An interesting comparison of the flights of day and night migrants may be made through a consideration of the spring migrations of the blackpoll warbler and the cliff swallow. Both spend the winter as neighbors in South America, but when the impulse comes to start northward toward their respective breeding grounds, the warblers strike straight across the Caribbean Sea to Florida (Fig. 3), while the swallows begin their journey by a westward flight of several hundred miles to Panama (Fig. 4). From there they move leisurely along the western shore of the Caribbean Sea to Mexico, and, continuing to avoid a long trip over water, go completely around the western end of the Gulf of Mexico. This circuitous route adds more than 2,000 miles to the journey of the swallows that nest in Nova Scotia. The question may be asked: "Why should the swallow select a route so much longer and more roundabout than that taken by the blackpoll warbler?" The explanation is simple. 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 in favorable localities. The swallow, on the other hand, starts its migration several weeks earlier and catches each day's ration of flying insects during its aerial evolutions, while slowly migrating. The 2,000 extra miles flown along the insect-teeming shores of the Gulf of Mexico are exceeded by the great distances covered by these birds in normal pursuit of food. [Illustration: _Figure 4. Migration of the cliff swallow. A day migrant that, instead of flying across the Caribbean Sea as does the blackpoll warbler (see Fig. 3), follows the coast of Central America, where food is readily obtained._] Although most of our smaller birds make their longest flights at night, close observation shows travel is continued to some extent by day. During the latter half of a migratory season birds may show evidence of an overpowering desire to hasten to their breeding grounds. At this time flocks of birds maintain a movement in the general direction of the seasonal journey while feeding on or near the ground. Sometimes they travel hurriedly, and while their flights may be short, they can cover an appreciable distance in the course of a day. =SPEED OF FLIGHT AND MIGRATION= There is a widespread misconception among people concerning the speed at which birds can fly. One often hears stories of birds flying "a mile a minute." While undoubtedly some birds can and do attain this speed, such cases are exceptional, and it is safe to say that, even when pressed, few can develop an air speed of 60 miles per hour. Birds generally have two greatly differing speeds, one being the normal rate for ordinary purposes, and an accelerated speed for escape or pursuit. All birds, except the heavy-bodied, small-winged species such as auks, grebes, and other divers, have a reserve speed that may be double the normal rate.