Smooth Newt - Life Cycle

Life Cycle

Adult Smooth Newts emerge from hibernation on land from late February to May, and head to fresh water to breed. They favour ponds and shallow lakesides over running water. At this time both sexes of newt become more strikingly and colourfully marked, with vivid spots and orange bellies. The male also develops a wavy crest along the back and tail - the sexes are much easier to differentiate during the breeding season.

During courtship the male newt "displays" for his prospective mate by vibrating his tail in front of the female in a distinctive fashion. The male then deposits a sperm-containing capsule, known as a spermatophore, in front of his mate, who manoeuvres herself into a position whereby she can pick up the capsule with her cloaca - fertilization occurring inside the female. The female, thus fertilized, after a few days starts to lay eggs individually, usually under aquatic plant leaves at a rate of 7 to 12 eggs per day. Altogether, a total of 400 eggs may be produced over the season.

After two to three weeks (depending on water temperature), the eggs hatch to a larval form - a tadpole. For a few days the tadpoles live off the food reserves contained within their yolk sacs (left over from the egg stage). After this they start to eat freshwater plankton, and later insect larvae, molluscs and similar food (unlike frog tadpoles, newts are carnivorous throughout their life).

The newt tadpoles look initially like small fish fry, but later become more similar to miniature adults, but with "feathery" external gills emerging from behind the head on either side. As the tadpoles mature they develop legs (front first), and the growth and use of their lungs is matched by a gradual shrinkage of the gills. Thus the tadpole gradually shifts from being fully aquatic to possessing a body suitable for a mostly terrestrial existence, a tadpole typically leaving the water after ten weeks.

Some tadpoles however may overwinter in the larval state, only emerging from the water the following year. Smooth Newts take around three years to become sexually mature, on average living for six years. Most adult and juvenile newts hibernate over winter in moist sheltered areas above ground, emerging in the spring.