Cub Survival in Litters of 1,2 3, or 4

What size litter contributes the highest number of surviving cubs to the next generation? In northeastern Minnesota, it is litters of three.

The litter size (3) that contributed the highest number of surviving cubs (2.45) to the next generation was also the most common litter size; 22 (63%) of 35 litters were 3.

Litters of 1 or 2 were usually from first-time mothers. Subsequent litters from these mothers were typically 3.

Litters of 4 showed a higher death rate. Only half those cubs survived a year or more.

Litters of 5 are rare but have been reported from Minnesota, Pennsylvania, New Jersey, and New England. A litter of 6 was reported from Pennsylvania.

Litter size# of cubs

observed

% surviving more

than a year

# surviving more

than a year

 12 in 2 litters 100% 1.00
 2 16 in 8 litters 88% 1.75
 3 66 in 22 litters
 82% 2.45
 4 12 in 3 litters 50% 2.00
 Combined 96 in 35 litters 79% 2.17

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