A pair of Canadian researchers found themselves upstaged by hummingbirds while attempting to hand pollinate ecologically significant plants in Costa Rica.
Heliconia are native to tropical America and islands of the Pacific. Close relations of banana plants, Musa, they are popular as tender ornamentals with large leaves and large brightly coloured bracts. Over a hundred species are known along with numerous cultivars.
In Costa Rica,
Heliconia tortuosa with its showy red and yellow blooms is regarded as a ‘keystone” species in the ecological web. This drew the attention of two Canadian scientists, both originally from New Brunswick: Adam Hadley, now a postdoctoral researcher at the University of Toronto, and Matthew Betts, an associate professor at Oregon State University.
They wished to discover if deforestation was affecting the relationship between the
H. tortusoa and the hummingbirds that pollinate them. In part, this investigation involved their hand pollinating the bloom – except it barely worked. However, the
Heliconia cooperated with hummingbirds. Later research determined that two species in particular, the green hermit hummingbird and the violet sabrewing hummingbird, are especially effective. Their long, curved beaks reach deeper into the blooms than those of other hummingbirds – and the plants appear to recognize this.
“It’s pretty interesting,” said Hadley. “It’s almost like decision-making behaviour.”
The plants respond by allowing the pollen to germinate, ultimately increasing the chances for successful seed formation, the researchers explained in the journal
Proceedings of the National Academy of Sciences. Being picky may increase access to genetic diversity and thus give the plants a competitive advantage over their neighbours.
“We’ve sort of almost thought about it as some kind of hummingbird foreplay that’s required,” concludes Hadley.
