The northern crested newt, more colloquially known as the great crested newt or warty newt, is a species of amphibian found in Great Britain. Compared to other newt species, the northern crested newt is rather large.
The northern crested newt is a relatively large newt species. Male animals of this species typically grow to be 13.5 cm (5.3 inches) long, while females can reach 16 cm (6.3 in).
According to the International Union for Conservation of Nature, the northern crested newt is classified as Least Concern. However, despite this classification, populations of the northern crested newt have been declining due to habitat destruction from urban sprawl and other human activity.
The northern crested newt lives on land for the majority of the year, typically in forested zones located in low-lying areas. In spring, it migrates to its aquatic breeding sites which are often larger ponds without fish.
Their best sites to breed are usually stagnant, have an ample amount of vegetation, and are neither too big nor too small. Other preferred habitats include channels, ditches, garden ponds, or gravel pit lakes.
The northern crested newt has a dark brown back and sides, with a yellow to an orange belly that has dark blotches. Jagged crests appear on the back and tail of males during the breeding season. Their body shape corresponds with their skeletal build: it has 15 rib-bearing vertebrae!
Furthermore, the cloaca of a male will enlarge during the breeding season and will have blue-white stripes lateral to the tail. There is no such development in females, though.
The primary food source for northern crested newts is invertebrates. These newts’ diet is not restricted to just one phase of their lives; they consume both earthworms and other annelids, as well as various insects during the land phase. However, their breeding season sees a change in appetite where they primarily hunt for aquatic invertebrates.
The males establish and maintain territories, using small patches of open ground as leks or courtship areas. If they’re lucky, the male will be able to guide the female over a spermatophore. The spermatophore is then deposited on the ground for the female to take up through her cloaca.
The larvae hatch anywhere from two to five weeks later, and the development of forelimbs begins before the back legs. Right before they go onto land, the larvae absorb their external gills; at this stage, they can reach a size of up to 7 centimeters. The metamorphosis from water to land efts generally occurs two to four months after hatching depending on the temperature.
The northern crested newt is an impressive creature, sporting several distinct features that set it apart from other newts. Although its populations are in decline, we can all do our part to help conserve this species by limiting human activity in their natural habitats.