Zamenis scalaris
Silhouette: Beth Reinke · PhyloPic
In 3 days ~30% in a week ~50%
The ladder snake (Zamenis scalaris) is a species of non-venomous snake in the subfamily Colubrinae of the family Colubridae. The species is native to southwestern Europe. The geographic range of the ladder snake includes Portugal, Spain, southern France and just into Italy, also Menorca and the Iles d'Hyères off Provence, but it is absent from northern Iberia including much of the Pyrenees, Galicia (although the species is found on Ons Island, in the Atlantic Islands of Galicia National Park), Cantabria and the Basque Country. The population on Menorca may stem from an introduction by humans.
The ladder snake enjoys scrub bushy cover, including orchards, vineyards, hedges and overgrown dry-stone walls; it is common in the maquis. Habitats with stones and boulders and low shade are preferred. Although known at altitudes over 2,000 metres (6,600 ft), this is a species which prefers altitudes from sea level to 700 metres (2,300 ft).
The ladder snake is a medium-sized snake which reaches a maximum total length (tail included) of around 160 cm (63 in) but which averages 120 cm (47 in) in total length. It has a pointed snout. As an adult... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sierra Nevada National Park | 🇪🇸 Spain | |
| 2 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 3 | Monfragüe National Park | 🇪🇸 Spain | |
| 4 | Doñana National Park | 🇪🇸 Spain | |
| 5 | Cévennes National Park | 🇫🇷 France |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Barcelona Zoo | 🇪🇸 Spain | |
| 2 | Paris Zoological Park | 🇫🇷 France | |
| 3 | Aquarium du palais de la Porte Dorée | 🇫🇷 France | |
| 4 | Aquarama Barcelona | 🇪🇸 Spain | |
| 5 | Reserva Zoológica Oasys MiniHollywood | 🇪🇸 Spain | |
| 6 | Alpenzoo Innsbruck | 🇦🇹 Austria | |
| 7 | South Carolina Aquarium | 🇺🇸 United States | |
| 8 | Public marine aquarium of Trieste | 🇮🇹 Italy | |
| 9 | Reptilandia | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Ladder Snake sighting in Doñana National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 11th most-seen of the 14 reptiles we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
March and May
In those months about 20% of wildlife watchers report a Ladder Snake in Doñana National Park on a given day, against under 5% in April and June–February, the lowest months. Those are among Doñana National Park's wettest months, with about 55 mm of rain a month against almost none in July.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Ladder Snake sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
4th of 5
Of the 5 parks where we can rate Ladder Snake sightings, Doñana National Park ranks 4th at about 10%. The best odds are in Sierra Nevada National Park (Spain, about 20%), Sierra de Guadarrama National Park (Spain, about 10%) and Monfragüe National Park (Spain, about 10%).
GBIF citizen-science records
It is estimated from how often the Ladder Snake is recorded against all the reptiles logged in Doñana National Park (5 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.
