The Fur Animals of Louisiana 65 



most studied fluctuation, and Professor V. W. Jackson, in 

 his "Fur and Game Resources of Manitoba," claims that 

 periodic fluctuatoins in the fur catch of that Canadian prov- 

 ince can seldom be ascribed to the effects of trapping, but, 

 rather, to natural causes, such as food supply, weather con- 

 ditions, and widespread epidemics. These go in cycles of 

 plenty and scarcity, of severity and salubrity, and depend- 

 ent animal life seems to vary accordingly. 



Herbivorous animals seem to vary slightly with the 

 vegetation and largely with epidemics of widespread dis- 

 ease, Professor Jackson said, while carnivorous animals 

 seem to die from exposure and starvation in winter. The 

 flesh-eaters do not usually seem to have specific epidemics 

 on the same large scale as the vegetable feeders, he states, 

 and in his study of statistical reports extending over a 

 century of fur-trading in the north shows that the peak 

 years of rabbit abundance were 1845, 1855, 1877, 1887, 

 1897, 1905, 1917, and of lesser abundance in 1924. This 

 approximates an eleven-year cycle, according to Professor 

 Jackson, and he cites Elton's suggestion of association of 

 sunspot maxima and the eleven-year cycle with its concomi- 

 tant effect upon vegetation, tree growth, and water levels 

 and other natural conditions. And, as might be expected, 

 the abundance and scarcity of lynx, fox, and wolf is coinci- 

 dent with that of the rabbit of the north. This study of the 

 almost perfect correlation of the rise and fall of the rabbit 

 population with the animals that prey on them indicates 

 a provision of some kind to maintain a balance of nature. 



"This periodic abundance of rabbits and sudden decline 

 is a perfectly normal happening," claims Professor Jackson. 

 "In good or favorable years the fertility of rabbits is much 

 increased, there being eight to ten young in a brood, instead 

 of five or six, and two or three broods instead of one. The 

 district becomes surcharged with rabbits, food fails, epi- 

 demics break out, and the population is destroyed in a 

 season." 



While those interested in the perpetuation of the fur 

 industry in Louisiana cannot point out any direct connec- 

 tion between the "year of no rabbits" of the north with the 



