Extracts from Diary of Otto Widmann 15 



are already coming over the river; a few voices only, 

 then more and more, and now the whole air is filled with 

 the short calls of Progne. They seem to he all around 

 us, below and above, but we may strain our eyes in all 

 directions, not a single bird can be discovered ; it is too 

 dark and the birds are too high above us. A few minutes 

 later the bulk has passed, but it is getting lighter and we 

 are able to see a few loiterers, mere dots passing the 

 zenith, following the others in a northwesterly or west- 

 erly direction. A few minutes more the last will be gone 

 and no Martin will be seen at this place before 5 P. M. 



After migration has thus begun it will be good for 

 us to visit the scene of rendezvous every day. The Mar- 

 tins begin to arrive at 5 P. M. ; they arrive mostly low 

 above the water, comparatively few are coming at some 

 height. As soon as a few hundred are together they 

 begin to sit down on the sand. In the beginning they are 

 pretty restless, changing their places every few minutes, 

 sometimes flying up in a cloud to settle dovm. at or near 

 the same spot again. If we are watching them now from 

 a place south of the bar we notice that not all settle down 

 again. After swinging a few circles, part of the flock 

 detaches itself from the rest, and, heading south, soon 

 disappears in that direction. Although the number re- 

 mains about the same for two weeks, we soon lind that 

 a change has been going on from the l)eginning. As early 

 as September 1 we become aware that we have almost 

 entirelv to do with birds of the vear. The old birds, the 

 old males, at least, have mostly left. 



The most imposing sight may be had by disturbing the 

 aiTny at the moment when all have settled on the sand. 

 The whole mass goes up in a body, turning right and left, 

 forms two mighty streams which unite above the water 

 in a great whirl])ool, rushes up and down, sweeping 

 along the river to a distant point, then coming back again 

 like a huge cloud, which moves hither and thither until 



