466 BULLETIN" 17 9, UNITED STATES NATIONAL MUSEUM 



in the fact that the cliff swallow is a day migrant and catches its daily 

 ration of winged insects as it travels slowly along in the proper direc- 

 tion, which obviously it could not do if its route were across the 

 Gulf of Mexico," By the first week of May the cliff swallows have 

 reached New England, and at about the same time they appear in 

 Alaska again, forcibly emphasizing the rapidity of the migration wave 

 along the Pacific coast and the comparatively slow progress along the 

 Atlantic seaboard. Lincoln makes a very illuminating comparison of 

 the migration of the cliff swallow and the blackpoll warbler as follows : 



During the winter months these species are together in South America. Upon 

 the approach of spring, bringing with it the impulse to start northward toward 

 their respective breeding grounds, the warblers strike straight across the Carib- 

 bean Sea to Florida, while the swallows begin their journey by a flight of several 

 hundred miles westward to Panama. Thence they move leisurely along the 

 western shore of the Caribbean Sea to Mexico, and as if to avoid a long trip 

 over water, go completely around the western side of the Gulf of Mexico. By 

 making this long circuitous flight, swallows that nest in Nova Scotia add more 

 than 2.000 miles to the length of their migratory journey. The question may be 

 asked — Why should the strong-winged cliff swallow use a route that is so much 

 longer and more roundabout than that followed by the Black-Poll Warbler? 

 The explanation is simple as the swallow is a day migrant while the warbler 

 travels at night. The migration of the warbler is made up of a series of long 

 nocturnal flights, alternated with days of rest and feeding. The swallow, on 

 the other hand, starts its migration several weeks earlier and catches each day's 

 ration of flying insects during a few hours of aerial evolutions, which at the 

 same time carry it slowly in the proper direction. Flying along the insect- 

 teeming shores of the Gulf of Mexico, the 2,000 extra miles that are added to 

 its migration route are but a fraction of the distance that these birds actiaally 

 cover in pursuit of their food. 



While a considerable number of cliff swallows have been banded 

 there are not sufficient returns to assist in plotting the actual migra- 

 tion routes. One record, however, is of interest: A cliff swallow 

 banded at Dell Rapids, S. Dak., on June 14, 1937, was captured and 

 released with its band at Ghent, W. Va,, on July 16, 1937. This bird 

 in the course of a month flew approximately 1,200 miles in a south- 

 easterly direction. If we take into account its erratic and circuitous 

 flights in quest of insects during its journey, it probably averaged 

 more than 100 miles a day. Its flight to the eastward is interesting, 

 since it migrates to its winter home in South America via Mexico and 

 Central America. One record, however, is not sufficient to indicate 

 that many individuals travel so far out of bounds of a direct route. 



The cliff swallow migrates in flocks, and practically all the reports 

 of the large numbers seen throughout the migration route mention 

 the association of the cliff swallow with barn and tree swallows as well 

 as other members of the family. At Rowland's Marsh in the Sierras, 

 Ray (1918) saw on May 27, 1912, at least a thousand cliff swallows 



