Hormonal control of birth behavior in the bandicoot (Perameles gunnii: Marsupialia) and other marsupials.

The barred bandicoot is a small marsupial, locally common on the island of Tasmania, Australia. Several marsupial species have been shown to respond to injections of prostaglandin F2alpha or oxytocin by demonstrating birth behavior but that if an inhibitor of prostaglandin synthesis was given prior to oxytocin, no birth behavior was demonstrated. The barred bandicoot has behaved in a similar manner, demonstrating a significant increase in grooming and three other behaviors (crouching/prone, lateral and 'birth') were only seen after injection of PGF2alpha or oxytocin. The fact that after injection of oxytocin there was an increase in the latency till a birth response confirms a previous finding in another species. Subsequently, we have repeated these experiments with other marsupial groups, with similar results, which suggest that prostaglandin F2alpha stimulates birth behavior and oxytocin stimulates prostaglandin production in most marsupials.