Eristalis hirta
In 3 days ~20% in a week ~30%
Eristalis hirta, the black-footed drone fly, is a common Western North American species of syrphid fly, first officially described by Loew in 1866. Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies as they are commonly found on and around flowers, from which they get both energy-giving nectar and protein-rich pollen. The larvae are aquatic filter-feeders of the rat-tailed type.
This species is found in Western North America and Northern Europe in raised bogs, ditches and temporary pools. For terms see Morphology of Diptera Size Length: 10–15 mm (0.39–0.59 in) Head The frons are a shiny black with light brownish yellow pile. The face and frons of female is unusually broad. The pile of the face is light brownish yellow except the facial stripe (tubercle) and the cheeks which are a shiny black. The antennae are very dark brownish black. The arista is slightly plumose basally. The eyes are contiguous only in males.
Thorax The thorax is dark, shiny, brownish black with yellowish pile. The scutellum is lighter Brownish and shiny. The pleurae are covered with pale yellow... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 2 | Pacific Rim National Park Reserve | 🇨🇦 Canada | |
| 3 | Grand Teton National Park | 🇺🇸 United States | |
| 4 | Yellowstone National Park | 🇺🇸 United States | |
| 5 | Rocky Mountain National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sacramento | 🇺🇸 United States | |
| 2 | San Francisco | 🇺🇸 United States | |
| 3 | Vancouver | 🇨🇦 Canada | |
| 4 | Portland | 🇺🇸 United States | |
| 5 | Seattle | 🇺🇸 United States | |
| 6 | Los Angeles | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Black-Footed Drone Fly sighting in Grand Teton National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 119th most-seen of the 140 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.
September and October
In those months about 10% of wildlife watchers report a Black-Footed Drone Fly in Grand Teton National Park on a given day, against under 5% in November to August, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Black-Footed Drone Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 parks where we can rate Black-Footed Drone Fly sightings, Grand Teton National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Sequoia and Kings Canyon National Parks (United States, about 10%) and Pacific Rim National Park Reserve (Canada, about 10%).
GBIF citizen-science records
It is estimated from how often the Black-Footed Drone Fly is recorded against all the insects logged in Grand Teton National Park (6 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.
