THE BIRDS OF NEW JERSEY. 21 



Among the water birds the Bittern, Woodcock, Wil- 

 son's Snipe, Spotted Sandpiper and the Rails migrate ex- 

 clusively by night, while the other species seem to move 

 by day or night, according to circumstances, most diving 

 birds migrating along the coasts by day but making their 

 overland journeys by night. 



From an examination of the foregoing lists it will be 

 seen that the more timid, shelter-loving birds migrate at 

 night, and the bolder species, which are strong of flight 

 or which associate in flocks, migrate by day. The reasons 

 for this can easily be seen in the foUowing quotation from 

 Mr. Brewster's paper on Bird Migration: "Timid, seden- 

 tary, or feeble-winged birds migrate by night because they 

 are either afraid to venture oh. long, exposed journeys by 

 daylight, or unable to continue these journeys day after 

 day without losing much time in stopping to search for 

 food. By taking the nights for travelling they can de- 

 vote the days entirely to feeding and resting in their 

 favorite haunts. Good examples are Thrushes (except 

 the Eobin), Wrens, Warblers and Vireos. Bold, restless, 

 strong-winged birds migrate chiefly, or very freely, by 

 day because, being accustomed to seek their food in open 

 situations, they are indifferent to concealment, and being 

 further able to accomplish long distances rapidly and with 

 slight fatigue, they can ordinarily spare suflicient time by 

 the way for brief stops in places where food is abundant 

 and easily obtained. * * * Excellent examples are 

 the Robin, Horned Lark and most Icteridae. Birds of 

 easy, tireless wing, which habitually feed in the air or 

 over very extensive areas, migrate exclusively by day, 

 because being able either to obtain their usual supply of 

 food as they fly or to accomplish the longest journeys so 

 rapidly that they do not require to feed on the way, they 

 are under no necessity of changing their usual habits. 

 The best examples are Swallows, Swifts and Hawks. 

 Nocturnal and crepuscular birds, at least migratory 

 gpecies, are all strong-winged and accustomed to seek 



