OCTOBER. 163 



QUICK CHANGES IN HOUSE-MARTINS. 



Unless you chance to witness the actual arrival 

 of a company of excited or wearied travellers, it is 

 not easy to keep an accurate " visitors' list " of those 

 birds which scatter themselves over the fields. While 

 some pass on inland, others of the same kinds take 

 their places unnoticed. Only our house-martins can 

 be registered exactly, because at this point of obser- 

 vation a single group of farm-buildings happens to be 

 the only suitable resting-place, with empty mud nests 

 under the eaves for them to sleep in, on four miles of 

 coast. So when, on the 6th, with the wind blowing 

 from the north-east, many more martins thronged to 

 the nests than had been seen since the 3rd, it was 

 plain that they were travellers from oversea. On the 

 next day they all departed, leaving only the two 

 pairs which still had young in their nests. The same 

 thing had happened on the 3rd, when the flock which 

 had arrived on the previous day departed. On the 

 8th, however, the barn roof was crowded again. Thus 

 during a week of east winds the population of house- 

 martins had been changed three times, only two pairs 

 which still had young remaining, as each flock of 

 travellers came and went in turn. 



How BIRDS TRAVEL. 



October 16. The ordinary route of our travelling 

 birds in autumn is from nor'-nor'-east to sou'-sou'- 

 west, because it is the cold north or north-east wind 

 which makes them move, and the natural trend of 

 the land in this part of Europe is to the south and 



