THE OOLOGIST 



111 



rocks wliich are not spread on so 

 thick. The Terns live on tlie rocky 

 end, and as you wander about upon 

 them you are glad you wore rubbers 

 for these boulders are hard to walk 

 on, being slippery and tilted every 

 way. No attempt is made to make a 

 nest and their eggs lie about on the 

 flat rocks anywhere and everywhere. 

 Some tossed about by the wind are 

 broken, others lie in crevices filled 

 with rain water, but the greater pan 

 are safe and will hatch. Two or three 

 eggs are in most sets of both species. 

 A set of four is rare and Dr. Dyar, the 

 keeper, pointed out a set of five of the 

 Common Tern to me once. The eggs 

 vary greatly in color and marking. 

 Many odd eggs may be found. 



When first you appear among them, 

 the birds are much annoyed and per- 

 sist in flying about directly over your 

 head, uttering their noisy repeated 

 chir-r-r-r and teat-r-r-r and this sound 

 will stick in your head a long time 

 after you have left. In a short time, 

 however, many of them quiet down 

 and return to their eggs. 



Formerly the Rock had but a single 

 light, but a few years ago another 

 was added. The Terns arrive about 

 May 15th, and in the night and the 

 keeper told me that the night they 

 came after the second light had been 

 installed, they seemed to know they 

 were at the right place for they kept 

 flying about over the Rock but didn't 

 know what to think of the new light 

 and refused to land for three days. 



A good sized colony of Leach's Pe- 

 trel breed there. They are seldom 

 seen about their breeding grounds in 

 the daytime so it is hard to estimate 

 the size of a colony. It is said that 

 one of a pair will feed out to sea all 

 day returning at dusk to relieve its 

 mate in the burrow. In the little soil 

 patches, which is of a very light tex- 

 ture, are the burrows in which they 



lay their single white egg. Dull white 

 as a rule but often eggs will be found 

 with a distinct wreath of fine red dots 

 about the large end. As all the soil 

 had been used here for the burrows 

 many were forced to dig in under the 

 smaller stones and by tipping over 

 these stones you will generally find a 

 Petrel and its single egg. The nest 

 seems to be at the best only a few 

 pieces of grass. 



Under the boulders on the highest 

 part of the Rock a colony of perhaps 

 forty pair of Black Guillemot breed; 

 Sea Pigeons they are called there. 

 The size of a colony may be fairly 

 well determined by the number of 

 birds noted sitting about on the rocks 

 and in the water nearby, for they will 

 all be males and each one will have 

 a maid tucked away under the rock^ 

 on the eggs. Unless you can crawl in 

 among these immense boulders you 

 cannot move them and very often the 

 eggs are placed where they cannot 

 even be seen. When eggs are fresh 

 there is very little to go by in look- 

 ing for them but as incubation ad- 

 vances the bird white washes the 

 rocks leading to them, making it easy 

 to follow the trail. Sometimes a few 

 broken mussel shells, but more often 

 the one or two eggs lie on the bare 

 rock. Occasionally an egg will be 

 noted that appears from its position 

 to have been pushed to one side and 

 will be found to have either a crack 

 or dent in it. The bird probably 

 knows such an egg will not hatch and 

 pushes it away. The eggs are very 

 pretty and vary in size considerably. 



A few pair of Puffins formerly came 

 to the Rock to breed but several years 

 ago when I was there last Mr. Dyar 

 said they remained about for a while 

 that spring but felt sure they went 

 up the coast to breed. 



As these l)irds and their eggs are 

 well known to all, I submit these notes 



