ZOOLOGICAL SOCIETY 

 BULLETIN 



Published hy the New York Zoological Society 



Vol XIX. 



JANUARY, 1916 



Number 1 



THE RODENT COLLECTION IN THE REPTILE HOUSE 



By Raymond L. Ditmars. 



ABOUT eight years ago, while the writer 

 was making a tour of the zoological parks 

 and gardens in the United States he noted 

 in one of these collections an attempt to exhibit 

 a series of the smaller rodents. The animals were 

 in glass eases, and provided with sleeping boxes 

 or bunches of cotton wool. In not a cage was a 

 specimen visible and the only indication of the 

 species represented was in the explanatory mat- 

 ter on the labels. 



Two years later, while on a similar trip 

 among the zoological collections of Europe, sev- 

 eral series of rodents of like arrangement were 

 noted. The advice elicited was to the effect that 

 while the smaller rodents were of interest from 

 their markedly varied form and coloration, the 

 practicability of using up space in an endeavor 

 to exhibit them was very doubtful. This con- 

 dition resulted from the following difficulties : 

 1. The nocturnal habits of the greater number 

 of species, resulting in persistent hiding in the 

 nests during the day. 2. The short lives of 

 most of the species, owing to improper environ- 

 ment and lack of exercise. 3. The difficulty 

 of obtaining new specimens. This latter con- 

 dition was due to a general lack of interest 

 among animal dealers in the very small mam- 

 malia. 



After these preliminary observations of other 

 attemjjts to exhibit the smaller rodentia, the 

 writer determined upon a series of experiments 

 in the New York Zoological Park, for the pur- 

 pose of successfully exhibiting a varied series of 

 the gnawing animals, but in such a way that 

 the specimens could be seen, and at the same 

 time kept in good health, and enabled to live a 

 reasonable length of time. 



The first series of animals for our experiment 

 consisted of several species of spermophiles, 

 kangaroo rats and miscellaneous mice. Thus 

 the experimental group embraced both nocturn- 

 al and diurnal species. 



As it was realized that the nocturnal species 

 would retire within sleeping boxes during the 

 day, their shelter was in the nature of a scant 

 handful of hay. It was believed that without 

 some kind of a shelter from observation, they 

 would be excessively nervous and soon would 

 die. The cages of the diurnal species were pro- 

 vided with about six inches of packed earth, 

 to provide them exercise in burrowing. The 

 cages were of a type commonly known as "ter- 

 raria," with four glass sides, the glass sliding 

 in grooves. Each case was provided with a top 

 of fine wire netting or screening. 



Our early experiments with these cages taught 

 us many things. The nocturnal rodents so skill- 

 fully collected their hay in corners that when 

 they crouched motionless beneath the nesting 

 material their bodies could barely be seen. 

 With the diurnal species there was an immediate 

 tendency to dig burrows in the earth, and re- 

 main under cover the greater part of the day. 

 The four glass sides and mesh tops of the cases 

 were found to be a poor arrangement for proper 

 ventilation. Moreover, it was difficult to clean 

 the inside of the glass. When the cover was 

 slid to one side, even though ever so carefully, 

 the more nervous specimens were liable to leap 

 up to the sides and escape. 



It was by frequent changes of this experi- 

 mental series of cages that we evolved a satis- 

 factory and valuable exhibit of rodents. We 

 now have a large series of cages, about fiftv in 



