Vipera seoanei
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~80% in a week >90%
Common names: Baskian viper, Iberian cross adder, Portuguese viper, Seoane's viper. Vipera seoanei is a venomous viper species native to extreme southwestern France and the northern regions of Spain and Portugal. Two subspecies are recognized as being valid, including the nominate race described here.
The specific name, seoanei, is in honor of Spanish naturalist Víctor López Seoane y Pardo-Montenegro. Adults of Vipera seoanei may grow to a total length (tail included) of 75 cm (30 in), but usually less. This is a highly polymorphic species for which four main color-pattern types have been described:
A: well-developed, brown zigzig pattern down the back, very much like V. berus, set against a beige or light-gray ground color. B: roughly twin-striped pattern, with the ground color expressed as two narrow, straight, dorsolateral longitudinal lines along the body. Resembles V. kaznakovi to some degree.
C: uniform brownish morph with no pattern. Vipera seoanei is found in extreme southwestern France and the northern regions of Spain and Portugal. The type locality is given... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Picos de Europa National Park | 🇪🇸 Spain | |
| 2 | Pyrénées National Park | 🇫🇷 France |
No species of the same family or order lives in Picos de Europa National Park, so these are its closest relatives here: other reptiles.
Likely
About 40% of wildlife watchers report a Seoane's Viper sighting in Picos de Europa National Park on a given day, based on 95 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 3rd most-seen of the 10 reptiles we can rate there. Over three days the chance rises to about 80%, and over a week to over 90%, if each day is a fresh chance.
April and September
In those months about 50% of wildlife watchers report a Seoane's Viper in Picos de Europa National Park on a given day, against under 5% in June, the lowest month.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Seoane's Viper sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 2 parks where we can rate Seoane's Viper sightings, Picos de Europa National Park has the highest daily chance: about 40%. Next come Pyrénées National Park (France, about 20%).
GBIF citizen-science records
It is estimated from how often the Seoane's Viper is recorded against all the reptiles logged in Picos de Europa National Park (95 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.
