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8 REPORT — 1901. 



Some Notes on the Behaviour of Young Gulls artificially hatched. 

 By Professor J. Arthur Thomson, M.A. 



[Ordered by the General Committee to be printed in extensoJ] 



The biological and psychological interest of the observations made by 

 Professor C. Lloyd Morgan and others on the behaviour of artificially 

 hatched young birds (especially chicks) led me this summer to utilise an 

 opportunity which presented itself of incubating some eggs of Larus 

 ridibvAidus and of observing the behaviour of tlie young. I had also 

 wished to obtain material for testing the influence of different kinds of 

 diet on the texture of the stomach, but this j^roblem was not followed 

 up. Although my observations are not in any way surprising, they raise 

 a number of interesting questions ; and it is, of course, well that we should 

 contrast the ways of a thoroughly wild bird with those of the chick, which 

 has probably been to some extent changed by domestication. 



Some of the gulls which I hatched in my laboratory were given to 

 Dr. Lewis Maclntyre, lecturer on comparative psychology in the 

 University of Aberdeen, and I am indebted to him for confirmation and 

 extension of certain facts which I noticed. But, as he has not seen this 

 communication, he is not in any way responsible for errors of inference 

 which may have crejst in. I should also notice that four newly hatched 

 birds from different nests were used for comparison with those that were 

 artificially incubated. 



Among observations made on repeated occasions at the guUery the 

 following may be noted, though they may be familiar to many. 

 Although the thousands of birds are extraordinarily quick to take 

 alarm — generally, to human perception, quite needlessly — they acquiesce 

 in two or three minutes to the presence of an intruder in a boat, if he sit 

 still under a covering of sacking. The birds will then come within 

 arm's length and settle down, though the shape of the observer who is 

 peering through holes cut in the sacking forms the most conspicuous 

 object in the immediate environment. By this method it was possible 

 to make sure of the fact that the same bird comes back to the same nest. 

 As there may be hundreds of nests within a small radius — at least half-a- 

 dozen on the area of an ordinary household dining table — and as the very 

 uniform bank of mud, tussocks, and bog-bean stems presents to our eyes 

 few distinctive marks, and as there is continuous rising, squabbling, and 

 resettling, it seemed well to take some pains to fix attention on birds 

 with some slight peculiarity of plumage, and to prove that they came 

 back to their proper nest. The extraordinary variability of the colora- 

 tion of the eggs — from unspotted pale blue to very dark brown with 

 darker spots — may facilitate the recognition of the nest during the day. 

 On one occasion I observed that a very young nestling of the first or second 

 day which had tumbled out of its own nest and crawled to the next one 

 was accepted without demur. Older youngsters, able to run about, are 

 pecked at very viciously when they come near a brooding bird. 



First Day. — Observations in regard to behaviour immediately after 

 artificial hatching were greatly hindered by the fact that the young birds 

 are so imperfectly warm-blooded. Something of the nature of a hothouse 

 would be useful. When the young creatures were taken from the incubator 

 or from a warmed box they were in a few minutes oppressed with cold, 

 and uttered their cry of discomfort almost continuously. As observations 

 under conditions of discomfort did not seem of value, the birds were at 

 first studied only for a few minutes at a time. 



