CARE OF CAPTIVE ANEVIALS — WALKER 333 



animals regularly become entangled, with the result that they strain 

 or injure themselves. Others appear to learn quickly how to avoid 

 such troubles. 



When animals are so restrained, it is particularly important that 

 the chain be short enough so that it cannot become entangled with 

 such objects as pegs in the ground, limbs in trees, crossarms on posts, 

 or other obstructions. 



If careful attention is given to choosing species that will not harm 

 each other, and sufficient space and suitable conditions are provided, 

 very attractive and interesting groups can be maintained. For 

 example, in a large cage or outdoor enclosure with pools or other 

 natural features, several different species of birds (see pi. 4, fig. 1), 

 reptiles, and mammals can be exhibited if properly selected. Large 

 cages with many individuals of a single species afford considerable 

 activity; and if belligerent individuals are eliminated, such groups 

 frequently do well and multiply, if provided with the proper facilities 

 for nesting or rearing young. 



Heed should always be given to placing cages, aquaria, or chained 

 animals where conditions can be comfortable regardless of the weather 

 and without too much dependence on the thoughtfulness of caretakers. 



Modern steel alloys, particularly the so-called stainless steel of the 18 

 and 8 group, are exceptionally good material for cage construction, as 

 they are very strong and do not corrode under contact with excretions 

 and secretions of the animals. The dull finishes are preferable, as they 

 are less conspicuous to the eye. Electric welding is particularly desir- 

 able in the construction of such cages, as it provides a maximum of 

 strength with a minimum bulk of material. The aluminum alloys 

 should be avoided, as all that have come to my attention when used for 

 making cages have been subject to very rapid corrosion from the ex- 

 cretions and secretions of the animals. Wlien in contact with steel, 

 this action is still further accelerated. 



In regard to all cage and paddock construction there should con- 

 stantly be borne in mind the fact that there must be no sharp projec- 

 tions about the cage on which animals can hurt themselves. Ends of 

 wires should be carefully bent or otherwise guarded to prevent animals 

 from injuring themselves or leaving tufts of hair or fur on them. If 

 there is to be more than one animal in an enclosure, it is well to avoid 

 having any of the walls come together at angles less than 90°. Angles 

 of about 135° are to be preferred as they will provide no narrow cor- 

 ners into which one animal can drive another and harm it. The same 

 idea should be borne in mind in constructing shelter houses for the 

 larger hoofed animals. 



Practically every enclosure should have some kind of a shelter or 

 nest box. Houses may be built in the corner of the yards for large 



