EASTERN" NIGHTHAWK 211 



vironment has been an important factor in the preservation of the 

 species. Chimneys have been used in America for centuries, but tlie 

 graveled roof on which the nighthawk builds its nest is a com- 

 paratively recent development. It was not until the middle of the 

 nineteenth century that the mansard and the flat type of graveled 

 roofs were introduced. It was not long after these first roofs were 

 built that the nighthawks discovered the possibilities of a new and 

 admirable type of nesting site. As early as 1869 W. P. Turnbull 

 wrote that the nighthawk was often seen high in the air above the 

 streets of Philadelphia and that their nests were frequently found 

 on the roofs of the warehouses of the city. Louis A. Zarega (1882) 

 reported finding them breeding on a roof on the north side of 7lst 

 street, Philadelphia, in June 1882. In 1870 and 1871 Dr. T. M. 

 Brewer (1874) found a number of instances of this bird nesting on 

 the flat mansard roofs of Boston, and a few years later it was dis- 

 covered nesting on the flat roofs of Montreal, Canada, by William 

 Couper (1876). In 1879 a pair of the birds built a nest on a roof 

 in the heart of the city of Cleveland, Ohio, and a few years later 

 E. Sterling (1885) observed three pairs nesting on a slate roof of a 

 large building near his study. Since 1880 there are innumerable 

 records of nighthawks that have deserted the rural districts to take 

 up their residence in the city. Today roof -nesting sites of the night- 

 hawk seem no more unusual than the nests of the chimney swift 

 built in our sooty chimneys. It is difficult to determine the factors 

 that have been instrumental in this radical change, for unlike the 

 case of the swift's hollow trees, there are just as many rocky 

 knolls, pebbly beaches, and barren fields as there were prior to the 

 appearance of the flat-roofed buildings. Although certain insects 

 such as flies and mosquitoes are abundant about our cities I do not 

 believe that the food supply has an important bearing on this ques- 

 tion, as has been maintained by certain observers. Even in the small 

 country villages, wherever there are graveled roofs there is the usual 

 quota of nighthawks. In these villages the environment, as far as 

 food for the nighthawk is concerned, is not different from regions 

 isolated from civilization. 



W. E. Saunders (1917) states that the young after their first 

 flight often land on the ground and he asks the question : "What 

 chance of survival is there for a young nighthawk on a city street 

 or vacant lot?" Mr. Saunders believes that the nighthawk has 

 steadily decreased in numbers since the bird has taken up its abode 

 in the city and states further that immigration is the only thino- 

 that keeps up the city population. To the contrary my observations 

 of the past 25 years in Maine indicate that the birds are not only 

 maintaining but are increasing their numbers. Furthermore, the 



