334 BLACK-THROATED HUMMINGBIRD. 
Busily occupied in picking off these captives 
were several very sombre-looking hummingbirds. 
They poised themselves just as the others did 
over the flowers, and deftly nipped, as with deli- 
cate forceps, the helpless insects. I soon bagged 
one, and found I had a third species, the Black- 
throated Hummingbird (Trochilus Alewandri). 
Were any proof needed to establish the fact of 
hummingbirds being insect-feeders, this should 
be sufficient. I saw the bird, not only on this 
occasion but dozens of times afterwards, pick the 
insect from off the tree, often killing it in the 
act; and found the stomach, on being opened, 
filled with various species of winged insects. 
The habits of the three species differ widely. 
The Red- backed Hummingbird loves to flit over 
the open prairies, stopping at every tempting 
flower, to catch some idler lurking in its nectar- 
cells. Building its nest generally in a low shrub, 
and close to the rippling stream, it finds pleasant 
music in its ceaseless splash. Minute Calliope, 
on the other hand, prefers rocky hillsides at great 
altitudes, where only pine-trees, rock-plants, and 
an alpine flora ‘struggle for existence.’ I have 
frequently killed this bird above the line of per- 
petual snow. Its favourite resting-place is on 
the extreme point of a dead pime-tree, where, if 
