Duration, Persistence and remaining mysteries in the maternal behaviour of platypus (ornithorynchus anatinus). (#900)
The breeding of platypus (Ornithorynchus anatinus) in captivity proved difficult for many years but with improvements in husbandry and greater understanding of platypus biology there have been recent successes at two institutions. Detailed video camera monitoring of the three successful breeding events at Taronga Zoo identified breeding markers and revealed a consistency of maternal behavioural patterns. After mating and nest-building, the female retired (Day 0) to the burrow to lay and incubate the eggs; during this estimated 15 day incubation period she did emerge briefly (for 0.3-1.1hr) to wet herself and groom. The suckling period was of long duration, 110-123 days, at the end of which the juveniles were approaching adult female weight. The duration of maternal absence from the burrow increased from 1hour/day after hatching to stabilise after 37-50 days at a mean of 34±5hrs, whereas the duration of burrow visits was stable (mean 14±5hrs) from day 20. Juvenile emergence occurred between 128-132 days after retirement. In the week prior, maternal burrow visits became more variable and short (mean 5±3hrs/48hrs) but at emergence the pattern changed, the female stayed in the burrow (mean 18±4hrs/day) for up to 7 days. After emergence the juveniles, though foraging independently, all made concerted efforts to regain the burrow. This indicated investment in some on-going maternal care. The activity overlap in pools varied after emergence and female-juvenile interactions were observed. Mysteries still remain in the details of platypus parental care – the relocation and re-positioning of eggs and young in the burrow, how the growing young adapt to the hypoxia and long term confinement of the nesting chamber – solutions must await video access the platypus nesting chamber.