Canarina canariensis (Canary bell-flower)

CC image by Michael Fiegle

You will see this iconic plant of Tenerife scrambling over the banks by the path as we walk down the hillside in Anaga: it seems to be one of few flowers at this time of year, so its bright petals do draw attention to themselves.

It's certainly different from flowers at home: it's almost exclusively visited for its nectar by birds, not insects. It's interesting to note that many 'ornithophilous' species have red, orange or purple flowers like this one - it must be an adaptation that appeals to birds' discerning eyes.

There are other traits of ornithophilous flowers. They have to produce large amounts of dilute nectar to keep their bird visitors happy. They also often lack scent. I guess the latter implies birds tend to locate the flowers primarily by sight, and since the plants don't need to waste energy on smelling attractive, they don't bother.

Having said that, some plants will attract both bird and insect visitors. I don't know if Canarina canariensis has a scent or not. Perhaps you can give it a sniff while you're passing.

Canarina canariensis is pollinated by 'generalist passerine' birds. In fact, there aren't any specialist nectar feeding birds on the island, although on the nearby continent there are many examples. It seems that on islands like Tenerife, birds tend to be opportunistic in their diet and eat a bit of everything - nectar, seeds, insects. This is particularly so in the winter when other sources of food can be scarce. On islands, lizards are known to take nectar too. The Gallotia lizards here certainly make use of the fruits of this species.

Biologists have always been interested in how oceanic islands can act as natural laboratories to examine how adaptations are driven in geographical isolation (think of Darwin and his finches). This species is endemic to the Canary Islands.  This paper by Valido et al. suggests however that C. canariensis's ancestors evolved their ornithophilous traits while still on the mainland. The species' closest relations live in East Africa and are pollinated by sunbirds. Another paper, by Mairal et al. interestingly suggests that all the geological chaos with landslides and eruptions on Tenerife, and the steep geography of Anaga, there may actually be more genetic isolation between populations of bell-flower in different places in Tenerife, than between populations on different Canarian islands.