It may sound like a character from a superhero movie, but the viperine is a species of water snake found in the south-western regions of Europe.
Grouped together in the Natricidae family, it makes up one of two water snakes found in Portugal, the other being the Iberian grass snake (Natrix astreptophora).
The term water snake does not mean it lives underwater; it just refers to them being closely associated with water and spending a lot of time in and around a water source.
The name of viperine (Natrix maura) may sound alarming, but, fear not, this snake is harmless, non-venomous and usually very docile. Growing to around 85cm, occasionally longer, these medium-sized snakes can easily be spotted at any inland water source (sometimes even salty coastal lagoons) and often do not flee when humans approach quietly.
Colouring can vary between brown, grey and olive-green with black dots along its body, which can fade with age. These dots often merge into a zigzag pattern like that of a viper. Their underside is usually a yellow or reddish colour with distinct dark rectangles.
When threatened, they will flatten their heads and change their jaw positioning, giving them the typical triangular head shape of a viper, which is why it is named a viperine.
Although documented as active between March and November, here in the south of Portugal, depending on weather conditions, they can be spotted out of hibernation outside of these months.
We are inside their mating season, which occurs during April and May, and if you are lucky – I am yet to see this – you may spot communal mating common in the Natrix species, where multiple males will mate with one single female.
The female will lay her clutch of eggs – usually around seven but can be more than three times this figure – in damp soil or an abandoned hole. It takes four to six weeks for the young to hatch and the babies look extremely cute with their over-sized heads.
Outside of their hibernation period, they are usually considered as diurnal (active during the daytime), however, they can be nocturnal and, in the hottest regions of Portugal, they can switch to nocturnal during the hottest months of the year.
As you would imagine, spending most of their time in and around water, their food source comes from aquatic life. Fish and amphibians are on the menu, and they use their excellent vision, scent and touch to capture their prey.
They can often be found with their tail clinging to a rock or tree, waiting in fast-moving water to ambush any fish that may pass by.
I live on the northern stretch of the Odelouca River and there is a bridge/ford (depending on the river height) that has rocks and plastic tubing which is covered with concrete for vehicle access. I often witness viperines clinging to these rocks next to the fast-moving water, waiting for aquatic life to be washed down river.
I mentioned earlier that these gentle snakes are docile. If you approach slowly, they often do not flee and although they can coil up and take the looks of a viper, they are totally harmless. If really threatened, they can even strike like a viper, but this is all pretence and will not or cannot bite. Therefore, I call it “The Wet Pretender”.
I am often asked to identify snakes from photographs, and I am always happy to do so, however, I have also recently published a new guide to the snakes found in Portugal with links to further information and photographs. This new guide can be found at https://snakes.craigrogers.photography
It is a great way to identify any snakes you have found and to relax any concerns you may have about snakes in Portugal. There is nothing to fear and even the most dangerous one we have in the Algarve region, the Lataste’s viper, carries venom less potent than that of the northern European Adder.
By Craig Rogers
Craig Rogers is a wildlife and nature photographer from Wales now living in the Algarve, offering photography workshops. For more information, photographs and his blog visit