Partial replacement of Rainbow Lorikeets Trichoglossus haematodus moluccanus by hybrid lorikeets in Hobart, Tasmania

Abstract

The Eastern Rainbow Lorikeet Trichoglossus haematodus moluccanus recently became established in Tasmania. This study presents opportunistic observations of the species in Hobart from March 2007 to August 2018. During the first 6 years, flocks of more than four Rainbow Lorikeets were seldom seen. However, during the middle of 2013 larger flocks of up to 14 birds were observed repeatedly. Following this, five birds were trapped and removed in August 2013 and another four in May 2014. Thereafter, only five observations of more than a single Rainbow Lorikeet were made, suggesting that trapping may be effective at controlling their populations locally. However, following the trapping sessions, apparent hybrids between Rainbow Lorikeets and native Musk Lorikeets Glossopsitta concinna became more common and more diverse in appearance. Four morphotypes of hybrids were observed, with one of these almost certainly the result of interspecific mating in the wild. Rainbow Lorikeets and hybrids foraged predominantly from flowers of Swamp Gum Eucalyptus ovata and at bird-feeders. Hence, Rainbow Lorikeets could possibly have impacts on Musk Lorikeets through interbreeding and, if they become more common, on these and other species of birds through competition for nectar and pollen of eucalypts.