521 
Birds from British East Africa . 
the trees, and I was able to get out of the boat and 
climb about amongst the nests. When I did so, the old 
Cormorants flew anxiously overhead and the young birds 
“ cawed ” loudly, while a flock of eight or ten White 
Egrets and some Ibises kept hovering near, furious at the 
invasion of their sanctuary. I believe that it has never been 
satisfactorily determined whether there are any fishes or not 
in Naivasha : none of the fish-eating birds which I shot 
there— i.e., Herons, Cormorants, Kingfishers, and Pelicans— 
ever contained fishes in their stomachs, but remains of 
frogs, four or five species of which are very common in 
the Lake; and though I looked most carefully, and tried 
with nets and lines, I never could catch or see any sign 
of fish; and yet it seems inconceivable that such vast numbers 
of large birds should subsist entirely on frogs, neither does 
it seem likely that they go to another place for their food. 
My idea is that the fish keep to the deep pools in the 
middle of the lake, and so are seldom seen, and that therefore 
it is supposed that there are none ; but it seems strange 
that none of the inhabitants of the locality should ever have 
seen one, dead or alive. 
169. Plotus levaillanti. African Darter. 
Plotus levaillanti Licht. 
Iris brown ; bill dusky brown ; legs black. 
Darters were common on the Athi and the Thika, and I 
had many opportunities of watching these most quaint birds. 
Their habit of sitting on a rock with wings extended, basking 
in the sun, is well known ; but sometimes they lie flat down 
on their breasts with wings spread out, as if to get still more 
sun. Their flight is rather strong and very rapid; and 
I think that they feed almost entirely by night. On one 
occasion, while watching an individual sitting on a sloping 
rock in the river, I was much amused to see a large turtle 
crawl up on to the stone and, with head and neck stretched 
out, look most comically at the apparently unsuspecting 
Darter; gaining confidence, it advanced further, and literally 
pushed the unoffending bird off. 
