Empidonax difficilis
Silhouette: Emily Willoughby · PhyloPic
In 3 days <5%
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 |
Rare
Under 5% of wildlife watchers report a Pacific-slope Flycatcher sighting in Denver on a given day, based on 453 verified sightings from GBIF citizen-science data. It is the 159th most-seen of the 299 birds we can rate there. Over three days the chance rises to under 5%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Pacific-slope Flycatcher in Denver on a given day, so our monthly data shows no clear season.
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.
17th of 21
Of the 21 cities where we can rate Pacific-slope Flycatcher sightings, Denver ranks 17th at under 5%. The best odds are in Tijuana (México, about 30%), Vancouver (Canada, about 10%) and San Diego (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Pacific-slope Flycatcher is recorded against all the birds logged in Denver (453 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.
