Table 39. — Age composition of four groups of adult male seals from hauling 

 grounds, St. Paul Island, 1967 



Group 



10 



Age 



11 IZ 13 



14 15 17 li 



hauling grounds are younger than territorial 

 males on the rookeries. For example, nearly- 

 all of the latter studied in 1965 were 10 years 

 old or older, but 58 percent of the 100 males 

 taken from hauling grounds were younger than 

 10 years. Of the nonterritorial males, 42 were 

 older than 9 years, but no evidence was found 

 of an accumulation of senile males on the haul- 

 ing grounds. About half of the nonterritorial 

 males on hauling grounds are too young to com- 

 pete successfully for territories, and half are 

 old enough but are unsuccessful for unknown 

 reasons. 



Table 40 gives body length and weight, and 

 weight of paired, preserved testes for nonter- 

 ritorial males killed in 1967. Because of the 

 small sample sizes, we cannot draw reliable 

 conclusions from comparisons of these char- 

 acteristics by age, but for all ages combined, 

 the mean weight of paired testes from ter- 

 ritorial males is greater than that of paired 

 testes from nonterritorial males (table 41). 

 In addition, the mean weight of testes of 

 territorial males collected in 1965 from 8 to 

 23 June was about 13 g. heavier than that of 

 testes collected from 5 to 15 July. The body 

 weights of territorial and nonterritorial males 

 cannot be compared because territorial males 

 killed 5-15 July 1965 were not weighed. Body 

 length, however, can be compared because 

 length would probably change little within a 

 season. Sample sizes are small, but for each 

 age the mean body length of nonterritorial 



Table 40. — ^fean length and weight of body and mean weight of 

 testesi/ of 100 adult male seals from hauling grounds, by age, 

 St. Paul Island, 1967 



1/ Preserved In formalin. 



males was less than that for territorial males. 

 The comparisons are valid only if we can as- 

 sume that there are no differences between 

 years. 



30 



