Vol. XXIII 



I'll Hi 



I Beyer, Allison, Kopman, liinls <>j Louisiana. 279 



in song for the first time; Myrtle Warblers are in song also, having 

 begun about a week earlier. White-throated Sparrows are begin- 

 ning to decrease, though Swamp Sparrows remain plentiful, and the 

 number of Savanna Sparrows is not appreciably affected. Late 

 transient Palm Warblers appear; sometimes they are in song. 



Excepting those species whose arrival during the preceding wave 

 is doubtful, a warm spell about April 1 brings few new species, but 

 generally a great abundance of the common kinds arriving during 

 the preceding period. The Yellow-billed Cuckoo is frequently an 

 exception to this rule. Transient Thrashers and Catbirds are 

 present. The first females and the bulk of males of (lie Orchard 

 Oriole arrive. The bulk of Tree Swallows arrive. The Black- 

 and-white Warbler, the Cerulean Warbler, the Ovenbird, and the 

 Redstart, species not much met with in southeast Louisiana in 

 spring, are perhaps most apt to be seen at this time. I'liu-bes and 



Ruby-crowned Kinglets depart. Myrtle Warblers decrease rapidly. 



Decidedly summery weather, sometimes sharply Separated from 



the preceding period by a fresher spell, is usual by April 10 or 12. 

 When the Yellow-hilled Cuckoo has not appeared earlier, it is. 



practically certain to be seen by this time. The Nighthawk ar- 

 rives, and in pine regions, the Chuck-will's-widow. An impor- 

 tant arrival in the fertile alluvial regions of southeast Louisiana is 

 the Yellow-breasted ( 'hat. 



Subsequent to this time, warm and summery weather prevails, 

 and diurnal tnigrational activity is not obvious except when the 



Weather fre8hen8. From tWO to three of these cooler periods are 

 likely to occur in the last half of April. Usually the most marked 

 is that occurring on or about April 20. Notable species forming 



the 'waves' at this time are the Baltimore Oriole, the Scarlel 

 Tanager, the Rose-breasted Grosbeak, the rarer thrushes, and 



the late transient warblers, especially of the genus I >cii<lr<>ira. 



(See Kopman, Auk, Jan., L904, pp. 45-50.) The maximum 



abundance of Barn Swallows is reached at this lime, and the first 



Black-throated Buntings are seen. 



Sometimes in place of the diurnal appearance of migrants after 

 April 20, and sometimes in connection with it, occur exceedingly 

 heavy nocturnal flights on hot nights with electric storms. 



As far as transients are concerned the sequence of migrational 



