Ladder Snake

The ladder snake is one of the most familiar large snakes of the Iberian Peninsula, occupying open, sun-baked habitats across Spain and Portugal. It is a powerful constrictor within the ratsnake group (genus Zamenis) and is harmless to humans, though it may bite defensively if handled.

Its common name comes from the juvenile pattern of paired dark bars connected by cross-bars resembling rungs of a ladder, a pattern that largely disappears with age.

• Juveniles show a distinct ladder-like pattern of two dark stripes joined by short crossbars
• Adults are typically pale yellowish-brown to olive with two dark, mostly unbroken longitudinal stripes running the length of the body
• Head is narrow and only slightly distinct from the neck
• Scales are smooth to weakly keeled, giving a somewhat glossy appearance
• Robust, muscular build typical of large colubrids
• Round pupils

Found in dry, open, and often disturbed habitats including scrubland, stone walls, vineyards, olive groves, hedgerows, and rocky hillsides. It ranges from sea level to over 1,500 m elevation across Spain, Portugal, and a small area of southern France, favoring sunny microhabitats with cover such as rock piles and debris.

Diurnal and active in warm weather, often seen basking on stone walls or crossing roads. When threatened it may flatten its body, hiss loudly, and strike, though it is not dangerous. Diet consists mainly of small mammals, birds, and their eggs, taken by active foraging and constriction. Reproduction is oviparous, with females laying 5-12 eggs in summer.