Pogonortalis doclea
In 3 days ~20% in a week ~30%
Pogonortalis doclea, the boatman fly, is a species of signal fly (family Platystomatidae). It is native to Australia and has been introduced to California in the United States. Characteristics of P. doclea are: the cheek immediately below the eye being less than a tenth the height of the eye; the hind femur having an anteroventral keel at the distal third; and the anterior crossvein of the wing meeting vein 4 before the mid-length of the discal cell.
P. doclea is sexually dimorphic. Males have a bundle of long curved bristles on each cheek of the head. In this location, females have a single shorter bristle among small hairs. Larger males also have the head ventrally widened.
This species waves its wings like the rowing of oars on a boat, thus the common name "boatman fly". A slow approach to other flies with the wings held at a depressed slant, extended forwards, indicated cautious investigation.
Pogonortalis doclea is commonly found in Australian gardens. Adults are attracted to and feed on the fresh dung of mammals. Males are territorial, engaging in face-to-face pushing contests, using the bundle of long, curved bristles on either cheek. In such... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Blue Mountains National Park | 🇦🇺 Australia | |
| 2 | Springbrook National Park | 🇦🇺 Australia | |
| 3 | Lamington National Park | 🇦🇺 Australia |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Melbourne | 🇦🇺 Australia | |
| 2 | Sydney | 🇦🇺 Australia | |
| 3 | Brisbane | 🇦🇺 Australia | |
| 4 | Perth | 🇦🇺 Australia | |
| 5 | Los Angeles | 🇺🇸 United States | |
| 6 | San Diego | 🇺🇸 United States | |
| 7 | San Francisco | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Boatman Fly sighting in Perth on a given day, based on 18 verified sightings from GBIF citizen-science data. It is the 123rd most-seen of the 275 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.
May to October
In those months about 10% of wildlife watchers report a Boatman Fly in Perth on a given day, against under 5% in November to April, the lowest months. Those are among Perth's wettest months, with about 90 mm of rain a month against 10 mm in December.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Boatman 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 7 cities where we can rate Boatman Fly sightings, Perth ranks 4th at about 10%, level with the leaders once rounded. The best odds are in Melbourne (Australia, about 10%), Sydney (Australia, about 10%) and Brisbane (Australia, about 10%).
Same order: Diptera
The closest relatives of the Boatman Fly that you can see in Perth (order Diptera, Flies) are Yellow-Shouldered Stout Hover Fly (about 10%), Australian Tiger Crane Fly (about 10%) and Bathroom Moth Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Boatman Fly is recorded against all the insects logged in Perth (18 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.
