Til A LASSEUS POLIOCERCUS (Gould), 



BASS'S STRAITS TERN. Genus: Thalasseus. 



rflHE English tvpe of this species is tin- Kentish Tern, and in general habits it resembles that 

 I variety i it i-. however, a rather larger bird. 



During the winter months this Tern is very abundant on the shores of New South Wales 

 and Victoria, and vasl flocks frequent the islands of Bass's Straits; in that season small flocks make 

 their waj in'" the various bays and inlets, and very often ascend far up the rivers and remain about 

 ill, gaild »»nd mud flats till the warm weather returns. Whilst in these localities their principal food 

 consists of the shoals of small tish — principally mullet — which are then very plentiful. 



These flocks vary in numbers from ten to a hundred, and each would seem to possess its 

 exclusive range of Ashing ground, although when an especially large shoal of fish appears on the surface, 

 tli, whole will combine forces for an onslaught, when nothing can exceed the address and suddennes 

 with which these birds dart upon and secure their prey, this species being one of the swiftest of 

 the Tern family. 



During the prevalence of heavy easterly gales on the coast of New South Wales, numbers of 

 these bird- will seek refuge inland, and alighting on the margins of swamps and marshes, even though 

 those place-, should be in close proximity to man. will there remain till tine weather sets in, when they 

 return to their usual haunts about the sea shore. 



High, inaccessible rocks, standing some distance from the shore, are usually chosen as breeding 

 places, and here the birds deposit their eggs in the crevices of the rock, generally on the side facing 

 the land and out of the reach of the spray should stormy weather happen. About the coast of New 

 South Wales many such rocks may be observed, covered with the white excrement of these Terds 

 and (lulls, the latter bird fishing and dwelling with perfect amity with the present species. 



The eggs aie usuallv of a dull cn-ev colour, although manv are seen of a liyht buff tinge: but 

 all present the same irregular blotches and streaks of brown : in many instances these markings bear a great 

 resemblance to Chinese characters, and in some the blotches are so thick at tin' larger end as to blend 

 and form a distinct zone. 



There is no outward difference in the sexes; in summer the mottled black and white heads 

 o| the adtdt birds change to the deepest jet black. 



Crown of the head and occipital crest, deep black; forehead, sides and back of the neck and all 

 the under surface, silky-grey ; back, wings and tail, ashy-grey ; bill, bright yellow ; legs and feet, brownish 

 black. 



Total length, 17^ inches; bill, 2| inches: wing, I2§ inches; tail, 7 inches: tarsi, 1 inch. 

 Habitat-. : The coasts of' New South Wales and Victoria and the islands of Bass's Straits. 



