Hawaiian Monk Seal — Kenyon and Rice 
245 
Fig. 14. Molting adult female, ventral view. Sloughing of hair and epidermis during the molt begins around 
the head and neck, progressing posteriorly and ventrally. The lower back and hind flippers are last to complete 
the molt. Green Island, Kure Atoll, June 5, 1957 (KWK 57-22-3). 
Growth and Body Size 
PUPS and yearlings: Seal pups and year- 
lings were weighed on 100-pound capacity 
Chatillon spring scales (Fig. 16). When an 
animal exceeded the capacity of the scale, two 
were used in combination. A steel tape was 
used to measure living pups and yearlings. 
Because they squirmed energetically, the 
length measurements (straight line, tip of 
nose to tip of tail) are not exact. However, the 
error probably does not exceed ± 1-2 cm. 
and the mean values are, therefore, useful. 
Measurements other than standard length 
were virtually impossible to obtain with our 
technique from living yearlings. 
At birth, the pup weighs about 35 to 38 
pounds and its length is roughly 95 to 100 
cm. (Table 10). At the age of 17 days, the 
weight of pup MS- 13 had doubled; at age 28 
days, its weight had tripled; and when last 
weighed during the nursing period, at the 
age of 37 days, its birth weight had nearly 
quadrupled (Fig. 17). At Midway, the mean 
weight of three normal pups at the time of 
weaning was 133 pounds (Fig. 12). At Kure, 
the largest nursing pup observed had an esti- 
mated weight of 150 pounds; the estimated 
weights of recently weaned pups ranged from 
95 to 160 pounds. The length and girth of 
only one normal pup at the time of weaning 
was recorded. This pup (MS- 13) weighed 142 
pounds, its length was 122.5 cm. and its 
girth was 108.3 cm. Its "'degree of fatness” 
was, therefore, 88.4 (c/. Laws, 1953; Sivertsen, 
1941; Smirnov, 1924). 
After the pup is weaned, it steadily loses 
weight. Since it has grown relatively little in 
length during the nursing period, it is ex- 
ceedingly fat when weaned (Fig. 13) and ap- 
parently takes no interest in food. (The 
apparent increase in weight shown for MS- 10 
