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 Yosemite National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 192nd most-seen of the 227 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.
September and October
In those months about 10% of wildlife watchers report a Western Calligrapher in Yosemite National Park on a given day, against under 5% in November to August, the lowest months. Those are among Yosemite National Park's driest months, with about 35 mm of rain a month against 220 mm in January.
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 6
Of the 6 parks where we can rate Western Calligrapher sightings, Yosemite National Park ranks 5th at under 5%. The best odds are in Redwood National Park (United States, about 10%), Pacific Rim National Park Reserve (Canada, about 10%) and Channel Islands National Park (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 Yosemite National Park (5 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.
