Search results for "Natrix"

Habitat ecology of the smooth snake Coronella austriaca and its reptilian prey in the degraded bog with implications for artificial refuge surveys

2016

AbstractDiet preferences of the smooth snake (Coronella austriaca) being still controversial, we studied the overlap between its habitat and that of its potential reptilian prey species using the artificial refuge (ATR) method. The discriminant function analysis revealed that part of the smooth snake’s habitat niche is unused by one of its prey species – Zootoca vivipara. The smooth snake was recorded more often in places with high density of individuals of another lizard species – Anguis fragilis. Occasional data on snake diets supported the assumption that the latter species is a very important food item for the smooth snake in the study area. Our study estimated the minimum number of tim…

Dati preliminari sulla biometria, il cromatismo e la dieta di una popolazione di Natrix natrix della Sicilia occidentale.

2010

First documented cases of defensive biting behaviour towards humans by the Italian Barred Grass Snake, Natrix helvetica sicula (Cuvier, 1829)

2023

We report the first documented cases of defensive biting behaviour towards humans by the Italian Barred Grass Snake,

Primi dati sull’uso dell’habitat in una popolazione siciliana di Natrix natrix.

2013

First data about the habitat use in a population of Natrix natrix from Sicily. In the present paper the preliminary results of an investigation carried out on a Sicilian population of the grass snake (Natrix natrix) are reported. The leading aim of this study is to compare habitat use among three different classes of individuals (males, females, immatures), using as input the density of observations in four habitat types. Field studies were conducted beside a reservoir (“Lago di Scanzano”), located about 40 km from Palermo (western Sicily). Our results indicate spatial and temporal differences among groups. Young individuals were observed more frequently between April and May along wet mead…

DISTRIBUTION AND CHARACTERIZATION OF MELANISM IN GRASS SNAKES FROM ITALY

2022

In snakes, melanism can improve thermoregulation efficiency, reproductive success and provide additional protection to internal organs from solar radiation. For these reasons, such conditions could be beneficial for animals living in both cold and warm environments. For widely distributed species of grass snake (genus Natrix), several single encounters of melanic individuals are reported in the literature. In the period 2015-2021 a significant number of unpublished observations of melanic Natrix helvetica and N. natrix were collected on the Italian territory and integrated with bibliographic data. The present work illustrates the chromatic variation within melanic individuals and investigat…

Strongyloides natricissp. n. (Strongyloididae), un nouveau nématode parasite deNatrix maura(L. 1758) (Colubridae) en Espagne

1993

Description d’une nouvelle espece de Nematode Strongyloididae, Strongyloides natricis sp. n. trouvee chez Natrix maura (L. 1758) (Colubridae), capturee a Mora de Rubielos, Teruel, Espagne. L’espece presente entre autres caracteres distinctifs une plus grande taille corporelle et des longueurs oesophagienne et caudale proportionnellement inferieures a celles de toutes les autres especes de ce genre.

Antipredatory function of head shape for vipers and their mimics.

2011

Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the subfamily Natricinae, commonly flatten their heads (also known as head triangulation) when disturbed. The adaptive significance of this potential behavioural mimicry has never been investigated. We experimentally tested if the triangular head shape typical of vipers offers protection against predation.…

Antipredatory Function of Head Shape for Vipers and Their Mimics

2011

Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the subfamily Natricinae, commonly flatten their heads (also known as head triangulation) when disturbed. The adaptive significance of this potential behavioural mimicry has never been investigated. We experimentally tested if the triangular head shape typical of vipers offers protection against predation.…