DUB Ow. Bi Eee rvs N 37 
Surveyors Sight Nearly 650 Eagles 
in One-Day Winter Count in State 
by ELTON FAWKS 
For the past several years I have conducted a one-day eagle count in 
mid-February. This count goes from the source of the Mississippi River 
to below St. Louis as well as throughout the complete state. The count this 
year was on February 18 and 19. A choice of a Saturday or Sunday is given. 
(For a report on past counts refer to “Iowa Bird Life.’’) 
Lock masters, Fish and Wildlife personnel, bird watchers, and bird 
clubs took part. The St. Louis Audubon Club had approximately 100 people 
in five groups counting. 
The portion of the Mississippi River from the Wisconsin border to 
Burlington, Ia., was covered by both plane and cars. Dr. DeDecker and 
Pete Petersen flew this area Sunday, the 19th. Richard Nord of the Fish 
and Wildlife Service flew the same upper area to Rock Island on Saturday. 
Careful comparisons were made. Reports on hand at this writing (in April) 
show a total of 642 eagles sighted: 461 adults, 153 immatures, and 28 not 
aged. This is 74 per cent adults and 26 per cent immatures. 
For several years the Fish and Wildlife Service has been counting 
eagles concurrently with the annual winter waterfowl survey. This year, 
on dates close to January 9, a total of 332 Bald Eagles and 3 adult Golden 
Eagles were found. Of the Bald Eagles, 191 were adults and 141 immatures 
—an excellent percentage of 57.5 to 42.5. 
The National Audubon Society under the leadership of “Sandy” Sprunt 
also has a mid-winter count. (Sandy flies the Mississippi River each year 
in January.) Quotes from his letter follow: “We made the flight on the 
Mississippi on January 18 and 19. We saw more eagles than ever but 
fewer immatures. The total number of eagles was 869, but only 120 
were immatures. This is very low. I do NOT think that this is an 
altogether real figure. The visibility for immatures was bad on this 
count. We had no snow cover and it was a bit hazy. It is harder to see 
the brown birds under these conditions. The largest group of birds this 
year was between Quincy and the dam at Gladstone. There were only 55 
eagles at Savanna.” 
Sandy’s count was to the source of the river. On my count for this 
area we had a total of 762 birds: 558 adults, 179 immatures, and 25 not aged; 
percentages 75.7 to 24.3. We had snow cover and good clear weather. In 
1966 my count found a total of 745 eagles, 564 adults, 130 immatures, and 
51 not aged. Percentage, 81.6 to 18.4. 
This percentage gain in immatures is encouraging, but when we 
compare the very high percentage of young in the January waterfowl 
survey with the later counts, then we must wonder. Did these immatures 
go elsewhere, or was it a decline in numbers? If so, why? Can the natural 
mortality rate for immatures be that high? Are the dark colored eagles 
mistaken for hawks and shot? Immature eagles do range farther afield 
than the adults and are seen near smaller streams and are higher in 
numbers around game refuges. This accounts slightly for the greater 
number found in the Fish and Wildlife January waterfowl survey— 
however, by comparison with additional data on hand, only slightly. The 
immatures either left the state or didn’t survive. Perhaps when additional 
data is received, a clue might be found. Reports to me from states north 
of here show no build up in numbers of immatures. 
—2309 Fifth Ave., Moline, Illinots 
