Insects are not the only creatures that transport pollen from one flower to another, thereby helping them to reproduce. As we have already mentioned in a previous article (“Lizards and their positive footprint on oceanic islands”), vertebrates such as lizards can also be important pollinators, particularly in oceanic islands. Birds also play a very important role and are responsible for the pollination of numerous plant species.
Eurasian Blue Tit (Cyanistes caeruleus) with grains of pollen adhered to the feathers on its head. Photo: Alejandro González
Flowers that attract birds tend to have quite distinctive characteristics, such as bright red petals, a considerable amount of nectar or a total lack of perfume. The best-known pollinators are hummingbirds (Trochilidae), found primarily in Central and South America, although in actual fact we can find birds that specialize in sipping nectar from flowers in every continent except Europe. Nonetheless, even in this continent, pollination by birds does also occur, although less often than elsewhere and the birds that do so have other sources of nutrition as well as nectar from flowers (they are not exclusively nectarivores).
Bicácaro (Canarina canariensis)
An example that we can find close to home, and a very eye-catching one at that, is the Canary Islands’ very own (Canarina canariensis). This plant attracts visits from such birds as the chiffchaff (Phylloscopus canariensis), the Eurasian blue tit (Cyanistes caeruleus) or the Eurasian blackcap (Sylvia atricapilla), Sardinian warblers (S. melanocephala) and Spectacled warblers (S. conspicillata). Other examples of Canary Island plants that are visited by birds are the Canary Island foxglove (Isoplexis canariensis) and Parrot’s Beak (Lotus berthelotii).
Parrot’s Beak (Lotus berthelotii). Photo: Alejandro González
Canary Island foxglove (Isoplexis canariensis)
When birds approach flowers in order to consume their nectar, they enter into contact with the stigma and the stamens (the male and female reproductive organs), in such a way that the grains of pollen adhere to their beaks and to the feathers on their heads, and are then transferred to the stigma of a different flower. Once again, we see how this beneficial process of “natural cooperation” allows birds to benefit from the nutrients they obtain from sipping nectar from flowers, while at the same time ensuring their reproduction.
Beatriz Rumeu
Recommended reading:
da Silva LP, Ramos JA, Olesen JM, Traveset A, Heleno RH (2014) Flower visitation by birds in Europe. Oikos, 123, 1377-1383.
Rodríguez-Rodríguez MC, Valido A (2008) Opportunistic nectar-feeding birds are effective pollinators of bird-flowers from Canary Islands: experimental evidence from Isoplexis canariensis (Scrophulariaceae). American Journal of Botany, 95, 1408-1415.