Empidonax difficilis
Silhouette: Emily Willoughby · PhyloPic
In 3 days ~50% in a week ~80%
The western flycatcher (Empidonax difficilis) is a small insectivorous bird in the family Tyrannidae. It is native to western North America, where it breeds in the Rocky Mountains and Pacific Coast forests and mountain ranges from California to Alaska and south to central Mexico; northern populations migrate south to Mexico for the winter.
The western flycatcher was recognized as a single species until 1989, when the American Ornithologists' Union split it into two different species: the Pacific-slope flycatcher (E. difficilis) of coastal western North America and parts of the western Rocky Mountains, and the Cordilleran flycatcher (E. occidentalis) of the interior Rocky Mountains, with both species wintering in Mexico. Both species looked virtually identical to one another, with the split being based on differing breeding habitats and apparent differences in songs and calls. The split was recognized until 2023, when the American Ornithologists' Union and International Ornithological Congress again lumped both species due to a lack of consistent vocal, genetic, morphological differences and extensive hybridization across much of their range.
There are... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Tijuana | 🇲🇽 México | |
| 2 | Vancouver | 🇨🇦 Canada | |
| 3 | San Diego | 🇺🇸 United States | |
| 4 | Toluca | 🇲🇽 México | |
| 5 | Los Angeles | 🇺🇸 United States | |
| 6 | San Francisco | 🇺🇸 United States | |
| 7 | Seattle | 🇺🇸 United States | |
| 8 | Guadalajara | 🇲🇽 México | |
| 9 | Portland | 🇺🇸 United States | |
| 10 | Mexico City | 🇲🇽 México |
Possible
About 20% of wildlife watchers report a Pacific-slope Flycatcher sighting in Yosemite National Park on a given day, based on 761 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 33rd most-seen of the 169 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.
May
In that month about 40% of wildlife watchers report a Pacific-slope Flycatcher in Yosemite National Park on a given day, against under 5% in March and September–December, the lowest months. That is one of Yosemite National Park's driest months, with about 50 mm of rain against 220 mm in January.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Pacific-slope Flycatcher sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 25 parks where we can rate Pacific-slope Flycatcher sightings, Yosemite National Park ranks 4th at about 20%, level with the leaders once rounded. The best odds are in Redwood National Park (United States, about 20%), Pacific Rim National Park Reserve (Canada, about 20%) and Olympic National Park (United States, about 20%).
Same genus: Empidonax
The closest relatives of the Pacific-slope Flycatcher that you can see in Yosemite National Park (genus Empidonax, Empidonax Flycatchers) are Dusky Flycatcher (about 20%) and Hammond's Flycatcher (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Pacific-slope Flycatcher is recorded against all the birds logged in Yosemite National Park (761 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.
