Date: 8/22/24 11:59 am From: Doug Jenness <dougjenness...> Subject: [AZNMbirds] San Carlos Lake
22 August 2024
For 18 months, from January 2023 to early August 2024, the water level at
San Carlos Lake did not go below 225,000 acre-feet, and much of the time
was much higher. The last time it was above 225,00 acre-feet was briefly in
2010. The recent level was the longest sustained high water level at the
lake in this century. One of the consequences is that much emergent
vegetation along the shores was flooded and created good nesting
conditions for Clark's and Western Grebes. Nesting has been occurring
continuously for the past 13 months and is still continuing. Only in three
previous years since 2004 has nesting been detected at the lake, and for
much shorter periods.
Another result was that for much of the past year mudflats and
flooded grassy shores were absent and few shorebirds and wintering
waterfowl and pelicans were present. However, in recent weeks, the water
level has been dropping and some mudspits and islands are beginning to
appear. The largest mudflat so far is around the Monument on the north
side of the lake near the mouth of the San Carlos River. Shorebirds are
beginning to show up there as well as gulls and terns. The pelican
population is also growing.The stocking of the lake with 20,000 black
crappie and 30,000 channel catfish in May 2023, the first time in many
years, has helped increase the bird population. I anticipate that through
the fall and winter this year birding will be good at the lake. Several
rarities have appeared including a Lesser Black-backed Gull, third record
for the lake, if accepted by the Arizona Bird Committee, and a Laughing
Gull, the fourth record for the lake. An Iceland Gull is being reported
from the Monument area, likely the same one that has been reported at the
lake since 27 December 2023. On that date Keith Kamper and I observed a
first-winter Iceland Gull on a small rock island on the south side of the
lake on 1 July. At that same location I observed an immature Iceland Gull
that was transitioning from first to second winter plumage, and others
reported it until 10 July. Paul Heveran and I discovered an Iceland Gull at
the Monument area on 13 August that also appeared to have similar plumage
as the bird seen in July, though is a bit more ratty. Given the rarity of
Iceland Gull in AZ and the plumages of this bird, the ABC will have to
consider whether this is one or three records. The July and August reports
are the first for this species in AZ between the months of March and
September. The only previous Iceland Gull record at the lake was 8 November
2017.
