22 THE AU DU BO WNe Bo bese 
A feature of the report for Illinois was the high count of 206 eagles (only 
10 were immatures) at the Savanna Ordnance Depot. Daily counts at Lock 
and Dams 19 and 20 showed eagles leaving daily. A drawdown in water 
level in Pools 14 and 15 caused the ice to leave and scattered the eagles. 
The late date for this count did catch the eagles in migration. An earlier 
February date is suggested for the future. This should follow the U.S. Fish 
and Wildlife count that is taken in their Annual Waterfowl Inventory. 
Eagles are now counted and their ages are noted in this survey. 
When the present count is compared to the count for January 31, 1960 
(see The Audubon Bulletin, number 113, March, 1960), we find the follow- 
ing interesting data: 327 Bald Eagles were found in 1961; 302 were adults 
and 25 immatures. This gives a ratio of 92.355% adults to 7.645% im- 
matures. In the 1960 count we had 104 eagles seen clearly enough to deter- 
mine age; 82 were adults and 22 immatures. This was 78.75% adults to 
21.25% immatures. 
When we omit the eagles seen in 1961 at the Savanna Ordnance Depot, 
which was only partially covered last year, we find 121 Bald Eagles, 106 
adults to 15 immatures, giving percentages of 87.6 to 12.4. 
We found the eagles in migration in the February 1961 count. The same 
thing happened in our Tri-City Bird Club Christmas Census, December 26, 
1960. In this count we stationed observers on both sides of the Mississippi 
River and counted eagles at the same time so as not to have a double count. 
We found 91 Bald Eagles. Of this total, my party counted 35. Later in the 
day we were on the bluffs nearby and several groups of Bald Eagles were 
seen spiraling high in the air. Groups of from 6 to 18 were seen, appearing 
from the east and drifting west, following the river. The upper ones were 
so high that they could hardly be seen without glasses. They were flying in 
circles, each layer directly under the one above. One group of 30 was 
counted, and several smaller numbers were seen. One adult eagle rose 
straight up, with head up and tail down, and repeated this maneuver four 
times as it flew past. It hovered in one spot for about 18-20 wingbeats. 
When the last group passed, we hurried back to the spot where we had 
counted the eagles earlier and found 21 still there. 
Route #1, Box 112, East Moline, IIl. 
OBSERVATIONS OF A NESTING COLONY 
OF EGRETS AND HERONS 
By J. W. GALBREATH 
Two TRIPS WERE made this summer to a nesting area in Grand Marais 
State Park, Ill. — from 6:00 p.m. to 9:00 p.m. on Monday, June 26, and 
from 5:00 a.m. (sunrise) to 8:00 a.m. on Wednesday, July 12. Pairs of 
brooding Black-crowned Night Herons are using about 15 large elm, hack- 
berry, and pin oak trees in the south wooded area of the park. 
American Egrets have been seen nesting in the area for at least four 
seasons and the herons for approximately ten years. Residents living 40 
rods to the south of the breeding colonies have often reported the offensive 
odor from the droppings, dead young which have fallen from the nest, and 
decaying fragments of fish. 
Herons and egrets nest in the same trees, but rarely. The egrets seem to 
prefer elm trees, while the herons use elm, hackberry, and pin oak, in that 
