migration in the last week at the Cosumnes River Preserve

Glennah Trochet

Dear Birders,

Last Sunday I did the monthly Lost Slough bird survey at the Cosumnes River Preserve in southern Sacramento County.  I tallied 80 species on the managed wetlands west of Franklin Boulevard and in the trees and brush on their southern and western perimeter.  Migrants and lingerers of modest interest were these:
greater white-fronted goose-  7
blue-winged teal-  3
northern pintail-  1
ruddy duck-  1
black-necked stilt-  34
American avocet-  21
killdeer-  14
semipalmated plover-  26
whimbrel-  1
dunlin-  9
least sandpiper-  45
western sandpiper-  230
peep sp.-  35
long-billed dowitcher-  210
greater yellowlegs-  4
American white pelican-  12
American pipit-  2
golden-crowned sparrow-  1
Savannah sparrow-  2
Lincoln's sparrow-  1
Bullock's oriole-  8
orange-crowned warbler-  2
common yellowthroat-  8
Audubon's warbler-  1
Wilson's warbler-  11
western tanager-  1
black-headed grosbeak-  3
lazuli bunting-  1

Andrew Lee was out there the same morning, and he had both snowy plover and short-billed dowitcher, species I missed.

On Monday the 3rd, I visited only the parcels that had promise as shorebird areas: Lost Slough, Desmond Road, the TNC Barn ponds, the flooded rice fields north of the equipment pad (zero shorebirds here) and the Twin Cities Unit.  There were far fewer waterfowl than on the preceding day.  Here's the tally of what most interested me:
greater white-fronted goose-  12
blue-winged teal-  2
ring-necked duck-  2
ruddy duck-  1
eared grebe-  3
black-necked stilt-  18
American avocet-  20
killdeer-  20
semipalmated plover-  44
snowy plover-  1
dunlin-  11
least sandpiper-  60
western sandpiper-  410
peep sp.-  80
long-billed dowitcher-  450
Wilson's snipe-  1
greater yellowlegs-  2
red-necked phalarope-  3
Caspian tern-  4
peregrine falcon-  1
American pipit-  38
golden-crowned sparrow-  1
Savannah sparrow-  8

Tuesday I made a fairly wide-ranging visit, starting behind the Farm Center gate with a sort-of Tall Forest survey tour and ending by looking for shorebirds.  During the latter I noticed that an adult bald eagle put up numbers of shorebirds in the northwestern part of Lost Slough East, so there was a pond that I was previously ignorant of.  That pond was the best spot for shorebirds this day.  This day's highlights:
blue-winged teal-  2
ring-necked duck-  1
black-necked stilt-  57
American avocet-  16
black-bellied plover-  2
killdeer-  25
semipalmated plover-  75
snowy plover-  1
dunlin-  26
least sandpiper-  310
western sandpiper-  750
peep sp.-  350
long-billed dowitcher-  770
spotted sandpiper-  1 (FOS)
solitary sandpiper-  1
greater yellowlegs-  8
Wilson's phalarope-  1 (FOS)
red-necked phalarope-  2
bald eagle-  1 adult
ash-throated flycatcher-  18
western wood-pewee-  3 (FOS)
Hammond's flycatcher-  1 ((FOS; earlier sightings were of a wintering bird)
western flycatcher-  2 (both silent)
Empidonax sp.-  2
Cassin's vireo-  1
warbling vireo-  10
yellow-billed magpie-  1
Swainson's thrush-  2 (FOS)
American pipit-  36 (same flock at the barn ponds as yesterday)
Oregon junco-  2 (both appeared to be males)
white-crowned sparrow-  1
golden-crowned sparrow-  7
Zonotrichia sp.-  3
Savannah sparrow-  1
Bullock's oriole-  15
orange-crowned warbler-  3
Nashville warbler-  1 (singing atypical song)
common yellowthroat-  6
yellow warbler-  1
Townsend's warbler-  1
hermit warbler-  2 (FOS)
Wilson's warbler-  10
western tanager-  5
black-headed grosbeak-  25
blue grosbeak-  1 (FOS)

Along Wood Duck Slough I saw another bobcat (quite possibly a repeat observation of one seen there about ten days ago).  The north wind made my vehicle quiet enough by comparison that I was able to slowly advance on the cat from about 100 meters to about 30 before it heard me and bolted off the road.  I had a west coast lady today, the first lady identified to species this year.

On the morning of Cinco de Mayo, I got up at 03:30 so as to take in the eta Aquarid meteor shower.  I saw zero meteors, a big disappointment.  But even at 4AM the tree swallows were chortling up a storm.  Do they even sleep?  On the plus side, I enjoyed looking once more at Jupiter, Saturn and Mars through the scope.  And for my first time, I saw the (one of several? I don't know) StarLink satellite chain pass overhead.  It seemed very low, but if it was reflecting sunlight at 04:40, then the satellites had to have decent elevation.  They took about five minutes to pass over and nearly spanned the sky, moving from west to east.  Watching the ground fog materialize out of clear air is always fun, too.  The visit was much like yesterday's, but with far fewer woodland migrants and, excepting dowitchers, few shorebirds, too:
greater white-fronted goose-  6
ring-necked duck-  1
hooded merganser-  1
black-chinned hummingbird-  1
black-necked stilt-  18
American avocet-  12 (two possible nests)
killdeer-  20
semipalmated plover-  40
snowy plover-  unable to find, presumed gone
whimbrel-  2
dunlin-  28
least sandpiper-  70
western sandpiper-  350
peep sp.-  300
long-billed dowitcher-  1150
spotted sandpiper-  1
Caspian tern-  4
bald eagle-  2, one adult and one large young seen in the nest
acorn woodpecker-  2
western wood-pewee-  4
Pacific-slope flycatcher-  1
warbling vireo-  1
Swainson's thrush-  1
hermit thrush-  1 (perhaps the least expected bird today)
American pipit-  7
no lingering sparrows
common yellowthroat-  4
yellow warbler-  1
Wilson's warbler-  2
western tanager-  2
lazuli bunting-  5, all males in a tight flock on the equipment pad

