Rallus obsoletus
Silhouette: Ferran Sayol · PhyloPic
In 3 days ~10% in a week ~30%
Ridgway's rail (Rallus obsoletus) is a species of bird found principally along the Pacific coast of North America from the San Francisco Bay Area to southern Baja California, as well as in some regions of the Gulf of California. A member of the rail family, Rallidae, it is a large cinnamon-brown rail that lives in brackish tidal marshes and rarely flies. Its name commemorates American ornithologist Robert Ridgway.
This species is closely related to the clapper rail, and until recently was considered a subspecies. It has a long, downward curving bill and is grayish brown with a pale chestnut breast and conspicuous whitish rump patch. It is most active nocturnally and crepuscularly.
Typically cinnamon-brown in color, it is darker in coloration on the back. Adult coloration is variable, with several color morphs. The total length in adults is 32–41 cm (13–16 in), and weight ranges 160–470 g (5.6–16.6 oz). Males are about 20% larger than females. Size can vary by geographical location. Hatchlings are covered in black downy feathers.
Ridgway's rail forages along the ecotone between mudflat and higher vegetated zones and in tidal sloughs. Mussels, clams, arthropods... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | El Vizcaíno Biosphere Reserve | 🇲🇽 Mexico |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Diego | 🇺🇸 United States | |
| 2 | San Francisco | 🇺🇸 United States | |
| 3 | Los Angeles | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Ridgway's Rail sighting in San Francisco on a given day, based on 4,106 verified sightings from GBIF citizen-science data. It is the 134th most-seen of the 375 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
November to January
In those months about 10% of wildlife watchers report a Ridgway's Rail in San Francisco on a given day, against under 5% in February to October, the lowest months. Those are among San Francisco's wettest months, with about 85 mm of rain a month against almost none in July.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Ridgway's Rail sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 3
Of the 3 cities where we can rate Ridgway's Rail sightings, San Francisco ranks 2nd at under 5%. The best odds are in San Diego (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Ridgway's Rail is recorded against all the birds logged in San Francisco (4,106 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
