230 
PACIFIC SCIENCE, Vol. XIII, July 1959 
Fig. 6. Monk seals, while lying on beaches, push 
their noses into the sand to form shallow wallows. 
Such behavior may help the animals to keep cool and 
afford some protection from flies. Midway Atoll, Feb- 
ruary 2, 1957 (KWK 57-19-7). 
problem. We saw the first yearlings^ on De- 
cember 20. After that, we saw yearlings regu- 
larly throughout the winter. In the spring, we 
tagged six of them, apparently the entire year- 
class at Midway. One yearling was observed 
on March 27, after which none were found. 
When first seen on land, all yearlings had 
noticeably more algae on their hair than 
adults. This suggests that yearlings spend 
more lime in the water during the summer. A 
similar situation seems to exist among the 
Weddell and crabeater seals (Bertram, 1940) 
and elephant seals (Bartholomew, 1952). 
There is no evidence that monk seals mi- 
grate regularly. Of their wanderings at sea, 
we know very little. 
FOOD HABITS 
In the Wild 
The regurgitated stomach contents from a 
seal resting on a Midway beach were col- 
lected, as was the stomach of BDM 490. The 
stomach contents were identified by Donald 
W. Strasburg and other Fish and Wildlife 
Service biologists at POFI headquarters in 
Fdonolulu (see Table 9). Previously no food 
items from Hawaiian monk seals had been 
identified. However, Munro (1942) stated 
that the stomach of a seal he killed contained 
half-digested fish. 
The limited available material indicates that 
eels, which are numerous in atolls, and ceph- 
alopods comprise the major food taken by 
monk seals and that their food consists pri- 
marily of bottom inhabiting forms. It was not 
possible to determine whether the cephalopod 
remains (beaks and eye lenses) came from 
squid or octopus. Since the squid is largely 
pelagic and the octopus is a bottom form, the 
latter is more probable. 
It might be deduced that the monk seal is 
primarily a night feeder. Conger eels remain 
buried in the sand during daylight. At night 
moray eels emerge from crevices in reefs to 
hunt for food and Strasburg saw conger eels 
with their heads and parts of their bodies 
protruding from the sand at night. Cephalo- 
pods are also nocturnal feeders. It was ob- 
served that, in general, few monk seals were 
on beaches in early morning hours; but that 
during the day, their numbers there increased 
(Table 8). While camped on Laysan Island in 
late June, 1957, David H. Woodside {in lit.) 
observed, "I noted a few seals feeding in 
shallow water at night .... Their actions were 
very slow and deliberate as if they were after 
something stationary.” 
FECES: Fecal deposits are often seen on the 
beaches where the seals haul out. In general, 
the fecal matter is quite liquid but occasion- 
ally it is in lumps of claylike consistency. The 
color ranges from brilliant orange and ocher 
TABLE 8 
Hourly Variation in the Number of Seals 
Hauled Out at Midway 
number of 
COUNTS 
TIME OF 
COUNTS 
MEAN NUMBER OF 
SEALS ON LAND 
26 
0800 
14 
13 
1200 
25 
18 
1730 
29 
^Animals born in the spring of 1956. 
