Breeding

Male Combat Western Taipan
Photo: Peter McCrae EPA

Male Combat Western Taipan
Photo: Peter McCrae EPA

Western Taipan Eggs
Photo: Charles Tanner

Western Taipan Hatchlings
Photo: Charles Tanner

Most snakes breed during Spring. The reproductive cycle starts with males searching for mates, followed by mating. In due course, young are born or hatch from eggs.

Males of many species engage in combat during the breeding season. This complicated and ritualised test of strength may last from a few minutes to more than an hour. The snakes intertwine their bodies and raise their heads, each repeatedly attempting to climb higher than the other until they topple over. Snakes that engage in combat include Carpet Python, Keelback, Marsh Snake, Red-bellied Black, Black Whip Snake, Eastern Brown and the Coastal Taipan.

Mating is relatively passive. Males find partners by following chemical signals (pheromones) left by females. Contact begins with a series of gentle bumps, side brushes and nudges. Copulation is slow and repeated with the partners lying side by side or slightly intertwined. The ‘penis’ of the male is a distinctive, ornate, paired organ (hemipenes).

Snakes are usually solitary. They mate and move on. Some may live communally for short periods. An aggregation of hundreds of Carpet Pythons, Common Tree Snakes and Brown Tree Snakes has been reported from tree hollows south of Gympie. Communal nesting has also been reported. A cache of about 600 eggs, laid by Yellow-faced Whip Snakes, was reported from a road cutting, also from near Gympie, in 1972.

Most snakes are egg layers. Of the 31 species of snakes occurring in the Brisbane region, 21 species lay eggs, with the remainder bearing live young.

Once a female snake has laid eggs or given birth, she usually has no contact with her young, although some snakes, for example Red-bellied Black Snakes, occasionally prey on their own young.

Pythons are unusual amongst snakes in caring for their eggs. A female will coil round, guard and incubate her eggs for 2-3 months. As the sun rises, she will leave them to bask. When shade envelops the eggs they cool and the female, now warm, returns and wraps herself around them. She will, when necessary, increase her body heat by 'shivering'. A female Carpet Python will defend her eggs with vigour.