Empidonax traillii
Silhouette: Emily Willoughby · PhyloPic
In 3 days <5% in a week ~10%
The willow flycatcher (Empidonax traillii) is a small insect-eating, migrant bird of the tyrant flycatcher family native to North America. The willow flycatcher was included by the Franco-American ornithologist John James Audubon in his book The Birds of America based on a specimen collected in the "woods along the prairie banks of the Arkansas River". The section of the book containing the willow flycatcher was published in 1828. There are two variants of the plate illustrating the flycatcher. On one the binomial name is given as Muscicapa trailli and on the other as Muscicapa traillii. The latter spelling was used in 1831 by Audubon when describing the species in his Ornithological Biography that was published to accompany the plates and is now the accepted spelling. The specific epithet was chosen by Audubon to honour his friend the Scottish physician and zoologist Thomas Stewart Traill. The willow flycatcher is now one of 14 species placed in the genus Empidonax that was introduced in 1855 by the German ornithologist Jean Cabanis.
There are four subspecies recognized, all of which breed in North America (including three subspecies that breed in California). At one... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Vancouver | 🇨🇦 Canada | |
| 2 | Seattle | 🇺🇸 United States | |
| 3 | Chicago | 🇺🇸 United States | |
| 4 | New York City | 🇺🇸 United States | |
| 5 | Portland | 🇺🇸 United States | |
| 6 | Toronto | 🇨🇦 Canada | |
| 7 | Baltimore | 🇺🇸 United States | |
| 8 | Boston | 🇺🇸 United States | |
| 9 | Philadelphia | 🇺🇸 United States | |
| 10 | San Pedro Sula | 🇭🇳 Honduras |
Rare
Under 5% of wildlife watchers report a Willow Flycatcher sighting in San Francisco on a given day, based on 819 verified sightings from GBIF citizen-science data. It is the 205th most-seen of the 375 birds we can rate there. Over three days the chance rises to under 5%, and over a week to about 10%, if each day is a fresh chance.
September
In that month about 10% of wildlife watchers report a Willow Flycatcher in San Francisco on a given day, against under 5% in October to August, the lowest months. That is one of San Francisco's driest months, with almost no rain against 110 mm in December.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Willow 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.
15th of 30
Of the 30 cities where we can rate Willow Flycatcher sightings, San Francisco ranks 15th at under 5%. The best odds are in Vancouver (Canada, about 10%), Seattle (United States, under 5%) and Chicago (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Willow Flycatcher is recorded against all the birds logged in San Francisco (819 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.
