breed. During the terrestrial phase, the newts use hiding places such as logs, bark, planks, stone walls, or small mammal burrows; several individuals may occupy such refuges at the same time. Since the newts generally stay very close to their aquatic breeding sites, the quality of the surrounding terrestrial habitat largely determines whether an otherwise suitable water body will be colonised. Great crested newts may also climb vegetation during their terrestrial phase, although the exact function of this behaviour is not known at present. The juvenile efts often disperse to new breeding sites, while the adults in general move back to the same breeding sites each year. The newts do not migrate very far: they may cover around in one night and rarely disperse much farther than . Over most of their range, they hibernate in winter, using mainly subterranean hiding places, where many individuals will often congregate. Diet and predators Northern crested newts feed mainly on invertebrates. During the land phase, prey include earthworms and other annelids, different insects, woodlice, and snails and slugs. During the breeding season, they prey on various aquatic invertebrates (such as molluscs, microcrustaceans, and insects), and also tadpoles of other amphibians such as the common frog or common toad, and smaller newts. Larvae, depending on their size, eat small invertebrates and tadpoles, and also smaller larvae of their own species. The larvae are themselves eaten by various animals such as carnivorous invertebrates and water birds, and are especially vulnerable to predatory fish. Adults generally avoid predators through their hidden lifestyle but are sometimes eaten by herons and other birds, snakes such as the grass snake, and mammals such as shrews, badgers and hedgehogs. They secrete the poison tetrodotoxin from their skin, albeit much less than for example the North American Pacific newts (Taricha). The bright yellow or orange underside of crested newts is a warning coloration which can be presented in case of perceived danger. In such a posture, the newts typically roll up and secrete a milky substance. Courtship and reproduction Northern crested newts, like their relatives in the genus Triturus, perform a complex courtship display, where the male attracts a female through specific body movements and waves pheromones to her. The males are territorial and use small patches of clear ground as leks, or courtship arenas. When successful, they guide the female over a spermatophore they deposit on the ground, which she