New research has shown that certain Australian native flowers have shifted away from using insects as pollinators and evolved their flower colour to the red hues favoured by birds.
In a study published in New Phytologist, biologists from Monash University and RMIT University have shown for the first time that Australian native flowers exclusively pollinated by birds have evolved colour spectral signatures that are best discriminated by those birds.
Dr Adrian Dyer of Monash and RMIT said previous studies had shown that flower colour evolved to attract bees as pollinators.
"We know that some flowers had evolved spectral signatures to suit bee pollinators, but the story for bird-pollinated flowers was not clear," Dr Dyer said.
Lead author and PhD student Mani Shrestha of the Monash School of Biological Sciences collected spectral data from over 200 flowering plants and identified the pollinators as birds or insects. Then with Associate Professor Martin Burd - also of the School of Biological Sciences - did phylogenetic analyses to identify how the flowers have evolved spectral signatures.
"We found that flowers exclusively pollinated by birds had initially evolved to suit insect vision, but more recently the spectral signature of bird pollinated flowers had shifted towards longer wavelengths," Mr Shesthra said
The research showed that rather than just having any type of red reflection, bird pollinated flowers targeted the specific wavelengths that best match the long wavelength tetrachromatic (four colour) vision of many Australian native birds.
"Bird pollinated flowers may have evolved red signals to be inconspicuousness to some insects that are poor pollinators, whilst also enhancing the discrimination of bird pollinators," Mr Shresthra said.
Associate Professor Burd said the work had broad significance for understanding how flower colours have evolved to suit specific pollinators, an
|Contact: Emily Walker|