{"id":3149,"date":"2020-01-18T19:35:26","date_gmt":"2020-01-18T19:35:26","guid":{"rendered":"http:\/\/www.moroccoherps.com\/?page_id=3149"},"modified":"2025-02-27T22:08:52","modified_gmt":"2025-02-27T22:08:52","slug":"natrix_astreptophora","status":"publish","type":"page","link":"https:\/\/www.moroccoherps.com\/en\/ficha\/natrix_astreptophora\/","title":{"rendered":"Species page of Natrix astreptophora"},"content":{"rendered":"

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Iberian Grass Snake
\nNatrix astreptophora\u00a0<\/em>(Lopez-Seoane, 1984)<\/h1>\n<\/div>\n
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By\u00a0Daniel Escoriza<\/b><\/p>\n<\/div>\n<\/div>\n

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Updated:\u00a07\/12\/2014<\/b><\/p>\n<\/div>\n

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Taxonomy:\u00a0Serpentes\u00a0|\u00a0Natricidae\u00a0|\u00a0Natrix\u00a0|\u00a0Natrix astreptophora<\/p>\n<\/div>\n<\/div>\n

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\"Natrix
Adult specimen from Jebala, with a marked nuchal ring. Photo: \u00a9 Daniel Escoriza.<\/figcaption><\/figure>\n<\/div>\n
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\"Range<\/p>\n

\"\"\u00a0\u00a0Natrix astreptophora<\/span><\/p>\n

Distribution map of
\nNatrix astreptophora<\/span>
\nin Morocco.<\/p>\n<\/div>\n

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Gallery: 1 photo.\u00a0[ENTER]<\/a><\/p>\n

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Phylogenetic frame<\/h2>\n

The genus\u00a0Natrix<\/span>\u00a0forms a monophyletic genus which is distributed throughout most of the Western Palaearctic region, from the subarctic region in Scandinavia to the margin of subtropical deserts in northern Africa. In this ecozone appear three species (considering\u00a0N. megalocephala<\/span>\u00a0as invalid species; Jandzik 2005), and the three occur also in North Africa:\u00a0N. maura<\/span>\u00a0and\u00a0N. natrix<\/span>\u00a0in the Maghreb and\u00a0N. tessellata<\/span>\u00a0in isolation in the Nile Delta (Sindaco\u00a0et al<\/em>., 2013).<\/p>\n

N. natrix<\/span>\u00a0is the most widespread species of the genus, and shows more phenotypic diversity in the Mediterranean basin, being the southwestern clade (astreptophora<\/span>) located at a more basal phylogenetic position (Guicking\u00a0et al<\/em>., 2006; Fritz\u00a0et al.<\/em>, 2012). According to Mertens (1947) in North Africa would occur the Iberian Peninsula subspecies\u00a0N. natrix astreptophora<\/span>, characterised by a uniform gray color and the absence of nuchal-occipital ring in adults. However Sochurek (1979) proposed that the North African populations should be assigned to a new subspecies,\u00a0N. natrix algirus<\/span>, because the North African specimens do not show a gradual loss of nuchal-occipital ring during ontogenetic development.<\/p>\n

Description<\/h2>\n

A beautiful snake of moderate size, which can reach 120\u00a0cm in length, although there may be larger specimens (Bruno & Maugeri 1990). Based on specimens of the Rif and the Atlantic coast of Morocco: head not clearly distinct from the body, with rounded pupils and red iris. Cephalic scales large and distinct. Seven supralabials, third and fourth in contact with the eye, white and trimmed in black. The North African specimens may show a nuchal ring more or less apparent in adulthood. Robust body with keeled dorsal scales. Dorsal coloration olive gray background with an alternating pattern of oval spots, or without any pattern. Belly whitish with dark spots in alternating pattern. Young specimens with a marked nuchal-occipital ring.<\/p>\n

