Eupeodes volucris
In 3 days ~20% in a week ~40%
Eupeodes volucris, the large-tailed aphideater or bird hover fly, is a species of hover fly in the family Syrphidae. As its "aphideater" name implies, larvae prey on plant-sucking insects, primarily aphids. The "hover" part of the family name derives from the fact that adults often hover over the plants they visit. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Death Valley National Park | 🇺🇸 United States | |
| 2 | Joshua Tree National Park | 🇺🇸 United States | |
| 3 | Channel Islands National Park | 🇺🇸 United States | |
| 4 | Grand Canyon National Park | 🇺🇸 United States | |
| 5 | Saguaro National Park | 🇺🇸 United States | |
| 6 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 7 | Rocky Mountain National Park | 🇺🇸 United States | |
| 8 | Yellowstone National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sacramento | 🇺🇸 United States | |
| 2 | Salt Lake City | 🇺🇸 United States | |
| 3 | Ciudad Juárez | 🇲🇽 México | |
| 4 | Denver | 🇺🇸 United States | |
| 5 | Phoenix | 🇺🇸 United States | |
| 6 | Mesa | 🇺🇸 United States | |
| 7 | San Diego | 🇺🇸 United States | |
| 8 | Los Angeles | 🇺🇸 United States | |
| 9 | Portland | 🇺🇸 United States | |
| 10 | San Francisco | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Large-Tailed Aphideater sighting in Portland on a given day, based on 63 verified sightings from GBIF citizen-science data. It is the 100th most-seen of the 507 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
April to July
In those months about 10% of wildlife watchers report a Large-Tailed Aphideater in Portland on a given day, against under 5% in August to March, the lowest months. Those are among Portland's driest months, with about 65 mm of rain a month against 250 mm in December.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Large-Tailed Aphideater 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 21 cities where we can rate Large-Tailed Aphideater sightings, Portland ranks 9th at about 10%, level with the leaders once rounded. The best odds are in Sacramento (United States, about 10%), Salt Lake City (United States, about 10%) and Ciudad Juárez (México, about 10%).
GBIF citizen-science records
It is estimated from how often the Large-Tailed Aphideater is recorded against all the insects logged in Portland (63 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.
