244 
PACIFIC SCIENCE, VoL XIII, July 1959 
This is the usual pelage color of winter and 
early spring. 
Adult males are generally darker than fe- 
males. Some appear almost blackish on their 
backs and sides. However, a very large dark 
female was seen, and a nearly adult male was 
as light as any female seen. 
The length of hair on an adult male (BDM 
490) ranged from 2 mm. on the flippers to 
9 mm. on the belly. The individual hairs are 
quite stiff and when dry stand fairly erect. 
ADULT MOLT: In the subtropical climate of 
the Leeward Chain, the air temperatures are 
mild and comparatively uniform (see cli- 
mate) and seasonally the hours of daylight 
vary less than at higher latitudes. As might 
be expected under such conditions, the molt- 
ing of various individuals is spread over a 
long period. 
The first molting adult, a large female, was 
seen on May 13. Her molt was complete ex- 
cept for a few irregular ragged patches of 
loose skin and hair on the lower back. A sub- 
adult male, partially molted, was seen on 
May 23. Among a group of 66 seals seen on 
June 5, 8 adults and 2 subadults were in the 
process of molting. Thirteen adults were 
closely observed on the same day. Of these, 
2 had completed their molt and 3 had not 
begun to molt. Among 8 subadults, 7 had 
not yet molted and in 1 the molt was one- 
third complete. Molting subadults were ob- 
served on July 29, August 15, and November 
18, 1957; molting adults as late as September 
10 and 20, and October 1 and 11. 
In general, adults appear to molt earlier 
than subadults. However, no adult females, 
either in fresh pelage or in the process of 
molt, were seen with nursing pups. Because 
of the extent of the pupping season, it is 
probable that some adult females do not be- 
gin their molt until midsummer or later. 
A subadult male captured in October, 1955, 
and held in the Waikiki Aquarium molted in 
the fall of 1955 and again in April of 1957, 
and a female in October of 1957 (S. W. Tinker 
and K. A. Wong, in lit.). 
The molt begins around the face and neck, 
proceeding posteriorly along the belly and 
sides, so that the central dorsal region and 
hind flippers are last to molt. 
Molts subsequent to the first postnatal 
molt, except for their progression from an- 
terior to posterior and from ventral to dorsal, 
are quite different from the first molt. The 
process of molting for the elephant seal is 
described by Laws (1956). It is said to be 
"unique, not only among the pinnipeds but 
among the mammals,” and has been called 
"reptile-like.” We were, therefore, interested 
‘to observe that Laws’ description of the molt 
in the elephant seal applies remarkably well 
to that of the adult and subadult Hawaiian 
monk seal. 
When the faded brown and straw-colored 
hair sloughs off during the spring and sum- 
mer, it comes off in sheets and patches (Fig. 
14) still imbedded in the outer layer of the 
epidermis (Fig. 15). One patch of shed skin 
and hair picked up from the beach beside a 
sleeping adult female, measured roughly 
170x100 mm. The hair roots protruded 1 
mm. from the lower side, and the old hair 
8-10 mm. from the top. When this animal 
was examined from a distance of about 2 feet, 
it appeared that where the hair and adhering 
epidermis had been freshly lost, little or no 
new hair yet protruded from the blackish, 
rough skin. However, on the chest and shoul- 
ders, the slightly protruding new growth gave 
the surface a faint silvery sheen. 
No animal was seen to roll or scratch to aid 
the loss of loose patches of skin and hair. 
Molting seals seemed to behave as usual, both 
in and out of the water, except for one adult 
male on October 1 which was reluctant to 
enter the water and charged the observer with 
threat display. The captive animal mentioned 
above fasted during the several weeks of 
molting. However, the female captured in 
August, 1955, "ate a fish or two a day but 
without any spirit” while molting (S. W. 
Tinker and K. A. Wong, in lit.). 
