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The peccary is one of the least studied game mammals in North America. The Arizona Unit has found it prolific 

 and adaptable to its desert or semidesert range. (Photo by L. K. Sowls) 



This game animal lias shown high potential pro- 

 ductivity. Females bear young at less than 1 

 year of age and breed again in slightly over 1 

 month when the young are lost. The early breed- 

 ing age and ability to breed again soon after loss 

 of young are important factors in maintaining 

 populations at fairly high levels. 



Bighorn s-heep. — Periodic observations by Mon- 

 tana Unit personnel were made on W color-marked 

 bighorn sheep of known age on Wildhorse Island. 

 Nineteen lambs were tagged in May of 1959, nine 

 of which were known to be alive in June of 1962, 

 37 months later. Eleven lambs were similarly 

 marked in the spring of 1900 and three were alive 

 25 months later. Only 7 of Itt lambs tagged in 

 May of 1961 were known to be alive at the age of 

 13 months. Survival of lambs to adulthood was 

 somewhat in favor of males, 44 percent of which 

 were alive at the end of tiie observation period, 

 as compared with 38 percent of tlie females. Rams 

 had a longer life span than ewes, resulting in an 



unbalanced sex ratio in favor of males in this un- 

 hunted population. 



Cottontail chemistri/, biology. — In an Ohio Unit 

 study with cottontail rabbits, preliminary analy- 

 ses showed that sex was significantly related to red 

 blood cell volume, serum calcium, and dry liver 

 weight. The serum calcium-phosphorus ratio was 

 related to the age of the specimen. Cottontails 

 collected from eastern and southeastern Ohio had 

 significantly lower bone calcium, bone-calcium-to- 

 phosphorous ratios, and dry liver weights than 

 those taken in west-centi'al Ohio. 



Tn anoilicr Ohio study the numbers of corpora 

 lutea, iini)huitation sites, and living embiyos 

 found in pregnant cottontails taken in four dif- 

 ferent physiographic regions of Ohio differed 

 significantly. The lowest rei^roductive rate was 

 in animals from the imglaciated sand.stone and 

 shale region of .sotuheastern Ohio. Variations in 

 the ovulation rate, rallier than total prenatal mor- 

 tality, seemed the cause of regional differences in 

 productivitv. 



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