Glaucopsyche lygdamus
In 3 days ~10% in a week ~20%
Glaucopsyche lygdamus, the silvery blue, is a small butterfly native to North America. Its upperside is a light blue in males and a dull grayish blue in females. The underside is gray with a single row of round spots of differing sizes depending upon the region.
G. lygdamus is found over much of the western United States and most of Canada extending north excepting most of Nunavut and the high Arctic islands. Wingspan is from 18 to 28 mm. It occurs in a variety of habitats including alpine meadows, shale barrens, dunes, and wooded areas. It feeds on Lupinus plants.
The extinct Xerces blue (Glaucopsyche xerces) was once thought to be a subspecies of the silvery blue. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Elk Island National Park | 🇨🇦 Canada | |
| 2 | Kluane National Park | 🇨🇦 Canada | |
| 3 | Riding Mountain National Park | 🇨🇦 Canada | |
| 4 | Jasper National Park | 🇨🇦 Canada | |
| 5 | Gros Morne National Park | 🇨🇦 Canada | |
| 6 | Banff National Park | 🇨🇦 Canada | |
| 7 | Grand Teton National Park | 🇺🇸 United States | |
| 8 | Redwood National Park | 🇺🇸 United States | |
| 9 | Channel Islands National Park | 🇺🇸 United States | |
| 10 | Yellowstone National Park | 🇺🇸 United States | |
| 11 | Olympic National Park | 🇺🇸 United States | |
| 12 | Zion National Park | 🇺🇸 United States | |
| 13 | Rocky Mountain National Park | 🇺🇸 United States | |
| 14 | Joshua Tree National Park | 🇺🇸 United States | |
| 15 | Glacier National Park | 🇺🇸 United States | |
| 16 | Acadia National Park | 🇺🇸 United States | |
| 17 | Yosemite National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Edmonton | 🇨🇦 Canada | |
| 2 | Calgary | 🇨🇦 Canada | |
| 3 | Toronto | 🇨🇦 Canada | |
| 4 | Sacramento | 🇺🇸 United States | |
| 5 | San Diego | 🇺🇸 United States | |
| 6 | Portland | 🇺🇸 United States | |
| 7 | Montreal | 🇨🇦 Canada | |
| 8 | Los Angeles | 🇺🇸 United States | |
| 9 | San Francisco | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Silvery Blue sighting in San Francisco on a given day, based on 21 verified sightings from GBIF citizen-science data. It is the 362nd 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.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Silvery Blue in San Francisco on a given day, so our monthly data shows no clear season.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Silvery Blue sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
9th of 9
Of the 9 cities where we can rate Silvery Blue sightings, San Francisco ranks 9th at under 5%. The best odds are in Edmonton (Canada, about 20%), Calgary (Canada, about 10%) and Toronto (Canada, about 10%).
Same family: Lycaenidae
The closest relatives of the Silvery Blue that you can see in San Francisco (family Lycaenidae, Gossamer-winged Butterflies) are Gray Hairstreak (about 10%), Acmon Blue (about 10%) and Western Pygmy-Blue (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Silvery Blue is recorded against all the insects logged in San Francisco (21 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.
