EA 110 – Field Ornithology – Class VII

(this is a back-dated post – I’m a bit behind on posting my class notes)

Today we started in on page 178 of the National Geographic Field Guide to North American Birds, beginning with…

Great Knot (GRKN):

• no California records, 1 fall Oregon record in Coos Bayy

Red Knot (REKN):

• black and orange buffy back in alternate plumage
• around the size and shape of a Dowitcher, but with a shorter bill and lacking the white back stripe in flight
• its orange belly extends onto its face in alternate plumage
• it’s an uncommon migrant and rare winter visitor to the SF Bay Area
• seen mostly along immediate coast on tidal mudflats
• April is the best time to see them here in alternate plumage – they’ve been observed in the past at Coyote Point
• have a relatively straight bill
• basic plumage is gray with a prominent white supercilium
• they wade deeper than many other shorebirds, up to their bellies
• juvenile has a white terminal band and black sub-terminal band on the scapulars
• they’re easy to overlook in basic and juvenile plumage, as they’re unremarkable and nondescript, similar to a Willet, but 1/2 their size
• often associate with Dowitchers
• forage primarily on receeding, not incoming, tides
• due to its short’ish bill, it feeds near the surface rather than probing deeply as do Dowitchers
• when foraging it bobs its head without raising it, unlike a Dowitcher
• are in a severe decline in the Eastern US due to a crash in the horseshoe crab population.  This is because REKN depend on eating horseshoe crab eggs, and horseshoe crabs are being extensively collected for scientific/medical research
• have a greyish white rump in flight
• have a thin white wing stripe
• yellowish/greenish legs

Sanderling (SAND):

 
Sanderling at Princeton-by-the-Sea

• have buffy head in alternate plumage
• juvenile is all-white underneath
• have large-looking eyes that stand out on their face
• are abundant on the SF area coast
• have a white face in basic plumage
• black legs
• have no rear toe, just 3 front toes, unlike other Calidris
• basic plumage ghostly pale above, pure white below
• ~same size as a Dunlin
• face is lighter than a Dunlin’s, which is more grey/brown above, and has a larger bill than does SAND
• Western Sandpiper (WESA)’s eyes look smaller since its face isn’t white
• it’s the only “peep” typically seen on sandy beaches “chasing” the waves in flocks.
• exhibit “clockwork toy” running to and fro, like a wind-up bird
• breed in the Arctic tundra and winter on most of the world’s coasts
• are one of the most widespread shorebirds worldwide
• similar Snowy Plover (SNPL) has a much shorter bill and a broken breast band, but SAND can be confused with SNPL if it’s a bid wind-blown and the bill is not visible
• in alternate plumage it can look a lot like a Red-necked Stint (RNST), so beware!
• can also be mistaken for Baird’s Sandpiper (BASA)
• has fairly bold wing stripes in flight

Dunlin (DUNL):

•  arctic breeder
• is a northern hemispheric bird
• is a common wintering shorebird in the SF Bay
• has reddish upper parts w/a large black belly patch in alternate plumage
• has a medium-length bill that droops at the end
• wades in shallow water, rather than in mud like WESA
• there is much geographic variation and quite a number of subspecies
• American subspecies used to be called the Red-backed Sandpiper
• juveniles stay on the breeding grounds through their first molt, so we in the SF area hardly ever see juvenile Dunlins (recall most other sandpiper juveniles leave the breeding grounds before their first molt, so we see them in juvenile plumage, and are followed 4-6 weeks later by adults)
• Rock Sandpiper (ROSA) also has a dark spot on its chest in alternate plumage, but it’s much smaller than a Dunlin’s
• in basic plumage, head is all-dark with a nceck band, and the eye doesn’t stand out
• has the longest bill of any “peep”
• in basic plumage, has plain upperparts and a faint light supercilium, with a contrasting demarcation between the darker upperparts and light underparts
• they’ve just recently arrived for the winter in the SF Bay Area, so keep an eye out for them
• can number in the 100,000s in SF Bay
• have a white wing stripe, white-edged tail w/dark center, like most Calidris

Curlew Sandpiper (CUSA):

• Eurasian bird, vagrant in North America
• most records are in the eastern US – they’re very rare on the west coast
• is a rare visitor to Alaska
• plumage similar to Red Knot (REKN), but bill is simliar to Dunlin’s
• there’s 1 record for SF, in Lake Merced
• are larger than WESA
• are long-winged, and have long primary projection
• bill is curved throughout its length, rather than at the tip like a DUNL
• DUNL has shorter legs than CUSA, especially the tibia (above the knees)
• has an all-white rump w/no darker center, unlike most Calidris sandpipers
• can be confused with Stilt Sandpipers (STSA), but CUSA has black legs vs. yellowish legs for STSA
• juveniles have buffy washed appearance
• have faint eye line

We concluded class with our usual quiz – I scored 12.5/20