88 
LEWIS, Mutton-Birds of Phillip Island [ T ist o™" 
apparently a rabbit warren, one entrance to which was in the 
middle of the path. This hole was filled in with sand and 
trampled hard. One evening a bird was noticed to run on to 
this patch of sand and walk around slowly, apparently looking 
for something. It passed several burrows, but made no attempt 
to enter. On returning to the sand patch it sat for a minute 
or two, and then went off again on a short tour of exploration. 
This procedure was repeated about five times. Finally the bird 
returned, and began to scratch on the site of the old burrow. 
The next morning the burrow was open and was occupied during 
the season by this bird and its mate. 
OBSERVATIONS ON THE QUESTION AS TO 
WHETHER THE MUTTON-BIRD LAYS AGAIN 
IF ITS EGG IS TAKEN. 
The opinion is held widely amongst the Mutton-bird “eggers” 
frequenting the rookeries on Phillip Island that when the Mutton- 
bird is robbed of its egg it lays again. This belief has its foun¬ 
dation in the fact that in working a certain portion of a rookery 
<<e gg ers ” S et f res h eggs every day, and they naturally assume 
that this is due to the fact that the birds lay again after being 
robbed. Careful investigation seems to point to the fact that 
while fresh eggs are certainly taken each day, they are not ob¬ 
tained from the same burrows, except on odd occasions. It is 
not every burrow that will yield an egg, but on most of the 
rookeries the burrows are packed so closely together that an 
“egger” working a comparatively small area every morning 
during the season will soon accumulate a fair number of eggs. 
Then again, the fact that such a large number of young birds 
reach maturity, although the burrows have been robbed every 
morning for a week during the egging season would seem to 
show that the birds lay again. The third ground for the belief 
that they lay again is the number of immature eggs found in 
a mature bird, but this seems to be a feature of all mature birds 
no matter of what species. To test the question as to whether 
the birds, if robbed, lay a second time in one season, sixteen 
burrows were selected and marked. In 1920 the eggs were taken 
from six burrows as they were laid, between November 23rd 
and December 3rd, and the birds were marked with rings on 
their legs. In only one burrow was a second egg found, and 
in this instance two strange birds were with the egg. 
In 1921 a similar procedure was followed and the burrows 
were kept under observation until January 16th, 1922. In one 
hole two strange birds and an egg were found. In another a 
strange bird and an egg were found on December 15th. A 
marked bird, No. 82, and a new egg were found on December 
21st, but the hole was deserted eight days later. This bird (No. 
82) had been robbed on November 29th, but it is possible that 
the egg found with it was laid by a strange bird, owing to the 
