MAMMALS 



otters to IO miles of stream.' In the Upper 

 Thames I should be inclined to say that there 

 must be fully one otter to every 5 miles of 

 river, which is a somewhat higher estimate 

 than that for the north of the county. A 

 curious fact about otters, which seems only to 

 have been realized of late years, is that they 

 breed at any time of year, although they do 

 not have more than one litter in about a twelve- 

 month. Certain animals, such as some of 

 the rodents, breed nearly all the year round 

 under favourable conditions ; and the gray- 

 seal breeds exclusively in the autumn, which 

 appears also to be the custom of the dor- 

 mouse, though rather earlier, and with greater 

 range of date ; while for a wild animal 

 only reproducing about once in twelve months, 

 to have no special season, appears to be 

 a unique arrangement. The female otter 

 comes in season with the greatest regularity 

 every month from the time she is ten months 

 old. The most common number of young 

 in my own experience is two, but frequently 

 three, a larger number being exceptional ; but 

 Mr. Uthwatt says, ' Three is about the usual 

 number of the litter, though they often have 

 four or five, and occasionally six.' 



My friend Mr. Thomas Southwell, 

 M.B.O.U., F.Z.S., was the first really to 

 grasp the fact that otters have young at any 

 time of year, and published notes on it in the 

 Zoologist for 1877 (p. i 72) and 1888 (p. 248) ; 

 the first of these being a reply to a note of 

 mine in the same volume (p. 100). It may 

 now be asserted with some confidence that 

 while the young are born during any month 

 of the year, yet that more litters are born 

 between October and February, both inclu- 

 sive, than during the remaining seven months 

 of the year. Mr. Uthwatt says on this point : 

 ' They breed all the year round, but probably 

 more cubs are born in January, February, 

 and March, than at any other time.' Though 

 differing most reluctantly from one with so 

 great a practical experience, I believe this is 

 not the case. 



I have noticed by observation of otters in 

 captivity, that the females when in season 

 have a curious habit, which seems to be 

 designed to attract the attention of any pass- 

 ing male. This is that they collect little 

 mouthfuls of short straws and deposit them 

 here and there. In a state of liberty short 

 bents or dead aquatic plants would doubtless 

 be substituted for the straws ; but outside a 

 cage these little tufts would be very difficult 

 for a human eye to recognize. Having once 

 noticed this habit among my otters in cap- 

 tivity, it is now easy to tell when one is in 

 season, without further observation. I began 



keeping otters in captivity in 1869, and during 

 the last thirty years have, with one short in- 

 terval of a few months, kept them continu- 

 ously, seldom having fewer than two in my 

 possession at any one time, and sometimes a 

 larger number. 



The story of the breeding of a litter in my 

 collection was told originally in a note pub- 

 lished in the Proceedings of the Zoological 

 Society, 1 88 1, p. 249 ; repeated with additions 

 in the Zoologist, 1882 (p. 20 1) ; and also copied 

 into the Live Stock 'Journal in the former year. 

 The facts noted are briefly as follows : Pair- 

 ing took place while swimming in the tank 

 early on 12 August, and after a gestation of 

 sixty-one days (during the last ten or twelve 

 of which the female was obviously gravid) 

 young were born on the afternoon of 12 

 October. The mother had been hand-reared 

 with a feeding-bottle, and was extremely 

 tame, so I ventured to look at the cubs on the 

 25th (when thirteen days old), finding them 

 to be two in number and about 8 inches in 

 total length. Though the mother made not 

 the smallest objection to my looking at the 

 cubs, yet on returning to them her instinct 

 came in, and within a couple of hours she 

 transferred them to the other bed-box. From 

 that day they were constantly (often daily) 

 shifted backwards and forwards from one box 

 to the other. They were in every case I 

 think removed by the most direct route 

 across the tank ; and the greater part of the 

 way they were under water, being carried by 

 the scruff of the neck. They were blind for 

 about thirty days. On 9 December, when 

 they were eight weeks two days old, they 

 first voluntarily emerged from the shelter of 

 the bed-box and made a little tour of inspec- 

 tion of the cage (about 28 feet long) ; they 

 went into the water both intentionally and 

 accidentally as was supposed. One had hung 

 half out of the box four days previously. 

 The next day I first saw the mother carry 

 fish into the box, to try to tempt the cubs to 

 begin a more solid diet ; and on the afternoon 

 of the same day the cubs were anxious to 

 take a little walk, but the mother hearing the 

 garden men grubbing some bushes, in spite of 

 her extreme lameness, felt nervous on their 

 behalf, and would not allow them out of 

 shelter. She kept pulling them back as first 

 one and then the other crawled towards the 

 exit. At last losing patience with one which 

 was specially insubordinate, she seized it by 

 the side of the neck and carried it to the tank, 

 in which she gave it a thorough sousing and 

 thence straight back to bed, where, after a 

 further short demonstration of independence, 

 it subsided. Two days later, one of the cubs 



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