Eupeodes volucris
In 3 days ~20% in a week ~30%
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 Rocky Mountain National Park on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 110th most-seen of the 191 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
June–July and September–October
In those months about 10% of wildlife watchers report a Large-Tailed Aphideater in Rocky Mountain National Park on a given day, against under 5% in August and November–May, the lowest months.
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.
7th of 8
Of the 8 parks where we can rate Large-Tailed Aphideater sightings, Rocky Mountain National Park ranks 7th at about 10%. The best odds are in Death Valley National Park (United States, about 20%), Joshua Tree National Park (United States, about 10%) and Channel Islands National Park (United States, about 10%).
Same family: Syrphidae
The closest relatives of the Large-Tailed Aphideater that you can see in Rocky Mountain National Park (family Syrphidae, Hover Flies) are Spot-Winged Pond Fly (about 10%), Common Loopwing Aphideater (about 10%) and Common Drone Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Large-Tailed Aphideater is recorded against all the insects logged in Rocky Mountain National Park (11 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.
