Giant Western Crane Fly

Giant Western Crane Fly

Holorusia hespera

Daily sighting probability <5% · Rare
at San Francisco

In 3 days ~10% in a week ~20%

70 Verified sightings at San Francisco
29 In all 2 parks From 2019 to 2026
September Best month
☀️🌙 Day & Night When it's spotted

About the Giant Western Crane Fly

Holorusia hespera, the giant western crane fly, is a species of crane fly in the family Tipulidae. It is found in western North America. H. hespera is the largest North American species of cranefly, with wings reaching lengths of 40 mm (1.6 in). The species is noted to lack wing interference patterning on the glossy amber colored wing surface, suggested to be a result of the wing thickness. The wing surfaces are textured with ridging and folds and the coloration is uniform across the wing. Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Sequoia and Kings Canyon National Parks 🇺🇸 United States
~10%
2 Yosemite National Park 🇺🇸 United States
~10%

Cities Where Found

# City Country Daily sighting probability
1 Seattle 🇺🇸 United States
<5%
2 Vancouver 🇨🇦 Canada
<5%
3 Portland 🇺🇸 United States
<5%
4 San Francisco 🇺🇸 United States
<5%
5 Los Angeles 🇺🇸 United States
<5%
6 San Diego 🇺🇸 United States
<5%

Before you go

What are the chances of seeing a Giant Western Crane Fly in San Francisco?

Rare

Under 5% of wildlife watchers report a Giant Western Crane Fly sighting in San Francisco on a given day, based on 70 verified sightings from GBIF citizen-science data. It is the 180th 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 20%, if each day is a fresh chance.

When is the best time to see a Giant Western Crane Fly in San Francisco?

Any time of year

In every month with enough records, under 5% of wildlife watchers report a Giant Western Crane Fly in San Francisco on a given day, so our monthly data shows no clear season.

What time of day is best to see a Giant Western Crane Fly?

Between 1 and 4 pm

Across all the parks we cover, that three-hour window holds the most Giant Western Crane Fly sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.

Is San Francisco the best place to see a Giant Western Crane Fly?

Among the best

Of the 6 cities where we can rate Giant Western Crane Fly sightings, San Francisco ranks 4th at under 5%, level with the leaders once rounded. The best odds are in Seattle (United States, under 5%), Vancouver (Canada, under 5%) and Portland (United States, under 5%).

Where does the Giant Western Crane Fly sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Giant Western Crane Fly is recorded against all the insects logged in San Francisco (70 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.

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