The Zoologist— January, 1870. 1963 



I have read that the beaver breeds at any time during the year ; 

 but this cannot be, or all the kittens that are trapped in the fall would 

 not be of the same size. It produces from three to four at a birth. 

 The teats are placed between the fore legs. The young (called 

 kittens) whimper like young puppies when suckling, even when two 

 months old. The females prefer deep sedgy lakes to bring their 

 young up in, and they feed on grass about that time of the year (July 

 or August). They feed on willow about April, May and June. I 

 cannot say whether they are born blind or not, but suspect so. They 

 are very fond of water-lilies [Ntiphar advena; Aii.) in the spring. It is 

 with me a matter of uncertainty whether the female litters in a house, 

 under the ground, or in the dry sedges; but I should think, under 

 ground or in the houses. In the autumn more females are caught 

 than males. Trapping commences in September and continues to 

 May; after that the trappers leave them alone, so that I do not know 

 much about their doings in the summer. 



They begin to build their dams about July or August, as soon as 

 the summer floods begin to subside. For this purpose they generally 

 choose a bend in the stream, with high and clayey banks, and com- 

 mence by felling a large tree that will reach across the water ; or they 

 fell a tree on each side of the water so as to meet in the centre. They 

 then float slicks from six to four feet long down to the dam, and lay 

 them horizontally, filling in the spaces with roots, tufts of grass, 

 leaves, and clay or mud. The branches of the first tree are the 

 perpendicular supports, almost all the remaining sticks being placed 

 horizontally and crosswise. The last six or eight inches in height 

 is very insecurely constructed, being nothing but mud and leaves. 



The highest dam I ever saw was only about four feet six inches ; 

 but the generality of them are not above two or three feet. The 

 action of the water by bringing down mud, gravel, or fallen leaves, 

 strengthens the dam by making a sloping bank against it; and, the 

 willow sticks of which it is composed sending forth their roots and 

 shoots, the dam in course of time becomes a fixture bound together as 

 strongly as well could be. The winter floods almost invariably 

 destroy the upper part of the dam, which is reconstructed afresh every 

 year. The shape of the dam is almost always semicircular, with the 

 crown of the arch down stream, thus reversing the order of things ; 

 but 1 have no doubt this is in consequence of the heads of the first or 

 principal trees being floated down stream when they are first thrown. 

 The body of water raised by these dams varies, of course, according 



