structural:scholar_edition
Hummingbirds

Hummingbirds are the main pollinators of heliconia flowers in many locations. The concurrent diversification of hummingbird-pollinated taxa in the order Zingiberales and the hummingbird family (Trochilidae: Phaethorninae) starting 18 million years ago supports the idea that these radiations have influenced one another through evolutionary time. At La Selva Research Station in Costa Rica, specific species of Heliconia were found to have specific hummingbird pollinators. These hummingbirds can be organized into two different groups: hermits and non-hermits. Hermits are the subfamily Phaethornithinae, consisting of the genera Anopetia, Eutoxeres, Glaucis, Phaethornis, Ramphodon, and Threnetes. Non-hermits are a catch-all group of other hummingbirds that often visit heliconias, comprising several clades (McGuire 2008). Hermits are generally traplining foragers; that is, individuals visit a repeated circuit of high-reward flowers instead of holding fixed territories Non-hermits are territorial over their Heliconia clumps, causing greater self-pollination. Hermits tend to have long curved bills while non-hermits tend to possess short straight bills, a morphological difference that likely spurred the divergence of these groups in the Miocene era. Characteristics of Heliconia flowers that select for either hermit or non-hermit pollinator specificity are degree of self-compatibility, flowering phenology, nectar production, color, and shape of flower. The hummingbird itself will choose the plants its feeds from on the basis of its beak shape, its perch on the plant, and its territory choice.

Hummingbird visits to the Heliconia flower do not affect its production of nectar. This may account for the flowers not having a consistent amount of nectar produced from flower to flower.

Different Heliconia species have different flowering seasons. This suggests that the species compete for pollinators. Many species of Heliconia, even the newly colonized species, are visited by many different pollinators.