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\"Natrix
Adult specimen from Rif, withouth any body and nuchal pattern, similar to the astreptophora phenotype present in the Iberian Peninsula. Photo: \u00a9 Mario Schweiger.<\/figcaption><\/figure>\n<\/div>\n
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\"Natrix
Juvenile from Jebala, showing some of the typical features of N. astreptophora that easily separated this species from N. maura: posterior cephalic scales dark, contrasted nuchal collar and a dorsal pattern relatively uniform, although alternating scattered black spots. Photo: \u00a9 Daniel Escoriza.<\/figcaption><\/figure>\n<\/div>\n

Ecology and habits<\/h2>\n

The specific ecology of the species in northern Africa is poorly known (Schleich\u00a0et al<\/em>., 1996; Bons and Geniez, 1996). Overall it is a species relatively linked to wetlands and their surroundings, but can be found far away from the water. It feeds on larvae of amphibians, fish and adult amphibians, which can capture on land, particularly toads, sometimes even large individuals.<\/p>\n

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\"Natrix
Natrix astreptophora predating on Amietophrynus mauritanicus. Rif. Photo: \u00a9 Ahmed Idrissi.<\/figcaption><\/figure>\n<\/div>\n

In Morocco, the activity may continue for much of the year and I have seen active young specimens to late November in elevated areas of the western Rif. In most of these places it appears sympatrically with\u00a0N. maura<\/span>, with which might appear trophic competition (Luiselli, 2006).<\/p>\n

Distribution, habitat and abundance<\/h2>\n

N. natrix<\/span>\u00a0is distributed by the Mediterranean regions of North Africa, usually limited to sub-humid and humid ombroclimates (rainfall above 500 mm\/year) in mountain areas in the Rif and Middle Atlas (Fahd and Pleguezuelos, 1992), where it reaches up to 2,000 m (Bons and Geniez, 1996). However locally it can also occur in lowlands, as in the Moroccan Atlantic plain (Mateo\u00a0et al<\/em>.. 2003; Escoriza\u00a0et al<\/em>., 2012) and in northern Tunisia (around Lake Ichkeul), favoring the moist microclimate maintained by riparian forests. In Morocco the distribution of\u00a0N. natrix<\/span>\u00a0can be associated with a humid Mediterranean chorotype, which typically occupy some “relict” species with Eurasian affinities such as\u00a0E. orbicularis<\/span>\u00a0(Mediani\u00a0et al<\/em>., 2009),\u00a0C. girondica<\/span>\u00a0(Real\u00a0et al<\/em>., 1997) and amphibians as\u00a0P. varaldii<\/span>\u00a0(Hamoumi and Himmi, 2010; Escoriza and Ben Hassine, 2013) and\u00a0A. maurus<\/span>\u00a0(Marquez\u00a0et al<\/em>., 2011).<\/p>\n

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\"H\u00e1bitat
Meso-thermal cork oak forest, typical habitat of N. astreptophora in Morocco (Jebala mountains). Foto: \u00a9 Daniel Escoriza.<\/figcaption><\/figure>\n<\/div>\n

The habitat occupied by this species in Morocco is highly variable, as occurs in the Iberian Peninsula (Bra\u00f1a, 1998). This snake can occupy open habitats, such deltaic marshes and extensive agricultural lands, but also areas of dense vegetation, such as meso-thermal forests of holm and cork oaks, usually associated with the close presence of permanent and seasonal ponds, streams and springs.<\/p>\n

N. natrix<\/span>\u00a0is scarce in Morocco and elsewhere in North Africa (Doumergue, 1901; Schleich\u00a0et al<\/em>., 1996; Escoriza\u00a0et al<\/em>., 2012). Several factors may adversely affect populations of this species, such as the destruction of riparian forests and alteration of aquatic habitats, which directly affect this snake and the amphibian populations on which it feeds. However some of these populations are in protected areas such as Sidi Boughaba and Jbel Bouhachem reserves, which can promote the survival of this interesting species, at least in these sites.<\/p>\n

References<\/h3>\n