EAGLE RIVER FLATS FY 00
14
the third year in a row of markedly lower fall
duction in duck use of Area CD reported in
numbers. This trend is likely related to the
1999 continued in 2000, which may be attrib-
effects of pumping and draining on both the
uted to continued and increased pumping.
amount of habitat available and the food re-
The use of the permanent ponds of Areas D
sources. Ducks utilized Areas B and D most
and B remained high, perhaps reflecting the
in fall, with highest densities in Areas B, CD,
lack of habitat or food resources in the treated
and D (Fig. II-1-6). The high percentage of
areas.
ducks reported for Coastal West reflects more
Bald Eagles
use of permanent ponds in the far west cor-
Numbers of bald eagles (Haliaeetus
ner this year than in previous years, rather
leucocephalus) were low in 2000 (Table II-1-1),
than increased use of the tidal mudflats. Ob-
servations of ducks were also recorded by in-
similar to recent years. While specific shore-
dividual pond when possible. While it was
line surveys for eagles were not conducted,
not possible to separate small ponds in com-
concentrations similar to earlier years of 50
plex systems, the use of important, distin-
or more eagles would have been noticed.
guishable ponds was recorded (Fig. II-1-7).
Lower numbers of eagles in recent years may
The large permanent ponds of Areas B and D
be due to decreased mortality of waterbirds
were important, as well as the Beaver Pond
on ERF.
in Area CD, as in other years.
Shorebirds
Changes in Fall Pond Use by Ducks
Numbers of shorebirds were combined for
Because of the ongoing treatability studies
all species, because individual species were
and attempts to reduce exposure of ducks to
not identified from the airplane (Table II-1-1).
white phosphorus, duck utilization of the
Numbers of shorebirds were lower than in
standard study areas of ERF from 1997
other recent years. Common species on ERF
include least sandpipers (Calidris minutilla),
through 2000 is compared in Table II-1-4. Uti-
semi-palmated sandpipers (C. pusilla), west-
lization of Area C increased in 2000. The re-
Figure II-1-5. Numbers of ducks observed during aerial surveys of ERF
in 2000, compared to the low and high numbers of ducks observed from
1991 through 1999. Points indicate extreme highs in spring and fall that
did not follow the general trend of duck numbers over time.
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