EA 110 – Field Ornithology – Class 4

Another fun- and fact-filled class last night. Joe talked about the carniverous River Otters inhabiting Rodeo Lagoon (see my post about our field trip for more on this). 3 species not seen on previous class trips (for the last 20 or so years) to the lagoon were noted: Common Tern, Blackpoll Warbler and Black-bellied Plover.

 
Long-billed Curlew at Palo Alto Baylands Park

• Foggy, drizzly days are good for migrant-watching, since they won’t migrate in inclement weather, dropping down to shelter & forage.

• The SF Rare Bird Roundup was last weeken. Joe birded Lake Merced, but found no rarities. Interesting, but not rare, birds he saw included Ring-necked Pheasant, many Red-necked Phalaropes, and Eurasian Collared Doves (which are often visible on the telephone wires on the west side of the concrete bridge at Lake Merced’s south end).

• Joe recommended joining the ABA (note to self). The latest “Birding” mag is now out

From the photo of a strange Red-winged Blackbird with white patches gracing the cover of “Birding,” Joe talked about abnormal pigment nomenclature.

• Leucistic (loo-kiss-tic): usually used to describe a bird with dilute color, but otherwise normal patterning
• Partial albino: pigment missing in some, but not all, feathers. Geneticists dislike this term, as albinism is a genetic condition and, like pregnancy, is an all-or-nothing proposition. It’s not very useful to restrict its use thusly, however, since true albino birds are very rare, and generally don’t survive long at all.
• The current issue of “Birding” proposes a new terminology, which Joe doesn’t care for, as it’s complicated, and there are too many new terms for anyone to keep straight, and many of them sound similar when spoken in the field (amelanistic, hypermelanistic, hypomelanistic, and so on)

We picked up on pg. 170 of the National Geographic bird guide.

Curlews:

• called due to the sound of their call, not because of any “curling” in their bills (although they have that too)

Little Curlew (LICU):

• breeds in N & E Siberia in the interior
• is not a well-known bird, as its usual locale is very remote
• it’s one of the smallest (surviving) curlews
• winters in Australia
• is quite rare in California, with just a couple of records
• one was seen near Santa Maria, California, found by a birder who was looking for a reported Curlew Sandpiper
  • This bird was seen in a farm field, and an obliging farmer allowed birders access during the 2 weeks it was present. His guestbook logged hundreds of birders from all over the country.
• resembles the probably-extinct Eskimo Curlew
• has pale lores and a black stripe behind the eye
• is smaller and with a less strongly-patterned face than the similar Whimbrel

Eskimo Curlew (ESCU):

• In all likelihood, is extinct due to market hunting after the Civil War. Even by 1900 it was a rare bird. The last accepted record of one was in Texas in 1963
• had a black line extending through the eye
• had chevron-shaped markings on its flank
• there are continued undocumented and unconfirmed reports of them from time to time.

Whimbrel (WHIM):

• North American subspecies is darker than the EurAsian subspecies
  • these used to be separate species, with the NA Whimbrel called the “Hudsonian Curlew”
• are mottled brown
• have a pronounced stripe pattern on their head with lateral stripes and a pair of black crown stripes
• are fairly common along the California coast on rocky shores, tidal mudflats and so on
• are uncommon in the interior
• have a distinct hollow whistling call
• the shape & length of their bill is very variable, with females having longer bills, males shorter, and juveniles shorter yet. Length overlaps quite a bit with Long-billed Curlew except at the extremes
• runt WHIM have been confused with Little and Eskimo Curlews
• some, but not all, have a pink-based lower mandible
• plumages are all pretty similar
• other than the Siberian ssp., they have a dark rump when flying
• have brown barring on the underwing coverts

Bristle-thighed Curlew (BTCU):

• breeds in Western Alaska, winters in Polynesia
• similiar to Whimbrel
• can be found in Gnome, Alaska
• has a less barred, plain cinnamon rump compared to Whimbrel
• Coarser and darker markings overall than Whimbrel
• has bristles on its thighs, but this alone isn’t enough for an ID
• call is a plover-like slurred whistle
• there are a few California records of BTCU, one in Crescent City, one in Point Reyes
• are seen as migrants in Hawaii
• worldwide population is very small, ~1500 individuals
• may have a longer bill than Whimbrel

Long-billed Curlew (LBCU):

 
Long-billed Curlew at Palo Alto Baylands Park

• more common in the interior than along the coast
• likes flooded farmlands, tidal mudflats, etc
• is one of the largest shorebirds in the world
• bill length is quite variable
• has a faint eye stripe
• whole bird is cinnamon-colored, plumage very similar to Marbled Godwit
• Marbled Godwit & LBCU are very difficult to tell apart when they’re asleep, as they tuck their bills into their back.
• LBCU may have lighter grey legs compared to Marbled Godwit’s black legs
• plumage is largely the same all year
• probe deep into mud for shrimp and snails
• withdraw their neck in flight (compare to flying White-faced Ibis, which extends its neck in flight and has its feet trailing its tail)
• call is “Curlee”
• breeds in the Great Basin area, not the arctic

Far-eastern Curlew (FECU):

• winters in Australia, breeds in Siberia
• 1 Washington state record, no California records
• similar in size to the Eurasian Curlew, but has a dark rump, and might be seen in the western US, whereas the Eurasian Curlew, if seen, would be in the east.
• much more black-and-white vs. the buffy plumage of LBCU

This wrapped up Numenis and we finished class with a slide ID quiz, which I did much better on than I did on the Tringa quiz last week (I got 17/20 correct – it helps that Curlews are more distinct than Tringa birds!)