| Ladder snake | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Colubridae |
| Genus: | Zamenis |
| Species: | Z. scalaris |
| Binomial name | |
| Zamenis scalaris (Schinz, 1822) | |
 | |
| Range map | |
| Synonyms [2] | |
| |
The ladder snake (Zamenis scalaris) is a species of non-venomous snake in the family Colubridae. The species is endemic 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 [3] ), Cantabria and the Basque Country. [4] The population on Menorca may stem from an introduction by humans. [1]
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). [4]
The ladder snake is a medium-sized snake which reaches a maximum total length (including tail) of around 160 cm (63 in) but which averages 120 cm (47 in). It has a pointed snout. As an adult the ladder snake is less variable than many related snake species, the basic colour goes from yellowish to dark brown, with two darker stripes running down the length of the body from neck to tail. It normally also has a dark stripe running from the rear of the eye to the angle of the jaw and sometime subtle, darker markings on the sides. The ventral side is pale, varying from a silvery-grey to whitish, with the occasional dark spot. The eye is dark. The juvenile snakes have lighter and brighter colouration, varying from yellow to light brown, with the characteristic “ladder” pattern picked out in black along the upperside. The pale underside has black markings which sometimes coalesce to cover the whole of the underside. As the snake ages these colours and patterns fade until the simpler adult pattern is left. [4]
Like other “rat snakes”, the majority of the ladder snake’s prey is mammals such as mice, rabbits and shrews, making up 75% of prey items with a further quarter being spiders, insects (especially grasshoppers) and a few birds. To prey on birds the ladder snake will climb to search for active nests in trees or on man-made structures. Lizards are also eaten. Juvenile ladder snakes prefer small lizards, baby rodents, spiders, and grasshoppers. [4]
The ladder snake is normally active by day, but during the hottest summer months it may be nocturnal, while in the spring months it may be more crepuscular. Its behaviour is said to be more like that of whipsnakes rather than that of rat snakes. It is more aggressive and defensive than most of the species formerly classified alongside it in the genus Elaphe . Defensive signals include hissing and lunging forward with the mouth open. Any attempt to pick up a ladder snake may be greeted by sharp bites and also the emptying of the cloacal glands, releasing an offensive odour. [4]
It is a more mobile snake than many of its relatives and movements of up to 100 m per day have been recorded, while the average home territory of an individual is 4,500 m2. Adults may enter barns or similar buildings in search of rodent prey, but they do not normally use such places for shelter and prefer rodent burrows, piles of stones or hollow trees. [4]
In Iberia ladder snake courtship occurs during May and June, however some females do not breed every year. Copulation lasts around an hour, and a clutch with an average size of 15 eggs (varies between 4 and 24 eggs) is laid 3–6 weeks after mating. Incubation takes between 5 and 12 weeks. The young measure 20 cm (7.9 in) long as hatchlings. Unusually for snakes, their mother may remain with the newly hatched juveniles for a few days. Males and females reach sexual maturity at approximately 5 years of age, when they reach a length of 50 cm (20 in) and 65 cm (26 in), respectively. [4]
The IUCN has rated this species as Least Concern. This is a generally abundant species which is tolerant of a wide range of habitats and has a large geographic range. [1]
Pantherophis obsoletus, also known commonly as the western rat snake, black rat snake, pilot black snake, or simply black snake, is a nonvenomous species of snake in the family Colubridae. The species is native to central North America. There are no subspecies that are recognized as being valid. Its color variations include the Texas rat snake. Along with other snakes of the eastern United States, like the eastern indigo snake and the eastern racer, it is called “black snake”.
The Persian ratsnake is a species of medium-sized nonvenomous snake in the family Colubridae. The species is endemic to Western Asia.
The Aesculapian snake is a species of nonvenomous snake native to Europe, a member of the Colubrinae subfamily of the family Colubridae. Growing up to 2 metres (6.6 ft) in length, it is among the largest European snakes, similar in size to the four-lined snake and the Montpellier snake. The Aesculapian snake has been of cultural and historical significance for its role in ancient Greek, Roman and Illyrian mythology and derived symbolism.
