tern nests as far north as British Columbia, then 

 winters as far south as the tip of South America. The tiny 

 rufous hummingbird plays about the marsh in summer and 

 is seen in Central America after migration. 



Why such tremendous trips? Food is said to have been 

 an important factor when the ice advance had blocked off 

 much previously available land. Many hold the theory that 

 birds go south to the lush wintering spots only because their 



