362 
TABLE 4 
Food Items in Stomachs of Six Mice from 
Manana Island, Hawaii 
ANIMAL no. 
FOODS IDENTIFIED 
27 46 
Nicotiana tabacum seeds 
2747 
Grass stems, leaves, and fruits; 
insect fragments 
2748 
N. tabacum seeds; 
grass fruits 
2749 
Atriplex semibaccata fruits and bracts; 
anthers of grass flowers 
2750 
N. tabacum seeds 
2751- 
N. tabacum seeds 
cause host chains are often incomplete and the 
colonizing stock may have been relatively para- 
site-free. In spite of these limitations, remark- 
able adaptations may occur if a parasitic species 
is pressed for survival. Such adaptations are 
found among the ectoparasites of birds and 
mammals on Manana. A total of 13 species are 
recorded, with two collections of Mallophaga 
from birds identified only as to genus. Of these, 
6 species are primarily parasites of mammals and 
7 are primarily parasites of birds. The ecto- 
parasites of mammals are much better known 
than those of birds because the two species of 
mammals have been examined more thoroughly 
than the numerous species of birds. 
DIPTERA 
HIPPOBQSCIDAE 
Olfersia aenescens C. G. Thomson 
6 $ $ , ex Anous stolidus and/or Sterna 
jus cat a, July 17, 1963 
1 $ , ex Oryctolagus cuniculus, Feb. 29, 
1964 
This hippoboscid is a common parasite of 
oceanic birds of the families Phaethontidae and 
Sulidae (Pelecaniformes) and Laridae (Cha- 
radriiformes) . There are previous records of 
this species from Manana, and the specimen 
reported by Bryan (1935) as Olfersia spinifera 
was reidentified as O. aenescens by Maa 
(1962). During the summer months when 
large numbers of sea birds are nesting on the 
island, this species can be seen flying about and 
may be caught easily by sweeping with an insect 
net. 
PACIFIC SCIENCE, Voh XXII, July 1968 ( 
The specimen collected from a rabbit is cer- 
tainly an example of straggling which probably 
resulted from the dose association of rabbits 
and birds on the island. The fate of adult flies 
during the winter months when sea birds are ; 
absent from the island is unknown. 
SIPHONAPTERA 
PULICIDAE 
Ctenocephalides fells fells (Bouche) 
3 ' £ S , 2 $ $ , ex Oryctolagus cuniculus, 1 
Aug. 31, 1961 
80 $ $ , 11 A 9 $ , ex Oryctolagus cuni- 
culus, Feb. 29, 1964 
C. f. fells seldom has been reported from 
O. cuniculus, and the only records of which we 
are aware are those of Cable (1943), Seddon 
(1947), Hopkins and Rothschild (1953), 
Mykytowycz (1957), and Smit (1957). The 
last author lists the occurrence on O. cuniculus 
in England as accidental. Mead-Briggs (1961; 
1963) examined over 53,000 fleas collected 
from rabbits in England without finding C. f. 
fells. 
Of the 13 rabbits collected on Manana, 8 
were examined for ectoparasites. Conditions 
were such that it was impossible to collect all 
of the fleas seen and it is estimated that only 
about one-third of those on the 8 animals were 
collected. Cat fleas were very common on the 
body but were found only rarely on the head of 
the rabbits. The greatest concentrations were 
on the back of the neck. 
The finding of large numbers of cat fleas on 
rabbits on Manana indicates this species is 
capable of maintaining itself on this host under 
certain conditions. This is the first recorded 
instance of a naturally occurring population of 
C. f. fells on feral O. cuniculus. The flea could 
have been introduced to Manana on the rabbits jj 
or at various times by dogs or cats brought 
ashore by fishermen. 
The C. f. fells from Manana might be a 
suitable strain for laboratory culture inasmuch 
as its host, the rabbit, is more convenient to 
maintain than other hosts. Dogs or cats have 
been used (Smith and Eddy, 1954; Hudson and 
Prince, 1958) but necessitate more care and 
space than would rabbits. Attempts have been 
made to rear cat fleas on laboratory and wild 
