CANADIANOTTER 103 



either fight or run. It is evident that the males should be kept separate 

 from the females except duruig the mating season, and it would almost 

 certainly be necessary to isolate the females before the young were 

 born and until they were well grown. 



"The number of young in a litter is usually given as two or three, 

 but there are also records indicating four or five, and it seems probable 

 that the smaller numbers are those of the first year of breediag. Data 

 are extremely meagre on this point; but a number of records of families 

 of five or six otters seen together in summer would indicate four or 

 five young, whUe the uniform number of five mammae of the females 

 would further indicate four as the normal number. 



"Whether females breed when a year old remains to be tested, 

 but it seems probable that they do. 



" The fact that otters do not breed in zoological parks, where kept 

 on exhibition and imder constant excitement and nervous strain, is 

 not surprising and probably does not mean that under more normal 

 conditions they would fail to reproduce at their usual rate. 



"A large spring or section of a small stream, preferably in 

 Location t^i® woods, should be selected for an otter yard. A pool at 

 least six feet deep and 20 or 30 feet across should be formed. 

 Steep banks down which the otter can slide into the water are an 

 advantage in furnishing exercise as are also a few old logs reaching into 

 the water. If the banks are firm and stony the otter wUl be less in- 

 clined to burrow, and clear, cold, rimning water tends to keep them 

 in good health. A series of yards along a suitable stream could be 

 separated economically into family enclosures with inexpensive partition 

 fences. A yard 50 feet square is ample for a family of otters if plenty 

 of food is provided. 



"SmaU houses, hollow logs, shallow caves or artificial burrows 

 should be provided for sleeping quarters where a cool, dark retreat csii 

 be had at any time. 



" Otter yards should be inclosed with a fence four feet high, 

 Fencing made of heavy woven wire of one-inch mesh and with a 16- 



rnch curved tin overhang on the inside. The fence should 

 be carried on iron uprights four feet apart, curved in at the top for 

 the tin overhang. These iron uprights should be set in a stone or con- 

 crete wall, laid one foot deep in the groxmd and carried across the stream 

 as dams above and below the otter pool. In place of the wall an addi- 

 tional foot of the woven wire can be bedded in the ground, but, as it 

 rusts out, it will have to be renewed every few years. In the National 

 Zoological Park a welded wire fence with rectangular mesh one inch 



