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Poisonous snakes

Not all snakes are poisonous, not are all snake poisons lethal to men. Even if they are, efficacy of the poison depends whether the snake has previously caught a prey and emptied poison sacks, the size of the snake, age and size of the man, location of the bite, etc. Snakes use the poison above all to overcome the prey, but it has digestive function, as well. Since snakes swallow their prey in one piece, the poison serves to start the digestion process in the mouth.
For that reason the poison is, in fact, a water solution of various enzymes, toxins and other proteins.


Only three species of for men poisonous snakes live in Croatia and Bosnia & Herzegovina that:

  • Nose-horned Viper, local name Poskok (Vipera ammodytes)
  • Common Adder, local name Riđovka (Vipera berus bosniensis)
  • Karst Meadow Viper, local name Planinski žutokrug (Vipera ursini macrops)

Bite signs at the place of the bite one can see two small wounds made by snake teeth. Sometimes only one can be seen. The very bite does not mean the snake has injected the poison. In as much as 22% of proved bites, signs of poisoning did not exist.
Signs of poisoning (not all have to be distinct): Dizziness, Nausea and vomiting, Pain and swelling at the place of the bite, Swelling of lymph nodes at the groin after a bite in the leg, or armpit after a bite in the arm, Shock is the most dangerous effect of the bite.


  • Bitten person has to lay still.
  • Immobilize leg or arm where the bite wound is. In that way you can slow down spreading of the poison in the organism.
  • Transport the person to the nearest hospital as soon as possible.

    DO NOT
  • tie off the bitten limb
  • cut the wound
  • suck out the poison
  • put ice on the bite wound.

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Common Adder - Riđovka (Vipera berus bosniensis)

Common Adder - Riđovka (Vipera berus bosniensis)

Description: Adults are usually up to 65 cm, rarely 80 cm (even 90 cm), females are larger than males. Tail is 1/5-1/6 of total body length. Body is rather stout, has a flat (not upturned) snout (but van be sometimes mildly upturned). Most Adders have a clearly marked zig-zag stripe on back. This is usually without a very distinct paler central band (as in some other similar vipers). In rare cases the zig-zag is straight-edged, broken up, faint or even absent. Colouring varies: males are very contrasting (especially in spring), often being whitish or pale grey with intense black markings. Females are frequently brownish or reddish with dark brown markings. Other colour combinations exist and entirely black (melanistic) animals may be common (in polar areas up to 50%). Youn are often reddish,. Belly is grey, grey-brown or black, sometimes with white spots. Tail tip is yellow, orange or even red beneath.

Habitat: Occurs on a wide variety of habitats, particularly in north of range. Here it is found on moors, heaths and dunes, and in bogs, open woods, field-edges, hedgerows, marshy meadows, and even salt marshes. In the south is more restricted and usually found in mountain areas, lowlands...

Venom: Quite potent, though bites are not that dangerous as those of teh Asp Viper (Vipera aspis) and Nose-horned Viper (Vipera ammodytes). Fangs of adult Adders are 4 mm long. In humans bites cause sweling, pain, the surrounding tissue is destroyed, in later stages can cause nausea and vomiting. For healthy adults a bite is not life threatening, but it is still recommended to seek medical help. Human fatalities are very rare. The bosnian subspecies (Vipera b. bosniensis) has a stronger venom that the normal subspecies (V. b. berus).


Nose-horned Viper - Poskok (Vipera ammodytes)

Description: Adults are usually between 60-80 cm, males larger than females and can reach 100 cm. The only eastern European snake with a distinct nose-horn. Body relatively stout. Males are greyish, females are brownish, greyish-brown, reddish-brown. Rarely yellow (1), pinkish or greenish. Melanism (entirely black individuals) is very rare. A dark (black, brown-black) line that forms a zig-zag on back (doesn't have to be continuously connected). Only in rare cases is the zig-zag pale or more as a line. Belly is pink, greyish, spotted (darkly). Underside of tail is red, orange, pink, green, yellowish... Back scales are keeled.

Habitat: Most favourite are dry sunny habitats with some vegetation and rocks (rock-piles, dry-stone walls, meadows with dense low bushes...).

Venom: Europe's most venomous snake, in the past caused regular human deaths (today that possibility is rare, normally about a week's stay in hospital, severe symptoms of poisoning). Fangs can be up to 1 cm long. Dramatic swelling of the bite site, hurts a lot. By venom strength (in Croatia), populations around Slunj have the most potent venom. Second are those on Velebit, third are those around Zagreb and furth are those around Krapina.


Karst Meadow Viper - Planinski žutokrug (Vipera ursini macrops)


Description: Adults are usually less than 50 cm, rarely over 60, females are larger than males. The smallest European viper: a small, thick bodied snake, with a narrow head, often has a rough appearance. Only likely to be confused with the Asp Viper (Vipera aspis) or Adder. Differs from Asp Viper in lacking an obvious upturned snout and always has several large scales on top of head and has a low number of dorsal scales. Differs from Adder in smaller adult size, has a narrower head with a more tapering snout and in several features in head scaling. Dorsals are wavy in cross-section, have a distinct keel and are often rather short so dark skin between them is visible. These features give the snake a rough texture. Pattern is often not very variable: usually greyish, pale brown or yellowish with a dark zig-zag dorsal stripe that is usually edged with black and can be occasionally broken into spots. Flanks often rather dark, belly can be blackish, whiteish or dark grey, even pinkish, with or without spots. Underside of tail is sometimes dark or with yellowmarkings.

Habitat: V. u. macrops is a mountain form, occuring above 1000 m above sea level. Lives on well drained hill sides with some vegetation, but more often encountered on high, often dry, meadows.

Venom: Weaker than that of the other vipers. That in combination with it's placid disposition makes Orsini's Viper the least dangerous European viper, but with possible misidentification with more dangerous Adders (V. berus berus and V. b bosniensis) they should still be treated with respect. In humans, a bite causes local pain and swelling. In more sensitive persons can cause nausea and throwing up, but recovery is usually swift. No deaths have been recorded.