Hardwicke's rat snake, also known commonly as the glossy-bellied racer, Gray's rat snake, and the spotted bellied snake, is a species of snake in the family Colubridae. The species is native to Asia. There are three recognized subspecies.
The trinket snake, also known commonly as the common trinket snake, is a species of nonvenomous constricting snake in the family Colubridae. The species is native to southern Central Asia.
Elaphe hodgsoni, also known commonly as Hodgson's rat snake and the Himalayan trinket snake, is a species of snake in the family Colubridae. The species is native to parts of Asia around the Himalayas.
Ptyas mucosa, commonly known as the Oriental rat snake, dhaman or Indian rat snake, is a common non-venomous species of colubrid snake found in parts of South and Southeast Asia. Dhamans are large snakes. Typical mature total length is around 1.5 to 1.95 m though some exceed 2 m. The record length for this species was 3.7 m, second only to their cousin Ptyas carinata among living colubrid snakes. Despite their large size, oriental ratsnakes are usually quite slender with even a specimen of 2 m commonly measuring 4 to 6 cm only around in diameter. Furthermore, the average weight of ratsnakes caught in Java was around 877 to 940 g, though larger males of over 2.3 m may easily weigh over 2.5 kg (5.5 lb). Their color varies from pale browns in dry regions to nearly black in moist forest areas. Rat snakes are diurnal, semi-arboreal, non-venomous, and fast-moving. Rat snakes eat a variety of prey and are frequently found in urban areas where rodents thrive.
Masticophis flagellum is a species of nonvenomous colubrid snake, commonly referred to as the coachwhip or the whip snake, which is endemic to the United States and Mexico. Six subspecies are recognized, including the nominotypical subspecies.
The eastern racer, or North American racer, is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America and Central America. Eleven subspecies, including the nominotypical subspecies, are recognized, which as a group are commonly referred to as the eastern racers. The species is monotypic in the genus Coluber.
Coluber constrictor oaxaca, commonly known as the Mexican racer, is a nonvenomous colubrid snake, a subspecies of the eastern racer.
Pantherophis bairdi is a species of harmless snake in the family Colubridae. The species is native to the southwestern United States and adjacent northeastern Mexico. No subspecies are recognized as being valid.
Euprepiophis conspicillata, commonly known as the Japanese forest rat snake, is a species of nonvenomous colubrid snake endemic to Japan. Its Japanese common name, jimuguri, roughly translates to "the burrower". It is closely related to Euprepiophis mandarinus, the Mandarin rat snake.
Elaphe quadrivirgata, commonly known as the Japanese four-lined ratsnake or the Japanese striped snake, is a species of non-venomous colubrid snake native to Japan.
The horseshoe whip snake is a species of snake in the family Colubridae. The species is native to southwestern Europe and northern Africa.
The European ratsnake or leopard snake, is a species of nonvenomous colubrid snake endemic to Europe, Asia Minor, and the Caucasus.
The striped whipsnake is a species of nonvenomous snake in the family Colubridae. It is closely related to the California whipsnake. The striped whipsnake is native to the western United States and adjacent northern Mexico.
Elaphe quatuorlineata is a member of the family Colubridae. The four-lined snake is a non-venomous species and one of the largest of the European snakes.
Pantherophis alleghaniensis, commonly called the eastern rat snake, is a species of non venomous snake in the family Colubridae. The species is endemic to North America.
The Transcaucasian ratsnake, also commonly known as the Gavand snake, is a species of nonvenomous ratsnake in the family Colubridae. The species is native to Western Asia and the Middle East. There are three recognized subspecies.
Elaphe davidi, also known commonly as Pere David's rat snake, is a species of snake in the family Colubridae. The species is endemic to East Asia.
