162 Department of Conservation of Louisiana 



In building dams, beavers work from the upstream side, 

 Bailey says. Sticks, leaves, grass, sods and mud are laid 

 across the stream, and are added to until a water flow is 

 checked and the level begins to rise. Then, as it rises, 

 sticks are pushed over the top and allowed to lie criss-cross 

 on the lower slope, bound and securely held by mud and 

 earth added to the top and upper slope until the dam is 

 high and strong enough to hold water in the pond at the 

 desired level, impervious to leaks. 



That the beaver is endowed with sufficient mechanical 

 and engineering knowledge to build its dam in a perfect 

 semi-circle calculated to resist water pressure, theoretically 

 as well as practically, is not true. It possesses no such 

 ability. It can, and does, lay a haphazard structure across 

 a stream and while the site is usually selected at a logical 

 place for such work, the dam is sometimes a successful ac- 

 complishment and sometimes it is not. 



Besides building dams, the beaver of the north also 

 builds houses, but the Louisiana beaver appears to neglect 

 this activity and confines its home-building to making ex- 

 cavations in the banks of the streams where it lives. The 

 entrances to these subterranean quarters are below the sur- 

 face of the water and extend upwards so that the living 

 chamber and nursery is above the water level. 



As very little research work and study has been done 

 on the beaver colonies in Louisiana, it is necessary to pre- 

 sume a great deal as to their habits. A desire to leave the 

 colonies undisturbed to allow the population to increase has 

 been responsible for the fact that so little scientific atten- 

 tion been paid to this very interesting animal. 



It is presumed that our beaver breed earlier than do 

 the beavers of the northlands. The time of mating and 

 the period of gestation are not known, but the young appear 

 in May, and a few as late as June. Therefore, it is not un- 

 likely that the young should appear in March and April in 

 Louisiana. There is no evidence to show that there is more 

 than one litter a season. Bailey finds that in the north 

 beavers apparently begin breeding when they are a year 





