title: Effect of melatonin and removal of pouch young on the seasonality of births in the marsupial possum, Trichosurus vulpecula.
abstract: Melatonin implants were placed in 5 adult female possums during December. Births were observed from 31 March to 12 April in 4 control possums, and on 16 January, 1 and 6 February, 27 March and 27 April in the melatonin-treated animals. Melatonin would appear to have advanced the start of the breeding season in 3 of the 5 animals. Following removal of pouch young a subsequent birth is more likely to occur when young are removed early in the breeding season. These results would suggest that daylength may play a role in the initiation of the breeding season and the stimulus to mate diminishes from March through to September. Nevertheless, if the environmental conditions are favourable a secondary peak of births can occur in the later part of the year.
mesh_terms: D000818:Animals; D005260:Female; D007743:Labor, Obstetric / Q000187:drug effects*; D008394:Marsupialia / Q000502:physiology*; D008550:Melatonin / Q000494:pharmacology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D012621:Seasons
chemical_list: D008550:Melatonin