TREE-MARTIN 29 



or tree ; and if it be still occupied by the rightful 

 owners, after much time has been spent in sporting 

 about and reconnoitring it, a feud begins which 

 is often exceedingly violent and protracted for 

 many days* 



In seasons favourable to them the Oven-birds build 

 in autumn and winter, and breed early in spring ; so 

 that their broods are out of their clay houses by the 

 end of October or earlier ; when this happens the 

 Swallow that breeds in November quietly takes 

 possession of the forsaken fortress. But accidents 

 will happen, even to the wonderful fabric of the 

 Oven-bird, It is sometimes destroyed and must be 

 rebuilt ; or its completion has perhaps been retarded 

 for months by drought, or by the poor condition of 

 the birds in severe weather ; or the first brood has 

 perhaps perished, destroyed by some tree-climbing 

 enemy ; a young opossum for instance, less than a 

 rat in size, and able to squeeze itself into the nest- 

 ing chamber. November, and even December, may 

 thus arrive before some pairs have hatched their 

 eggs ; and it is these unfortunate late breeders that 

 suffer the violence of the marauding Swallows. I 

 have often witnessed the wars of these birds with 

 the deepest interest ; and in many ovens that I have 

 opened after the builders had been expelled I have 

 found the eggs of the Oven-bird buried under the 

 nest of the Swallows. After the Swallows have taken 

 up a position near the coveted oven, they occasionally 

 fly towards and hover about it, returning again to 

 their stand. By-and-by, instead of returning as at 



