Ascaphus truei
Silhouette: Sarah Werning · PhyloPic
In 3 days ~30% in a week ~60%
The tailed frogs are two species of frogs in the genus Ascaphus, the only taxon in the family Ascaphidae. The "tail" in the name is actually an extension of the male cloaca. The tail is one of two distinctive anatomical features adapting the species to life in fast-flowing streams. These are the only North American frog species that reproduce by internal fertilization. They are among the most primitive known families of frogs.
Its scientific name means 'without a spade', from the privative prefix a- and the Ancient Greek skaphís (σκαφίς, 'spade, shovel'), referring to the metatarsal spade, which these frogs do not have. However, in that year, Nielson, Lohman, and Sullivan published evidence that promoted the Rocky Mountain tailed frog (Ascaphus montanus) from a subspecies to its own species. Since then, the former species has been formally called the coastal tailed frog.
The genus Ascaphus, through mtDNA comparisons, has been grouped into a clade with the genus Leiopelma creating a sister taxon to all modern anurans. Wikipedia →
Recording0:07
United States · 2024
© Mara · iNaturalist · CC BY 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Redwood National Park | 🇺🇸 United States | |
| 2 | Olympic National Park | 🇺🇸 United States | |
| 3 | Great Bear Rainforest | 🇨🇦 Canada |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Vancouver | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a Coastal Tailed Frog sighting in Olympic National Park on a given day, based on 52 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 7th most-seen of the 13 amphibians we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
August and September
In those months about 20% of wildlife watchers report a Coastal Tailed Frog in Olympic National Park on a given day, against under 5% in October to February, the lowest months. Those are among Olympic National Park's driest months, with about 85 mm of rain a month against 370 mm in November.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Coastal Tailed Frog sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 3
Of the 3 parks where we can rate Coastal Tailed Frog sightings, Olympic National Park ranks 2nd at about 10%. The best odds are in Redwood National Park (United States, about 30%).
Same order: Anura
The closest relatives of the Coastal Tailed Frog that you can see in Olympic National Park (order Anura, Frogs and Toads) are Western Toad (about 30%), Cascades Frog (about 20%) and Northern Red-legged Frog (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Coastal Tailed Frog is recorded against all the amphibians logged in Olympic National Park (52 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.
