828 



ZOOLOGICAL SOCIETY BULLETIN 



POTO. 



OUR SERIES OF RARE MAMMALS. 



By R. L. DlTMARS. 



Curator Reptiles; Asst. Curator Mammals. 



AMONG those interested in the maintenance 

 of a zoological collection, and on the look- 

 out for new and interesting specimens, there 

 is a designation for certain creatures infrequent- 

 ly received as "rare" exhibits. This so-called 

 rarity may be brought about by two causes, 

 namely, the difficulty of capture of representa- 

 tives of some species, or the inability of an ani- 

 mal to survive a long voyage, or endure long 

 confinement under cage conditions. It is the 

 so-called delicacy of many species that has ren- 

 dered them so rare on public exhibition. With 

 the period of construction in the Zoological Park 

 now almost completed, we find more time to 

 studv tile ways and wants of the delicate species. 



During the past five years, we have been en- 

 deavoring to maintain a number of species of 

 small mammals not often found on exhibition. 

 In this short resume a few of our results are 

 cited. The points relating to the cage, tem- 

 perature and food of nearly allied animals are 

 the primary factors to consider. 



Of course a proper amount of light is an es- 

 sential. With some species the right amount 

 of light means but little of it ; while others crave 

 the sun, and without it are as sluggish as man}^ 

 reptiles. Exercise is absolutely essential, and 

 with some species it is impossible to produce this 

 without nervous stimulation. 



While the question of temperature is impor- 

 tant, it is of interest to note that even the trop- 

 ical species do better in moderate heat than in 

 an overheated temperature. None of our ex- 

 perimental animals are coddled within stuffy, 

 poorly-ventilated cages, as has been a common 

 practice with such creatures. We know that 

 pure air is one of the requisites. Feeding is the 

 next most important factor ; and it is not only 



the question of the character of the food, but 

 how to present it to the animal, that must be 

 considered. Many animals are ravenous in appe- 

 tite, and the common result among such is gas- 

 tritis. This conies not entirely from the type 

 of food used, but partly from permitting the 

 animal to gorge itself, with the consequence of 

 being unable to assimilate the entire contents of 

 the stomach. On the other hand, some speci- 

 mens will starve, unless coaxed and teased to 

 eat, — a jirocess that may necessarily require 

 repetition a half-dozen times the day, with a 

 variety of the foods that are most tempting. 



From past experiences, and consultation 

 among our colleagues, we have divided those 

 types of mammals that are extremely short- 

 lived in captivity, into several groups. One of 

 these includes species that succumb to gastro- 

 enteric troubles, others that are sluggish, and 

 another group of excessively nervous types. 



The members of the two latter groups are 

 poor feeders. Often they die from malnutri- 

 tion, when the internal organs show few traces 

 of actual disease. Witli a keeper of sympa- 

 thetic interest in charge of a miscellaneous col- 

 lection of delicate mammals, it is a question of 

 constant experimenting until the needs and 

 ways of the dumb charges are elicited, one after 

 another. At times the requisite points of suc- 

 cessful treatment is discovered by accident. 

 This was illustrated to the writer in the case 

 of the Egyptian jerboa, a remarkable, kanga- 

 roo-like rat. 



While in London he purchased two lots. of 

 these interesting creatures, one of which was in- 

 tended for exhibition in the Zoological Park, the 

 other to be employed as exhibits in the writer's 

 lectures among the public schools. The former 

 lot was placed in the Reptile House, and provid- 

 ed with the standard sleeping house. The writer 

 noted that all the specimens would pack into 

 their nests during the day, and when examined 



RED HOWLER MONKEY. 



