The Birrin are an egg laying species, and clutches typically contain 3 or 4 eggs which hatch within days of each other to reveal small, hungry and fuzzy chicks.
The young birrin have several adaptations evolved to aid their survival in the humid and life filled swamps in which the species first evolved. The short hair covering their small bodies is a dense mat of fibres designed to keep the myriad nest parasites from gaining access to their skin, while the conspicuous stripes allow birrin parents to immediately locate their young on foraging trips. This fur, while useful, poses an overheating problem in the tropical climate and so the undersides of the large dorsal ‘wings’ are highly vascular and by holding them out from the body the young can cool themselves.
The fur is shed in stages, first falling away from the lower limbs to prevent mud from the wet forest floor fouling the fibres.
The other major adaptation youthful birrin possess are large patterned plate-like growths around the base of each eye stalk, and covering part of the breathing apparatus: These plates not only help deny access to certain parasites but are also used to elicit feeding behaviour from the adults when displayed around the open mouth.
Most modern birrin, having long since industrialised, rarely brood traditionally but often use communal incubators or hired nannies to warm eggs during gestation. Indeed the fur, once useful for parasite control, is now a hindrance in the hot modern climate of Chriirah and in some regions is shaved off soon after birth to keep the chicks cool.
Depicted here are two young birrin recently out of the nest and already engaging in the boisterous play behaviours that will prepare them for their often dynamic, active lives.