370 
PACIFIC SCIENCE, Vol. XX, July 1966 
TABLE 3 
Stomach Contents of Rodents Captured in Gulches 
FOOD ITEMS 
Rattus exulans 
NO. 
examined: 146 
Rattus rattus 
NO. 
examined: 123 
Mus musculus 
NO. 
examined: 25 
Rattus norvegicus 
NO. 
examined: 3 
FRE- 
QUENCIES 
NO. % 
VOL. 
% 
FRE- 
QUENCIES 
NO. % 
VOL. 
% 
FRE- 
QUENCIES 
NO. % 
VOL. 
% 
FRE- 
QUENCIES 
NO. % 
VOL. 
% 
Fruits and berries 
18 
12.3 
9-4 
41 
39.8 
30.5 
1 
33.3 
33.3 
Grass (seeds) 
4 
2.7 
1.7 
14 
13.6 
10.1 
6 
24.0 
14.6 
Grass (stalks) 
30 
20.5 
17.7 
28 
27.2 
23.2 
Insects 
20* 
13.7 
2.9 
5* 
4.8 
2.2 
6 
24.0 
5.6 
Insects (egg mass) 
4 
16.0 
14.0 
Insects (larvae) 
2 
8.0 
0.6 
Sugar cane 
76 
52.0 
51.8 
8 
7.8 
6.3 
1 
33.3 
21.6 
Nuts 
8 
5.5 
6.2 
12 
11.6 
10.7 
5 
20.0 
23.3 
Unidentified materials 
11 
7.5 
7.2 
14 
13.6 
11.5 
7 
28.0 
41.9 
2 
66.7 
45.0 
Animal flesh 
5 
3.4 
3.0 
6 
5.8 
5.0 
Other invertebrates 
(earthworms, slugs, etc.) 
1 
1.0 
0.3 
* Includes adults, larvae, and egg masses. 
R. rattus diet. Insects and unidentified materials 
occurred in uniform frequencies, but the latter 
items were greater in volume. Trace amounts 
of rodent flesh and pelage were found in a 
single specimen. Kukui nuts and the lower in- 
vertebrates were absent from the diets of R. 
rattus from cane fields. Because of the small 
sample size, no comparison between summer 
and winter feeding pattern was made. 
Mus mus cuius: Insects, primarily egg masses, 
and seeds of Digit aria henryi, Paspalum conju- 
gatum, and Panicum maximum comprised 
38.8% and 32.0% respectively of the food 
materials of Mus. Sugar cane, an important 
source of food for R. rattus and R. exulans, was 
of little importance to this species. Only 7.2% 
of the mice fed on cane and it formed a mere 
9-8% of the volume. Unidentified materials 
constituted 10.9% of the volume. Other food 
items such as fruits and berries, nuts, animal 
flesh, and lower invertebrates amounted to 
5.5% of the diet. No apparent differences in 
the feeding pattern between winter and sum- 
mer were observed. 
Gulches (see Table 3) 
Rattus norvegicus: The Norway rat was the 
least abundant rodent in the gulches; only three 
were captured. Fruit of the Java plum was the 
only food item in one specimen, materials in a 
second rat could not be identified, and the third 
had eaten 65% sugar cane along with 35% 
unidentified materials. 
Rattus exulans: The major food source of 
the gulch-inhabiting R. exulans was sugar cane. 
This item occurred in 52.0% of the rodents 
and formed 51.8% of the food materials. Grass 
stalks were taken by 20.5% of the rats and 
amounted to 17.7% of the volume. 
In the gulches many animals fed on kukui 
nuts, guava fruits, and berries. These items 
formed 15.6% of their diets. Although insects 
were found in 13.7% of the animals, they 
amounted to only 2.9% of the volume. The 
remaining 11.9% of the food materials con- 
sisted of grass seeds, animal flesh, and uniden- 
tified matter. 
Rattus rattus: The preferred foods of R. rat- 
tus in the gulches were seeds and stalks of grass, 
and guava fruits. These items constituted 33.2% 
and 30.5%, respectively, of their diet and oc- 
curred in 40.8% and 39.8%, respectively, of 
the animals. Gulch R. rattus also fed more on 
kukui nuts than on sugar cane. Nuts were con- 
sumed by 11.6% of the animals and amounted 
to 10.7% of the volume, while cane was eaten 
by 7.8% of the rodents and amounted to 6.3% 
of the volume. 
