Tabanus atratus
In 3 days ~20% in a week ~40%
Tabanus is a genus of biting horseflies of the family Tabanidae. Females have scissor-like mouthparts that are able to penetrate the skin of livestock animals. The horsefly can then extract and ingest the animal's blood. Horseflies of this genus are known to be potential vectors of anthrax, worms and trypanosomes. Some species, such as Tabanus bovinus, prefer bovine animals and are less harmful to humans. The genus contains hundreds of species and many species groups. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Padre Island National Seashore | 🇺🇸 United States | |
| 2 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 3 | Big Cypress National Preserve | 🇺🇸 United States | |
| 4 | Everglades National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Baltimore | 🇺🇸 United States | |
| 2 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 3 | Houston | 🇺🇸 United States | |
| 4 | Washington | 🇺🇸 United States | |
| 5 | Montreal | 🇨🇦 Canada | |
| 6 | Austin | 🇺🇸 United States | |
| 7 | Dallas | 🇺🇸 United States | |
| 8 | Chicago | 🇺🇸 United States | |
| 9 | Toronto | 🇨🇦 Canada | |
| 10 | Philadelphia | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Black Horse Fly sighting in Big Cypress National Preserve on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 193rd most-seen of the 262 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.
July
In that month about 30% of wildlife watchers report a Black Horse Fly in Big Cypress National Preserve on a given day, against under 5% in April–June and October–February, the lowest months. That is one of Big Cypress National Preserve's wettest months, with about 210 mm of rain against 40 mm in March.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Black Horse Fly sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 4
Of the 4 parks where we can rate Black Horse Fly sightings, Big Cypress National Preserve ranks 3rd at about 10%. The best odds are in Padre Island National Seashore (United States, about 20%) and Merritt Island National Wildlife Refuge (United States, about 10%).
Same family: Tabanidae
The closest relatives of the Black Horse Fly that you can see in Big Cypress National Preserve (family Tabanidae, Horse and Deer Flies) are Green Horse Fly (about 10%) and Yellow Fly Of The Dismal Swamp (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Black Horse Fly is recorded against all the insects logged in Big Cypress National Preserve (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.
