RAPTORES. 63 



of its genus by its great size and powerful form. Probably 

 few of the Raptorial birds, with the exception of the Eagles, 

 are more formidable or more sanguinary in disposition. 



Forests of large but thinly scattered trees, skirting plains 

 and open districts, constitute its natural habitat. Strictly 

 nocturnal in its habits, as night approaches it sallies forth 

 from the hollows of the large gum-trees, and flaps slowly and 

 noiselessly over the plains and swamps in search of its prey, 

 which consists of rats and small quadrupeds generally. 



I regret that the brevity of my stay in Tasmania did not 

 admit of sufficient opportunities for observing this bird in its 

 native haunts, and of my making myself acquainted with the 

 various changes which take place in the colouring of its plu- 

 mage. Considerable variety in this respect occurred among the 

 specimens I collected — not so much in the form of the markings, 

 as in the hue which pervades the face, neck, under surface, and 

 thighs. In some these were deep rusty yellow ; in others the 

 same parts were slightly washed with buff, while others, again, 

 had the face of a dark reddish buff approaching to chestnut, and 

 the under surface much lighter ; I have also seen others with 

 the facial feathers lighter than those of the body, and, lastly, 

 some with the face and all the under surface pure white, with 

 the exception of the black spots which are to be found in all. 

 Whether the white or the tawny plumage is the characteristic 

 of the adult, or whether these changes are influenced by 

 season, are points that might be easily cleared up by persons 

 resident in Tasmania ; and I would invite those who may be 

 favoiu-ably situated for observation to fully investigate the 

 subject, and make known the results. 



The sexes differ very considerably in size, the female being 

 by far the larger, and in every way more powerful than the 

 male. 



Facial disk deep chestnut, becoming deeper at the margin, 

 and encircled with black ; upper surface, wings, and tail fine 

 rufous brown, each feather irregularly and broadly barred 



