Calidris mauri
Silhouette: Edwin Price · PhyloPic
In 3 days ~50% in a week ~80%
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 20% of wildlife watchers report a Western Sandpiper sighting in Isla del Coco National Park on a given day, based on 68 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 33rd most-seen of the 69 birds we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
September
In that month about 70% of wildlife watchers report a Western Sandpiper in Isla del Coco National Park on a given day, against under 5% in April and November, the lowest months. May and July–August have too few records to rate.
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.
3rd of 34
Of the 34 parks where we can rate Western Sandpiper sightings, Isla del Coco National Park ranks 3rd at about 20%. The best odds are in Pacific Rim National Park Reserve (Canada, about 30%) and El Vizcaíno Biosphere Reserve (Mexico, about 30%).
Same genus: Calidris
The closest relatives of the Western Sandpiper that you can see in Isla del Coco National Park (genus Calidris, Calidris Sandpipers) are Least Sandpiper (about 30%), Sanderling (about 30%) and Pectoral Sandpiper (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 Isla del Coco National Park (68 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.
