144 BIRDS OF AUSTRALIA. 



The extent of its range northward has not yet been satisfac- 

 torily ascertained, beyond the certainty that it has not hitherto 

 been received in any collection from the north coast. 



It may be regarded as strictly migratory in Tasmania, where 

 it arrives in October, and after rearing at least two broods 

 departs again in a northern direction. On the continent of 

 Australia it arrives rather earlier, and departs later ; but a 

 scattered few remain throughout the year in all the localities 

 favourable to their habits, the number being regulated by the 

 supply of insect food necessary for their subsistence. I may 

 here observe, that specimens from Swan River, South Australia, . 

 and New South Wales present no difference either in size or 

 colouring, while those from Tasmania are invariably larger in 

 all their admeasurements, and are also of a deeper colour. 



This Wood Swallow must, I think, ever be a general favourite 

 with the Australians, not only from its singular and pleasing 

 actions, but from its often taking up its abode and incubating 

 near the houses, particularly such as are surrounded by pad- 

 docks and open pasture-lands skirted by large trees. It was 

 in such situations in Tasmania that, at the commencement of 

 spring, I first had an opportunity of observing this species ; 

 it was then very numerous on all the cleared estates on the 

 north side of the Derwent, about eight or ten being seen on a 

 single tree, and half as many crowding one against another 

 on the same dead branch, but never in such numbers as to 

 deserve the appellation of flocks : each bird appeared to act in- 

 dependently of the other ; each, as the desire for food prompted 

 it, sallying forth from the branch to capture a passing insect, 

 or to soar round the tree and return again to the same spot ; 

 on alighting it repeatedly throws up one of its wings, and 

 obliquely spreads its tail. At other times a few were seen 

 perched on the fence surrounding the paddocks, on which 

 they frequently descended, like Starlings, in search of coleo- 

 ptera and other insects. The form of the wing of the Artamus 

 sordidus at once indicates that the air is its peculiar province : 



