and southern ranges. In the absence of forests, other cover-rich habitats, as for example hedgerows, scrub, swampy meadows, or quarries, can be inhabited. Preferred aquatic breeding sites are stagnant, mid- to large-sized, unshaded water bodies with abundant underwater vegetation but without fish (which prey on larvae). Typical examples are larger ponds, which need not be of natural origin; indeed, most ponds inhabited in the United Kingdom are human-made. Examples of other suitable secondary habitats are ditches, channels, gravel pit lakes, or garden ponds. Other newts that can sometimes be found in the same breeding sites are the smooth newt (Lissotriton vulgaris), the palmate newt (L. helveticus), the Carpathian newt (L. montadoni), the alpine newt (Ichthyosaura alpestris) and the marbled newt (Triturus marmoratus). The northern crested newt is generally a lowland species but has been found up to in the Alps. Population structure, speciation, and phylogeny Hybridization In certain areas of France, the northern crested newt and the marbled newt overlap, and hybrids are present. As the northern crested newt's population grows, and marbled newt population struggles, these hybrids have been shown to possess good qualities of both. They have more fecundity than the two newts however have a hard time keeping their eggs alive. Life cycle and behaviour Like other newts, T. cristatus develops in the water as a larva and returns to the water each year for breeding. Adults spend around seven months of the year on land. After larval development in the first year, juveniles pass another year or two before reaching maturity; in the north and at higher elevations, this can take longer. The larval and juvenile stages are the riskiest for the newts, while survival is higher in adults. Once the risky stages passed, adult newts usually have a lifespan of seven to nine years, although individuals have reached 17 years in the wild. Adult newts begin moving to their breeding sites in spring when temperatures stay above , usually in March. In the aquatic phase, crested newts are mostly nocturnal and, compared to smaller newt species, usually prefer the deeper parts of a water body, where they hide under vegetation. As with other newts, they have to occasionally move to the surface to breathe air. The aquatic phase serves not only for reproduction, but also offers more abundant prey, and immature crested newts frequently return to the water in spring even if they do not