92 Transactions. — Zoology. 



Art. XV. — Observations on Cook's Petrel (Grey), Procellana 



cooki (Ti Ti), their Habits and Habitats. 



By A. Eeischek, F.L.S. 



[Read before the Auckland Institute, 24 August, 1885.] 



This pretty little Petrel is not so common as the previous 

 species, according to Dr. Buller, F.K.S., etc. ; there have heen 

 only a few specimens obtained, and very little is known of 

 their habits, but I have succeeded in observing them care- 

 fully. The first time I met with this bird was in December, 

 1880, on my second research at the Chickens or Morotiri 

 Islands, on the western slope of the larger island, along with the 

 Tuatara (Sphenodon punctatum), in one burrow. Professor von 

 Haast, F.R.S., etc., read a paper of mine before the Philoso- 

 phical Society, Christchurch, on the latter (see " Transactions, 

 N.Z. Institute," vol. xiv). On tbe north-eastern portion, near the 

 centre of the Little Barrier or Hauturu Island, in October, 1882, 

 my dog set a burrow ; and on digging into it, I was surprised at 

 finding a pair of these Petrels also on this island ; they came 

 ashore to clean out their burrows, which process is accom- 

 plished with their bill and feet, as I have already described in a 

 previous paper. I measured several of their burrows, and found 

 the average width at the entrance from 4 inches to 6 inches in 

 diameter, and from 4 to 8, and even 12, feet from the entrance 

 to the chamber, of which I always found two in each burrow, 

 and which were from 1 foot to 1± feet long, 1 foot deep, and 

 from 6 inches to 1 foot high ; in each chamber is a hollow filled 

 with leaves, moss, or fine grass. I found these burrows even in 

 the stiffest clay, winding about roots and stones. I often worked 

 half a day, and then had to give it up without success. Male 

 and female mutually assist at cleaning out or making fresh 

 burrows. After sunset they begin to call like " ti, ti, ti," repeated 

 rapidly, which is the signal to assemble for their departure to 

 their ocean hamits, from which they do not return till before 

 sunrise ; this process goes on nightly till their burrows are 

 cleaned out and the nest made. I built a hut in the centre 

 of the Little Barrier, near one of these burrows, on purpose 

 to make a closer observation of these rare birds. The 1st 

 November, when they returned as usual, early in the morning, 

 I noticed that they made a peculiar noise in their burrows ; 

 in about half-an-hour one came out and stopped for a moment, 

 then flew away, and did not return till after sunset, when he 

 flew several times round above the burrow, and then went off 

 again, not returning till next night, when he went into the 

 burrow and made the same gurgling noise as before; after a 

 while a bird came out and flew away, which returned before 



