Mar., 1911 NESTING OF THE FORSTER AND BLACK TERNS IN COLORADO 
61 
swerved to barely miss our heads would give utterance to a shrill scream, which, 
coupled with a sudden booming of the wings, was altogether disconcerting. We 
often had the birds swoop so close to us that we could plainly feel the rush of air 
from their wdngs. 
A few Black-crowned Night Herons were ne.sting among the terns, and one 
unfortunate youngster, unable to fly, who deserted his nest at our approach, took 
refuge on a tern’s nest, where he w’as promptly attacked by half a dozen of the 
birds, and although twice as large as his assailants, was knocked down repeatedly, 
by well directed blows of the birds’ wings, until he finally sought safety in 
the water. 
We frequently saw the birds flying about with small fish in their bills, and on 
one occasion a minnow about two inches long was found in a nest contain- 
ing young. 
We found one unfortunate bird suspended by the neck, between two upright 
cat-tail stalks, just above the crotch, on which in its frantic efforts to liberate itself 
it had sawed its neck painful- 
ly. Our timely arrival prob- 
ably saved it from a tragic 
death, as it was almost ex- 
hausted when we liberated it. 
BLACK TERN 
Also beautiful, and even 
more interesting to us than 
the Forster Terns because ol 
'' the mysterious manner in 
which their breeding ground.- 
eluded our search were tlu 
Black Terns (.Hydrochelidcn 
!/ .s/o'i/ia?ne>ist's ) . These dain- 
ty little fellows were fully as 
abundant in point of numbers 
as the Forster Terns, but al- 
though we saw numbers of 
birds on every trip, careful 
and' thorough searching failed to discover a nest during the breeding season of 
1906, and that of 1907 was almost gone, before the coveted prize was discovered. 
The birds appeared early in May ( May 11, 1907, is my earliest record), and a 
week later were common. On May 17, 1907, one flock of sixty-five birds was 
seen (apparently migrants), and on May 17, 1908, two flocks of fully one hun- 
dred birds each were observed at the lakes. Soon after arriving the birds would 
become wonted to some certain pond or lake, and here amid their threatening 
screams and complaints we would splash through waist deep water by the hour, and 
plow through acres of soft black ooze, and decaying cat-tails, in a fruitless search 
for the nests. 
Finally on July .5, 1907, after nearly all the rest of the birds had finished their 
nesting, and after we had about given up hope of finding the Black Terns’ nests at 
all, the happy di.scovery was made, and I can do no better than to quote from my 
note-book of that date. 
“There were only four Black Terns on the lake, as near as we could tell, and 
we worked the whole lake over, and then found the ne.st by coming back to the 
