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ZOOLOGICAL SOCIETY BULLETIN. 



NEW ZKBRA AND WILD HORSE HOUSES, AND THEIR ENVIRONS 



ZOOLOGICAL PARK NOTES. 



New Rodents. — Our collection of western rodents 

 lias materially strengthened the small mammals 

 grouped in the economic rodent-reptile series. These 

 consist of gopher rats, pack rats and several of the 

 smaller species of rats and mice that injure the 

 products cf the great grain belts. While it has 

 been alleged that the average life of small mammals 

 is comparatively short, this being particularly the 

 ease with the rodents, we have already made some 

 interesting notes relating to the longevity of species 

 of North American gnawing animals. The jumping 

 rat (Dipodomys) lived in this collection for a period 

 of three years. 



Sagacity of Monkeys. — It amuses our visitors to 

 watch the monkeys operate the swinging doors that 

 lead to their outside cages. These doors are hinged 

 from above, and swing both ways. The object is 



to enable the hardy monkeys to run out of doors 

 at will, and at the same time prevent drafts from 

 entering the cages. Some of the monkeys appear to 

 take a vindictive delight in enticing a cage-mate to 

 one of the doors, holding it open for an instant, 

 then suddenly darting through and allowing the door 

 to come down with a bang upon the head of the 

 follower. It is quite surprising to observe how read- 

 ily the new arrivals learn to operate these doors. 

 Usually this is accomplished within a half hour after 

 specimens have been installed. The common macaque, 

 the rhesus monkey, the mangabeys and black apes 

 run out in the coldest weather, and appear to enjoy 

 a wild romp in a temperature well below freezing. 

 After a half hour's play they will enter the build- 

 ing, and after becoming well warmed, are ready to 

 sally forth again for another limited period. 



Signs of Winter. — Already we have experienced 

 temperatures well below 20 degrees Fahrenheit; and 



