Some brooding parents take it in turns to care for their clutches, but not pythons. The majority of python mums spend the entire incubation alone, wound around their precious eggs. These mothers protect their clutches from predators and keep the eggs warm in their coils. However, they can also restrict their young's access to oxygen if they clasp too tight, so they periodically relax their grip to improve the eggs' oxygen supply. The developing young are also supplied with all of the water that they will need during development when the egg is laid, but this places the egg at risk of dehydration when conditions are dry. Knowing that incubating python mums adjust their postures to make sure that their young don't suffocate, Zachary Stahlschmidt and Dale DeNardo from Arizona State University wondered whether they also change position as environmental humidity fluctuates to protect their eggs from dehydration. The duo monitored the behaviour of eight incubating Children's python mums as the temperature cycled between 31.5°C and 26°C at low, medium and high humidities (p. 1691).

Monitoring the snakes' posture and the clutches' temperature and humidity, the duo found that when the air was humid and moist, the mums didn't seem concerned about water loss. They loosened their coils when their eggs were warm and curled them tight when the temperature fell to keep the eggs warm.

However, when the air was dry, the mothers spent significantly more time coiled tightly around their eggs. Even when the clutch was warm, and the mothers could have relaxed their coils, they kept them tightly wound to protect their young from dehydration.

So python mothers adjust their coiling behaviour in response to humidity and temperature to protect their unhatched young from dehydration and give them the best start in life.

D. F.
Parental behavior in pythons is responsive to both the hydric and thermal dynamics of the nest
J. Exp. Biol.