Rails at Ellis Creek - Virginia and Sora

Alerted in a post on NorthBayBirds (YahooGroups site), Patti and I went to the Ellis Creek Water Treatment ponds in Petaluma on September 12, 2015. Access there is off Cypress Drive, just a bit south of PRBO Conservation Science headquarters.

The northernmost pond (C) is currently being drained, mostly to control the bullfrog population. Hundreds of birds are attracted to wealth of prey, as the fish are concentrated in shallow puddles and the invertebrate rich mud is exposed like a giant buffet table. Hundreds of Dowitchers gathered, along with a host of herons, egrets, Wilson's Snipes and dabbling ducks. Best to go early (8-9am). Highlights for us were jaw-dropping frame-filling sights of Sora's (more than 10) and Virginia Rails at the northeast corner of the pond along the shoreline vegetation.

The Virginia Rail ( Rallus limicola) looks like a small version of a Ridgway's Rail (split from the Clapper Rail of the east and gulf coast). The dull leg color of this one may indicate a young rail transitioning to basic adult plumage. Note the downcurved bill, absence of white streaks on the back, minimal color in the bill, and soft gray face.

Another view shows how the fine tips of the bill are perfect for grasping tiny prey from the surface of the mud. Note the limited black and white barring on the flank patch over the legs, more sharply defined than the barred patch on a Ridgway's rail:

The Sora, Porzana carolina, is in a different rail genus. They have been breeding for years at Ellis Creek and the Las Gallinas ponds. The yellow bill, white edges on the back feathers and more extensive black and white barring on the flanks make for a certain identification. This is an adult in basic plumage. In winter the bill will be brighter yellow, and the black mask will be become larger.

​Another view shows how rails often cock their short tails upward. The 8.75" Sora is just a bit smaller than the 9.5" Virginia Rail. Both species prefer fresh water marshes. 

Sora - Porzana carolina

Birders who visit fresh water marshes will often hear the strange descending whinny call of the Sora, a small secretive rail that is usually tough to spot. An adult and a juvenile Sora were reported recently at Ellis Creek, Petaluma, at a location where they could be easily found and observed. The adult gave a loud whistled call as it foraged on the west side of pond "D".

Check out those large toes!

First shot shows the large toes typical of many marsh denizens. The yellow bill, is distinctive for the adult Sora. In this case the yellow bill is a bit dusky, which along with the minimal black in the face near the bill suggests it may be a female.

 Second shot gives a better look at the bill, as well as the pretty brown eye. Note the cocked-up tail, a frequent posture. You can just about see the white undertail coverts

Third shot shows it in the grass along the bank of the pond, where is foraged actively for seeds the entire time we watched. Often it was too close for me to frame a shot! By far our best ever look at this shy species.

The Sora is said to be our mostly common and widely distributed member of the rail family (around here I would bet on the Coot to win that distinction). They breed all across Canada in fresh water marshes that have cattails and other emergent vegetation. Most are migratory, despite their not being strong fliers. The genus Porzana has 14 species world-wide, with the other 13 sharing the common name "Crake".