40 



JOURNAL OF MAINE ORNITHOLOGICAL SOCIETY. 



of June, so the period of incubation 

 must be between two and a half and 

 three weeks. The first young are usu- 

 ally on the wing by the last of July. 



The normal number of eggs in a set 

 is usually three, and nine-tenths of the 

 sets belonging to the first laying contain 

 this number. When the nests have 

 been robbed the second set laid com- 

 monly contains only two eggs, and while 

 the eggs of a set are usually very simi- 

 lar in size, color and markings, yet in 

 many cases they are very different. I 

 have seen about fourteen sets of four 

 eggs each, eight sets of five each, four 

 four of six each and one set of seven 

 eggs, during my visits to these islands. 



Most of the sets of four eggs had 

 the eggs of each set very similar to one 

 another, and many of the sets of five 

 also seemed to be the product of one bird 

 in each case. One set of six eggs seem- 

 ingly must have been laid by one bird as 

 the eggs were almost exactly alike in 

 size, color and markings, while the re- 

 maining sets of six contained eggs of 

 two different types, three eggs of each 

 type. The set of seven contained four 

 of one type and three of another. A 

 set of six eggs measure as follows : — 

 1.65x1.20, 1.65x1.22, 1.65x1.21, 

 1.53x1.20, 1.64x1.21, 1.58 x 1.20. 

 This set was taken on Trumpet Island, 

 June 2;jrd, 1897. 



The ground color of the eggs varies 

 quite as much as in the case of the 

 Herring Gull of whose eggs those of the 

 Terns are almost exact miniatures. 

 The prevailing ground color se( ms to be 

 a cinnamon or greenish brown, though 

 in some eggs it is of a light bluish-white 

 color. The markings, which are some- 

 what more abundant about the larger 

 end, are brown, black, umber, lilac, 

 slate, etc. 



The Terns live almost entirely on 

 small fish which they catch with great 

 dexterity, and a vast concourse of these 

 birds may often be seen hovering and 

 shrieking over a school of fish, and con- 

 stantly plunging down and emerging 

 from the water with their prey. The 

 fishermen call them Mackerel Gulls. 



These birds make noises most of 

 which are variations of their favorite 

 cry, a harsh, grating "chir-r-r." When 

 their breeding grounds are approached 

 they rise and circle high overhead uttei- 

 ing this note. They usually keep well 

 out of gunshot, but if one of their num- 

 ber is killed or wounded the remainder 

 will descend and hover for some time 

 over the body giving the hunter a chance 

 to secure many more victims. 



They seem to arrive early in May, 

 and many depart southward by the last 

 of August thougji some remain well into 

 September. Their numbers are de- 

 creasing gradually, but as now they are 

 fully protected by law, their ultimate ex- 

 tinction will not take place for some time 

 to come. All Terns are good swimmers. 



Arctic Tern. Sterna paradisa a Hriinn. 



The only place where I have met this 

 species is in the vicinity of Ship, Barge 

 and Trumpet Islands, closely associated 

 with the foregoing species, and do not 

 think that over fifty pair of these birds 

 nest on all these islands. Although I 

 have looked for tliem on other islands 

 where the Terns nest I have failed to 

 find them. 



The eggs are not distinguishable from 

 those of the preceding and the habits of 

 the birds are identical. The Arctic 

 Terns seem to prefer to place their eggs 

 in a hollow in the sand at the edge of 

 the grass, and I think this is a character- 

 istic of the species. 



(To be continued.) 



