COLLAR SNAKE natrix natrix, from the Latin matrix, 'swimmer'. Non-venomous snake of the family Colubridae, native to Eurasia and northwest Africa. It is found throughout Europe, except in the northern part. Adult males can reach one meter, but there are females that reach 2 meters. Some specimens have a characteristic yellowish or orange collar bordered behind a black spot. It is very sharp in the young, blurs as they grow and seems to become dimmer in adult individuals. They are seen on the banks of rivers, wells and small lakes, in dry and stony places, in coastal dunes and forests, as well as in fountains and cisterns, temporarily settling in orchards and gardens. They prefer shrubby, arid or wooded areas that are at a certain distance from the water. It is perched until the age of 2. 500 m altitude. During the winter the collared snake hibernates; shortly after leaving this state, in spring during April or May, it mates. Copulation can also take place during the fall, though rarely. From June to July it lays eggs in groups of 8 to ( most often, from 10 to 15. These hatch after about 4 to 10 weeks, around September. To do this, they require a temperature of 21 ° C, so the female does the laying in hot and humid places, often on rotting vegetation or piles of manure. The young measure 18 cm when leaving the egg and are immediately independent. The collared snake feeds on amphibians (especially frogs, toads, salamanders and newts), although it can also hunt small mammals, fish and birds. It is quite aquatic; it swims very well on the surface, with the head stiff out of the water, but it can remain submerged for a long time. Although it is aggressive, for the human being it is completely harmless. If she feels threatened she will rise with a swollen neck, whistling and hitting with her muzzle faking the attack, but she will not normally bite. It can also be dead, remaining motionless and expelling through the sewer a nauseating smell to give more veracity to its performance. It is a diurnal species, but if during the day it is very hot, it will prefer to go out at night.
