Over the millennia, plants have developed a variety
of means to get pollinated. Whereas, wind may be good enough for some, others
use insects, bats or birds for more reliable results. Color and odor are
employed as indicators of where the pollinators should come and the reward for
a good job done is, invariably, a good drink of nectar.
South Africa’s Western Cape has an impressive
variety of flowering plants, all of which need pollinating. One species, Babiana ringens or Rat’s Tail has large
flowers at ground level. It gets its common name Rat’s Tail because it has a
strong sturdy spike growing alongside the flower. It has to be sturdy because
it is the perch for the pollinator to come and do the business (1,2).
The pollinator is the Sunbird and he hangs upside
down on the Rat’s Tail and sucks up his reward through his long beak. I say
‘he’ because the males get to the nectar bar much more often than the females
do and, what is more, spend a lot longer drinking as well.
Some of the varieties of B. ringens can manage to self-pollinate, others can’t and rely
completely of their Sunbird customers who spend a lot of time visiting one or
other of the chain of Rat’s Tail Bars that are doing well on the Cape. Even the
varieties that can manage on their own welcome help from thirsty Sunbird
customers.
As the Bars are only available to Sunbirds, I
suppose we should think of them as exclusive Clubs and not compare B.ringens with the more promiscuous
behavior seen on many, many other flower species occupying more common or
garden habitats.
- http://aob.oxfordjournals.org/content/early/2011/08/10/aob.mcr172.abstract
- http://www.bbc.co.uk/news/science-environment-14788701
