|90 BANK SWALLOW OR SAND MARTIN. 



hundreds of pairs about their breeding places, passing, repassing, and cross- 

 ing each other in various ways, you almost wonder that they never come 

 into collision with each other. The slightest movement in any direction 

 seems sufficient to enable them to overtake and secure their prey; and they 

 less frequently than any other species follow an insect upward to any great 

 distance. Like all other Swallows, they drink and bathe on wing. 



Their migrations are performed by day, although perhaps continued by 

 night, and their movements are more desultory and rather slower than those 

 of other Swallows. It is rare to observe them in great flocks at that time, 

 their associations not being apparently formed until they reach the countries 

 in which they spend the winter months. Their flight, when they are thus 

 travelling, is continued rather low over the land or the water; and as in 

 America they retire to a less distance southward than our other Swallows, 

 they are not unfrequently seen to linger behind the rest. In South Carolina, 

 indeed, I have seen some in November. 



In summer and autumn they roost in the holes excavated for their nests; 

 but in winter, at least in the Floridas, they always repose at night among the 

 tall grass of the salt marshes, making choice of situations sheltered by the 

 winds and not liable to be overflowed. At this time they keep together in 

 large bodies while searching for food. I have several times accidentally 

 crossed their roosting places, which I at once recognised by the quantity of 

 their dung attached to the blades, and lying on the ground, and from which 

 I infer that they rest clinging to the plants. 



At the first appearance of spring they leave their winter quarters in pairs, 

 or singly, or in very small flocks; but they follow each other so closely in 

 this manner as to form an almost continued line of march. I had the plea- 

 sure of observing this to be the case with the Barn Swallow also, whilst I 

 was proceeding toward the Texas, when that species was advancing in a con- 

 trary direction. 



Although small, the Sand Swallow is a rather hardy bird; for I observed 

 that the transient cold weather that at times occurs in the Floridas at night, 

 seldom forces them to remove farther south. On one occasion, however, 

 when the ice was about the thickness of a dollar, many were found dead 

 along the shores, as well as floating on the water, whilst the rest appeared in 

 great perturbation, wending their way in a hurried manner toward the 

 warmer parts of the country, and taking advantage of every spot that afford- 

 ed them more warmth, such as the borders of woods, and high banks of 

 streams. I am, however, of opinion that the inclemency of the weather at 

 times proves to be the greatest evil these birds have to encounter, especially 

 when in early spring they are moving northward, and occasionally meet with 

 a sudden change from temperate to cold. Even in the places selected for 