On Thursday the 6th, making a late start, I visited the fast-disappearing shorebird habitat, which is being replaced (sort of) by the very early planting of organic rice behind the Farm Center gate.  I ran into Andrew Lee again, who told me that there had been many more shorebirds earlier but nothing unusual.  My tally for this visit:
ring-necked duck-  1
black-necked stilt-  13
American avocet-  9
killdeer-  20
semipalmated plover - 32
whimbrel-  1
dunlin-  15
least sandpiper-  55
western sandpiper-  180
peep sp.-  110
long-billed dowitcher-  350
greater yellowlegs-  2
Caspian tern-  4 (one pair copulating at Lost Slough)

On Friday I elected to do the monthly Tall Forest bird survey owing to the windy weather forecast for this weekend and because of a scheduling conflict next weekend.  It was surprisingly cool (37 degrees F.) just before sunrise.  I found 81 species, with a poor showing of waterbirds on the rice so far.  These were the highlights:
hooded merganser-  1
long-billed dowitcher-  35
bald eagle-  2 (large nestlings)
acorn woodpecker-  1
olive-sided flycatcher-  1 (FOS)
western wood-pewee-  10
western flycatcher-  2
warbling vireo-  15
yellow-billed magpie-  1
common raven-  4
Swainson's thrush-  13
golden-crowned sparrow-  1
yellow-breasted chat-  1 (FOS)
brown-headed cowbird-  40 (the lowlight)
orange-crowned warbler-  1
Nashville warbler-  2
MacGillivray's warbler-  2 (FOS)
common yellowthroat-  12
yellow warbler-  8
black-throated gray warbler-  1
Townsend's warbler-  5
hermit warbler-  2
Wilson's warbler-  14
western tanager-  5
blue grosbeak-  1
lazuli bunting-  2

I had a decent day with mammals, too: a bat sp., MicrotusMus (probably), CastorSciurus nigerSylvilagusMephitisLontraProcyonFelis catusCanis latransCanis familiaris (one of the tractor operators was throwing a stick into a ditch for his dog to retrieve), and Odocoileus.

The coyote possibly found a harrier nest.  A male harrier was repeatedly diving on a coyote east of the Tall Forest.  I couldn't see initially what was drawing the bird's focus, but after a short time, the coyote jumped up several times in an attempt to nab the annoying bird.  This went on for about 15 minutes.  I gave up before the show was over.

In yesterday's howling winds I gave the forest blocks a miss.  So I contented myself with another shorebird-oriented visit.  The variety wasn't bad, though the numbers were rather poor:
ring-necked duck-  1
black-necked stilt-  5
American avocet-  12
killdeer-  30
semipalmated plover-  12
dunlin-  10
least sandpiper-  7
western sandpiper-  185
peep sp.-  35
long-billed dowitcher-  139
spotted sandpiper-  3
greater yellowlegs-  4
Wilson's phalarope-  1
red-necked phalarope-  3

Today I did something very like Tuesday's wide-ranging visit.  I started behind the gate.  I didn't play a recording, but no magpie stirred while I was at the shack before dawn.  The low near the Accidental Forest was 56 degrees F.  Friday's chat was still singing in the same spot (presumed to be the same bird), and another was along Wood Duck Slough.  I checked for yellow warbler from the north end of the Accidental Forest to south breach and the nice patch on the west side of the bottoms.  I found as many along the ditch margins I walked as I did where they concentrated along the river last year.  The wind didn't help the birding in the trees.  The shorebird habitat is just about gone, excepting the few rice fields that have had water long enough to grow some invertebrates.  Today's highlights:
blue-winged teal-  2
black-necked stilt-  2
American avocet-  8
killdeer-  9
semipalmated plover-  13
dunlin-  1
western sandpiper-  101
long-billed dowitcher-  152
spotted sandpiper-  1
red-necked phalarope-  3
Caspian tern-  2
western wood-pewee-  5
Pacific-slope flycatcher-  1
Cassin's vireo-  1
warbling vireo-  12
Swainson's thrush-  12
yellow-breasted chat-  2
common yellowthroat-  5
yellow warbler-  9
Townsend's warbler-  2
Wilson's warbler-  17
western tanager-  3
blue grosbeak-  2

It looks like the breeding last year of chipping sparrows near the Tall Forest was a one-off.  I didn't expect otherwise.  I was more hopeful that the "colony" of yellow warblers in and near the Accidental Forest last year would see a reprise this season.  So far, only two males are singing like they have some attachment to a piece of woodland there.

I am hopeful that docent-led activities at the preserve will resume soon.  I look forward to showing folks the Tall Forest and vicinity again.

John Trochet