A new study has shown that hybrid birds were more likely to fight off diseases than were pure breeds; an example of the biological phenomenon of heterosis, in which a crossbreed is stronger than its two purebred ancestors. Scientists from the Centre for Integrative Ecology at Deakin University in Geelong, Victoria, studied the infection patterns of beak and feather diseases in crimson rosellas across southern Australia. This included several hybrid populations in northeastern Victoria and southern New South Wales, located in between the range of the two parent subspecies. ("Platycercus elegans flaveolus" and "P. elegans elegans"). They found that when the subspecies mated, the resulting offspring seemed to cope better with a potentially deadly virus.