SAND DUNES AND SALT MARSHES 



bank swallow were to be seen. They were 

 constantly alighting on the bushes, fence 

 wires, and rails, particularly on those that 

 were over the water. Every few moments, 

 with a loud whirring noise from their many 

 wings, they would rise and wheel about in 

 bands, showing first dark and then white, as 

 they turned alternately their backs and their 

 breasts to the observer. Again they would 

 distribute themselves irregularly over the sky, 

 and a little later they would throw themselves 

 at the water with such violence that the sur- 

 face would be covered with little splashes, as 

 if a bombardment were in progress. 



Such exhibitions as this display not only the 

 social and gregarious characteristics of swal- 

 lows, but also the love of what appears to 

 deserve the name of play. It has been said, 

 as a reproach to their intelligence, that birds 

 do not play when young as do the young of 

 mammals, but the evolutions I have just de- 

 scribed seem to show a spirit of enjoyment or 

 play in flight, the natural exercise of birds, 

 just as do spurts of running, or wrestling or 

 butting contests in mammals. 



Another interesting trait of these flocking 

 birds is their habit of inspecting holes in posts 



114 



