894 | Philippine Journal of Science 1920 
often makes a deafening sound. A woodpecker may make the 
woods ring with his harsh cali or a large hornbill awaken the 
echoes with his loud weird ‘“‘au, calau au au;” as he flaps slowly 
away, his wings produce a curious rustling sound. 
Now a familiar bird note may come faintly from the high 
leafy branches as at a distance—“te-dee, dee dee dee.” Wait, 
it is coming this way. There it is again, and it sounds like a 
chickadee. No wonder, either, for it really is a chickadee—a fine 
black and yellow chap, Pardaliparus elegans (Lesson) or a re- 
lated species, that is not very much different from some of its 
American cousins. That long-tailed nervous thing with a harsh 
voice is a flycatcher, Rhipidura cyaniceps (Cassin) ; let it go, 
the branches overhead are full of birds. We are in the midst 
of one of the wandering bands that are characteristic of the 
forest. There is a fine male Cyanomyias celestis (Tweeddale) — 
a gem among flycatchers; one good specimen of that is worth 
a day’s work. Look carefully for the small quiet ones. The 
rare species of Zosterornis go in these flocks. What is that 
you have picked out from the end of a high branch? A rare 
warbler? Yes, rarein North America. That is Acanthopneuste 
borealis (Blasius), one of the worst pests of the collector. It 
is an abundant migrant in the Philippine Islands, and because 
of its pale gray and greenish yellow colors it is difficult to iden- 
tify as it flits among the leaves. , 
If you have had good luck you have been able to recover two 
or three good specimens from this flock, which has now passed 
on its way. Perhaps you have lost as many more, some having 
lodged in masses of epiphytic plants far from the ground, others 
being hopelessly buried in a rank growth of ferns. The last 
you hear of the flock are the calls of the chickadee and the nut- 
hatch as they fade in the distance. The silence is now oppres- 
sive, for there is absolutely not a sound. 
Where do these wandering bands come from and where do 
they go? What leads such a variety of kinds to travel together? 
Here are chickadees, nuthatches, flycatchers, thickheads, silver- 
eyes—birds of various families, but all insect-eaters. Do they 
secure any protection by traveling together? It is doubtful if 
they need it, for hawks cannot work to advantage among the 
branches of the forest trees. It is possible that these birds take 
pleasure in each other’s company, but that is mere surmise. 
It seems more probable that several or many birds traveling 
through the tree tops disturb the insects upon which they feed, 
