166 BIRDS OF TASMANIA. 



with ashy-grey; irides brown (practically invisible at night time); 

 bill black; legs and feet, outer edges black, inner and webs much 

 paler. Dimensions in mm.: Length, 410; bill, 34; wing, 280; 

 tail, 82; tarsus, 49. 



Female. Plumage similar; dimensions vary but little. 



Nest. An obliquely driven burrow, ranging in length from 1 to 

 7 feet, largely depending on the nature of the soil. The burrows 

 are so close together on some rookeries as to honeycomb the ground. 



Eggs. Clutch one; shape varies from oval to slightly elongated 

 oval ; texture fairly coarse ; surface minutely pitted and faintly 

 glossy; colour pure white at first, but usually soon becoming nest- 

 stained. 'Dimensions in mm. of examples from different rookeries: 

 (a) 73 x 47, (b) 80 x 58, (c) 72 x 44, (d) 75 x 57. Should the 

 burrows be robbed at the beginning of the season another egg is laid. 



Breeding Season. Birds arrive to scratch out their burrows 

 about the 20th September ; eggs laid about 25th November, varying 

 only a day or two each year. Young birds are able to fly end of 

 April or beginning of May. 



Geographical Distribution. Seas of Tasmania, Australia, and 

 New Zealand; also northward to Japan and eastward to Samoa. 



Observations. So much has been written about this interesting 

 Petrel that I shall make my notes as brief as possible. 



Only those who have witnessed a flight of Mutton-Birds can 

 have any conception of the vast numbers in which they move. On 

 two occasions I have been fortunate enough to witness gigantic 

 fights during the daytime. The second and more remarkable 

 occasion was on the 2nd October, 1909, when, standing on the top 

 of an island off the north coast of Tasmania, I watched a stream 

 of birds go by that lasted all the morning, and must have numbered 

 hundreds of thousands. One of the earliest accounts of the vast 

 hordes of birds to be seen during certain seasons in Bass Strait is 

 by Flinders, who, accompanied by Ross, was, in December, 1798, 

 in the neighbourhood of Three Hummock Island. According to 

 calculations made by him, the birds numbered some 132,000,000. 

 Since that time many more or less full accounts have appeared in 

 various publications concerning the vast numbers seen in Bass 

 Strait and vicinity. 



When on Ninth Island in September, 1909, I had the good 

 fortune to witness the incoming of a flight of birds for the purpose 

 of cleaning out their burrows in preparation for the laying season, 

 which commences on or about the 25th November every year. 

 The first bird of the season put in an appearance at 6.30 p.m. on 

 the evening of the 29th. It was observed that the birds did not at 

 once enter their burrows on alighting, but rested on the ground 

 outside for some time as though worn out. The mouths and 

 throats of a couple of individuals secured for taxidermical purposes 

 were full of a pasty substance of the appearance and smell of semi- 

 masticated tinned salmon. It is generally thought that the food 



