Ischnura cervula
In 3 days ~10% in a week ~30%
Ischnura cervula, the Pacific forktail, is a species of narrow-winged damselfly in the family Coenagrionidae. It is found in western North America. The species is notable for its female color polymorphism, occurring in an andromorphic or heteromorph form. Ischnura cervula occupy freshwater habitats, including springs, wetlands, and slow-moving waters with surrounding vegetation. The species also acts as an intermediate host for the lung fluke Haematoloechus longiplexus, introduced via American bullfrogs. Although listed as Least Concern by the IUCN, habitat loss, poor water quality, and climate change can negatively impact Ischnura cervula populations.
The Pacific Forktail is a western North American species that is present from southern British Columbia to Arizona and as far east as Alberta. Ischnura cervula populations have been observed at spring habitats in Banff National Park, Canada, which has many wetlands, slow-moving streams with surrounding vegetation. A comprehensive California Odonata database also records the species' presence over a century of records, highlighting how the distribution has changed over time and recognizes any emergent... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Redwood National Park | 🇺🇸 United States | |
| 2 | Channel Islands National Park | 🇺🇸 United States | |
| 3 | Great Bear Rainforest | 🇨🇦 Canada | |
| 4 | Yellowstone National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Portland | 🇺🇸 United States | |
| 2 | Seattle | 🇺🇸 United States | |
| 3 | Vancouver | 🇨🇦 Canada | |
| 4 | Sacramento | 🇺🇸 United States | |
| 5 | San Francisco | 🇺🇸 United States | |
| 6 | Los Angeles | 🇺🇸 United States | |
| 7 | San Diego | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Pacific Forktail sighting in Yellowstone National Park on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 127th most-seen of the 160 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
In that month about 10% of wildlife watchers report a Pacific Forktail in Yellowstone National Park on a given day, against under 5% in September to July, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Pacific Forktail sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 4
Of the 4 parks where we can rate Pacific Forktail sightings, Yellowstone National Park ranks 4th at under 5%. The best odds are in Redwood National Park (United States, about 10%), Channel Islands National Park (United States, about 10%) and Great Bear Rainforest (Canada, about 10%).
Same family: Coenagrionidae
The closest relatives of the Pacific Forktail that you can see in Yellowstone National Park (family Coenagrionidae, Narrow-winged Damselflies) are Vivid Dancer (about 10%), Western Red Damsel (about 10%) and Paiute Dancer (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Pacific Forktail is recorded against all the insects logged in Yellowstone National Park (11 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.
