ZOOLOGICAL SOCIETY BULLETIN 



1015 



out the boundaries of the Zoological Park, 

 where they could perform undisturbed their 

 domestic duties. In consequence, their num- 

 bers were becoming much reduced, but since 

 the establishment of the Park, a few birds 

 have spent the summers with us, nesting in 

 the tall trees behind the Beaver Pond, and 

 taking toll from the small fishes with which it 

 abounds. 



Late in 1910, we gladly accepted an offer of 

 as many night herons as we cared to have, 

 from the colony in the National Zoological 

 Park at Washington. On February 11, 1011, 

 ten birds reached us — all fully adult and in 

 perfect plumage. They were kept in the 

 Aquatic Bird House until the first of May. 

 and then were liberated on one of the islands 

 in Lake Agassiz, the right primal ies of each 

 being clipped to prevent its flying. We found, 

 however, that if the birds were disturbed, 

 they did not hesitate to take to the water, in 

 which they swam with as much apparent ease 

 as any duck. It must have been more difficult 

 than it seemed, however, for after reaching 

 what they considered to be a safe distance from 

 the threatened danger, they rested quietly, 

 returning to the island as soon as their fears 

 were allayed. 



The birds were fed daily and soon became 

 quite tame. They did not breed, however, 

 and when they acquired full wings at the 

 autumnal moult, we anticipated the end of 

 our heron colony. But much to our surprise 

 they made no attempt to leave the lake and 

 were always to be found perched upon the 

 trees along the shore. Their daily feeding 

 was continued and as cold weather approached 

 they were joined by a great number of others, 

 mostly immature, which doubtless were at- 

 tracted by the plentiful food, so easily ob- 

 tained. These birds remained throughout the 

 winter, twenty-four being the largest number 

 seen at one time. 



With the coming of spring, most of the 

 herons departed to other breeding grounds. 

 Those that remained became very tame, fre- 

 quenting the enclosures of gulls and storks 

 hoping to filch stray bits from the food pans. 

 Although no nests were observed, it seems 

 most probable that some of these birds bred. 



In the fall of 1912, out-lying herons returned 

 in even greater numbers, over forty appearing 

 each afternoon to share the chopped fish 

 prepared for them. Of this number, no doubt 

 some, at least, will remain to nest on Lake 

 Agassiz this summer, so the permanency of 

 our heron colony seems assured. L. S. C. 



MALFORMED ANTLERS 



OF the many curiosities of animal life — 

 if it may be so termed — none is more 

 interesting than the development of 

 the antlers of male deer. To the majority 

 it is a myth, and deservedly so, since the casual 

 visitor to any park or garden has only frag- 

 mentary opportunities of observing this mush- 

 room-like change. He may see the animal 

 without antlers; perhaps in the first stages of 

 the growth, or in the last stages when the 

 antlers are great, thick, brown clubs like the 

 hairy stalks of a sprouting fern, or, fully 

 grown, with the velvet hanging in strips from 

 the hard, white, bony structure. His interest 

 in the matter ceases there, or he may suspect 

 that it is the proper time for the animal to 

 have his antlers, without burdening his mind 

 over a problem in which he has no immediate 

 concern. It is not our purpose, however, to 

 demonstrate to the readers of the Bulletin 

 a fact with which they are probably all con- 

 versant, but to illustrate pictorially a peculiar 

 phase of development that sometimes occurs 

 during the process of antler growth. 



Rarely, if ever, are both beams of any 

 antlers equal in size; but they are sufficiently 

 so to present a pleasing effect of symmetry. 

 A striking exception is the caribou, which 

 nearly always has a palmated brow tine on 

 one beam. As this formation is practically 

 the same with all specimens of many species of 

 the caribou, it cannot be termed malformed, 

 but rather a highly specialized growth 

 through evolutionary processes. 



Even more interesting perhaps than the 

 normal development is the freakishness of the 

 growth at times. One season the animal will 

 have graceful and symmetrical antlers, and 

 the next, one beam will be so distorted as to 

 bear more the appearance of a battered branch 

 of a tree than the antler of a deer. 



The reason for the first year's deformity is 

 not perplexing. Usually it is due to an injury 

 received in the first stages, just as the antler 

 is commencing to round out over the skull. 

 As the males are exceedingly timid at that 

 period, they will plunge blindly in any direc- 

 tion under the stress of their highly keyed 

 nervous organism, and if the antler is bruised 

 by chance, the abnormal development will 

 manifest itself in the course of a week. A 

 slight injury will not always change the form 

 of the antler, but if the injury is received after 

 the antler has grown eight or ten inches, it usu- 

 ally retards the growth so that the fully mat- 

 ured antlers are very perceptibly different 



