Italian crested newt
When newts are inactive or in oxygen-rich environments, respiration can be done through their skin which accounts for 74% of the cutaneous respiration. However, oxygen-poor environments, such as stagnant ponds, pose a threat to the survival of larval newts. This is because oxygen molecules do not readily dissolve in water, and as "T. carnifex" is an immobile animal, extracting oxygen from water is difficult. Newts consequently have external gills at birth that persist until metamorphosis, which assists survival in low-oxygen conditions.
Newt fencing
The great crested newt’s natural habitat requirements are standing fresh water for breeding purposes, but the majority of its time is spent on dry land. They favour semi-natural habitats such as rough grassland, hedgerows and scrub woodland. An individual newt tends to have a range centred upon its breeding pool. The breeding stage of the life cycle takes place in spring, from February through to April. After this it spends much of its time on land, usually within from the breeding pond, but sometimes ranging up to . Unfortunately this life cycle and the use of both terrestrial and aquatic habitas may put the newts into conflict with humans. Brownfield sites often contain very good terrestrial habitat for great crested newts, and land within from newt breeding ponds includes a significant proportion of the UK.