56 
THE CONDOR 
Vol. XVIII 
like other divers, they would tip over on their bills and disappear for a few 
moments at a time. 
One of the big fellows did sit up and take notice when a Marsh Hawk I 
had been watching came out and squealed at me. The transformation was 
amusing. From lying prone on the water head and neck down, it came up at 
attention, L, neck drawn high, head alert, and even its short tail tipped up. In 
a moment, as nothing came, back it dropped at ease, full length on the water. 
In bathing, Oidemia threw off its usual lethargy, ducking, flapping, spatter- 
ing, and splashing like a canary in a tub. On hearing a noise down the shore 
one day I was surprised to see one of the big black Ducks go rushing back 
and forth through the water and then rise and flap its wings till their white 
flags waved. When a week later I saw the encounter of the rivals, it strength- 
ened my suspicion that Oidemia had been showing off. 
The white flags show far across the lake and when the great birds fly 
evenly low over the water the velvety black of the males makes the snow white 
a conspicuous mark. The disappearance of these white banners when the 
Scoter drops to its nest is not significant because the bushes hide it then, and 
the disappearance of the banners when it lights on the water would hardly 
deceive any enemy, for Oidemia is so large and black it stands out across a 
lake. But on the other hand, to a female Scoter happening to be under water 
when her mate flew, might not the white flags be a decided help in distinguish- 
ing him from black-fronted Scaups scattered out over the lake? When seeing 
a group of black-fronted Ducks, large and small, on the water one day T 
thought I had at last, found a family of Scoters, but on nearer approach the 
small ones proved to be Scaups! Tf it he true that the Scoters remain paired 
throughout the year and the two forms deglandi and americana are together 
in winter the white eye- and wing-patches may well be of use in helping pairs 
keep together, especially in flight. In taking flight, the Scoters usually 
seemed to rise easily, but one that I watched flapped and splashed for some 
time before lifting its heavy weight. 
As you watch these great black Sea Ducks sitting like decoys on the still 
water or flying over a smooth lake, they seem decidedly out of place. But 
wait till a heavy wind has been blowing for a few days, waves are hammering 
the shore and all the other Ducks have retreated to sheltering bays. Then 
perhaps you will see, as I did, a pair of Oidemia head out around a point into 
the teeth of the wind, and as you marvel at their temerity see them settle them- 
selves to ride the billowing waves in their own proper marine character. 
The few Ducks of Stump Lake were always interesting to watch in their 
quiet feeding bays and along the shores both for what they were and what 
they might be, for one unseen before might appear at any moment. But the 
spectacular birds of the lake were the Gulls and Terns. 
The Black Terns are always striking birds, and at Sweetwater Lake there 
were so many of them that it might have been called the Lake of the Black 
Terns. Hydrochelidon, Water Swallows, they certainly are, flocks of them 
skimming low over the surface of the lake, hack and forth; hordes of them 
trooping across the passes and weaving in and out across the sky, their harsh 
grating kek'kek commanding attention from the shore. 
As I sat behind the trees and watched them, fascinated by their maneuvers, 
they hunted close along shore, their actions much like those of the white Tern. 
On long-pointed wings one would approach, the silver line from neck to elbow 
