Calidris mauri
Silhouette: Edwin Price · PhyloPic
In 3 days ~70% in a week ~90%
The western sandpiper (Calidris mauri) is a small migratory shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific mauri commemorates Italian botanist Ernesto Mauri (1791–1836).
This is one of the most abundant shorebird species in North America, with a population in the millions. Within the genus Calidris the western sandpiper is most closely related to the semipalmated sandpiper (Calidris pusilla).
Adults have dark legs and a short, thin, dark bill, thinner at the tip. The body is brown on top and white underneath. They are reddish-brown on the crown. This bird can be difficult to distinguish from other similar tiny shorebirds, especially the semipalmated sandpiper. This is particularly the case in winter plumage, when both species are plain grey. The western sandpiper acquires winter plumage much earlier in the autumn than the semipalmated sandpiper.
Measurements: Length: 14–17 cm (5.5–6.7 in) Wingspan: 35–37 cm (14–15 in) Weight: 22–35 g (0.78–1.23 oz) Their breeding habitat is tundra in eastern Siberia and Alaska. They nest on the ground usually under... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Panama City | 🇵🇦 Panama | |
| 2 | San Diego | 🇺🇸 United States | |
| 3 | San Francisco | 🇺🇸 United States | |
| 4 | Los Angeles | 🇺🇸 United States | |
| 5 | Havana | 🇨🇺 Cuba | |
| 6 | León | 🇲🇽 México | |
| 7 | Maracaibo | 🇻🇪 Venezuela | |
| 8 | Mesa | 🇺🇸 United States | |
| 9 | Portland | 🇺🇸 United States | |
| 10 | Seattle | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Monterey Bay Aquarium | 🇺🇸 United States |
Possible
About 30% of wildlife watchers report a Western Sandpiper sighting in Pacific Rim National Park Reserve on a given day, based on 1,126 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 17th most-seen of the 187 birds we can rate there. Over three days the chance rises to about 70%, and over a week to about 90%, if each day is a fresh chance.
May and August–September
In those months about 60% of wildlife watchers report a Western Sandpiper in Pacific Rim National Park Reserve on a given day, against under 5% in March, June and November, the lowest months. Those are among Pacific Rim National Park Reserve's driest months, with about 110 mm of rain a month against 470 mm in November.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Western Sandpiper sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 34 parks where we can rate Western Sandpiper sightings, Pacific Rim National Park Reserve has the highest daily chance: about 30%. Next come El Vizcaíno Biosphere Reserve (Mexico, about 30%) and Isla del Coco National Park (Costa Rica, about 20%).
Same genus: Calidris
The closest relatives of the Western Sandpiper that you can see in Pacific Rim National Park Reserve (genus Calidris, Calidris Sandpipers) are Least Sandpiper (about 20%), Sanderling (about 20%) and Dunlin (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Western Sandpiper is recorded against all the birds logged in Pacific Rim National Park Reserve (1,126 verified sightings from 2019 to 2026), 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.
