Scientists believe baby turtles can communicate with each other before they hatch – and can arrange to emerge from their eggs at the same time.
A study of Australia’s Murray short-necked turtle found the embryos synchronised their hatching to prevent smaller turtles emerging alone and being attacked by predators such as goannas and foxes.
It is believed the unhatched turtles, which lie enclosed in a tight nest, may be able to sense each other’s heart vibrations or may detect gases emitted from the breath of other turtles. In this way, more developed turtles can send signals on their growth status to less developed ones to encourage them to increase their growth rates.
The researchers, from the University of Western Study, said that embryos positioned at the bottom of the nest – where temperatures are lower – have a “catch-up mechanism” which enables them to overcome their longer incubation periods.
The researchers studied the turtles by dividing a clutch of eggs into two and incubating them at different temperature levels. They then united the eggs after a week and analysed the embryonic heart rates and metabolic rates. During the last third of the incubation period, the cooler embryos had sped up their heart rate and metabolism and hatched within a couple of days of the warmer ones.