Toxomerus occidentalis
In 3 days ~10% in a week ~30%
Toxomerus occidentalis (Curran,1922) the Western Calligrapher, is a common species of syrphid fly found in western North America from British Columbia south to California, Colorado and Texas. Syrphid flies are also known as Hover Flies or Flower Flies because the adults are frequently found hovering around flowers from which they feed on nectar and pollen. Adults look very similar to the Eastern Calligrapher.The larvae are predators of a variety of aphids and mites. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Redwood National Park | 🇺🇸 United States | |
| 2 | Pacific Rim National Park Reserve | 🇨🇦 Canada | |
| 3 | Channel Islands National Park | 🇺🇸 United States | |
| 4 | Great Bear Rainforest | 🇨🇦 Canada | |
| 5 | Yosemite National Park | 🇺🇸 United States | |
| 6 | Olympic National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sacramento | 🇺🇸 United States | |
| 2 | Vancouver | 🇨🇦 Canada | |
| 3 | Portland | 🇺🇸 United States | |
| 4 | Seattle | 🇺🇸 United States | |
| 5 | San Francisco | 🇺🇸 United States | |
| 6 | San Diego | 🇺🇸 United States | |
| 7 | Los Angeles | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Western Calligrapher sighting in San Francisco on a given day, based on 165 verified sightings from GBIF citizen-science data. It is the 113th most-seen of the 737 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
August and September
In those months about 10% of wildlife watchers report a Western Calligrapher in San Francisco on a given day, against under 5% in October to July, the lowest months. Those are among San Francisco's driest months, with almost no rain against 110 mm in December.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Western Calligrapher sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
5th of 7
Of the 7 cities where we can rate Western Calligrapher sightings, San Francisco ranks 5th at under 5%. The best odds are in Sacramento (United States, about 10%), Vancouver (Canada, about 10%) and Portland (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Western Calligrapher is recorded against all the insects logged in San Francisco (165 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.
