Even Pollinators Gravitate to Certain Colors

Himalayan Blue Poppy

Melbourne: 
Himalayan flowers have evolved to attract bees as pollinators, scientists have found for the first time. The study has implications for understanding the effects of climate change on plant pollination. 

Biologists from Monash University and RMIT University investigated the evolution of flower colors due to the bee's color vision. 

They researched in the understudied Nepalese steep mountainous terrain, and other subtropical environments. 

Associate Professor Adrian Dyer of Monash and RMIT said previous studies had shown that flower color evolved to attract bees as pollinators in temperate environments, but the story for either subtropical or steep mountainous environments had been unknown. 

"Mountainous environments provide an ideal natural experiment to understand the potential effects of changing climatic conditions on plant-pollinator interactions, since many pollinators show preferences for localized conditions, and major pollinators like honeybees do not tend to forage at high altitudes," Dyer said. 

Using computer models to examine flower colors as bees would see them; the team
 addressed how pollinator vision had shaped flower evolution. 

Then, with associate professor Martin Burd, of the Monash University's School of Biological Sciences, they did phylogenetic analyses to identify how altitude zones affected results. 

Shrestha said flowers from both subtropical (900-2000m) and alpine (3000-4100m) regions showed evidence of having evolved color spectral signatures to enhance discrimination by bee pollinators. 

"The finding was a surprise as flies are thought to be the main pollinator in many mountain regions, but it appears that in the Himalayas several bee species are also active at high altitude, and these insects have been such effective pollinators that they have led to the evolution of distinctive bee-friendly colours," Shrestha said. 

The research could shed light on how flower colors may continue to evolve in particular environments, depending upon the availability of the most effective pollinators. 

While 'bee colors' were prevalent at all elevations, flower colors in high altitude zones were more diverse and had more often undergone larger steps of evolutionary change than those at lower elevation, Burd said. 

The study was published in the Journal of Ecology.

Himalayan Blue Poppy

Don't you love it that bees have favorite colors? Butterflies too. BBL