226 Department of Conservation of Louisiana 



ana muskrat has been designated as the leader in the num- 

 ber of litters and the number of young in each litter pro- 

 duced. The enormous output of the Louisiana marshes 

 each year is attributed to this by writers on the subject 

 who evidently have not taken into consideration the large 

 area of marsh habitat. 



A mature study of the breeding habits of the muskrat 

 in Louisiana indicates the necessity of recognizing a number 

 of points not usually considered germane to the subject- 

 matter by many who have more than a passing interest in 

 this fur animal. Periodic fluctuations in fecundity are 

 known to be common to a number of mammals, particularly 

 rodents, and the increases in some years and the decreases 

 in others may be attributed to this phenomena of seasonable 

 variation and not to trapping. 



The question of mating seems to have been answered. 

 While it is true that there was some doubt that the male 

 muskrat mates with more than one female, our researches 

 and the records from those who have bred this animal in 

 pens on fur farms indicate that the boar is polygamous; 

 therefore, there is no reason for longer believing that the 

 muskrat of the wilds is ever strictly monogamous. This 

 has an important bearing on the rate of increase, for it 

 means that more females will produce young than if it 

 were necessary to have paired parents to insure the stock 

 for the next season's breeding. 



While it does seem certain that the female Louisiana 

 muskrat has from three to five litters of young a season, 

 we have yet to prove that one individual mother 'rat lias 

 produced that number of litters in one twelve-month. We 

 do not know that females here can produce more than seven 

 young to a litter, four seems to be the normal number, and 

 how great the mortality is among the mice out in the marsh 

 we do not know. 



This lack of definite information on a very important 

 phase of our study of the muskrat indicates the necessity 

 of a continuance of the research already begun. 



