A group of biologists from the University of Antioquia investigates the factors that underlie the charm of this winged figure that flutters throughout Colombia.
science academy
summer
Surely at some time your gaze has gone away after the flight of a hummingbird. Their colorful presence and fast flight are part of the grace that covers them. Its iridescent clothing has an evolutionary history of more than twenty-three million years in which it has been related to different types of plants from which it extracts its nectar for its survival. An analysis of the itineraries or routes established to reach their floral destinations allows the categorization of generalist species —those that visit many flowers— and specialists —dedicated to some—.
Biology suggests that the shapes of the beaks, essential for their feeding, evidence the interactions between the bird and the flowers. They are long, short, curved and straight, traits that depend on several factors: «There are certain correspondences between the shape of the beak and the flowers that hummingbirds visit. For example, in the lowlands there are many species with long, curved beaks that feed on the flowers of the platanillos (heliconias); the long, curved spikes limit the type of flowers they can visit. Usually, the extremes restrict the variety of flowers that can be used, such as the Pico de Sable species, whose beak is longer than the body,” explained Juan Luis Parra Vergara, researcher member of the Vertebrate Ecology and Evolution group, attached to the Faculty of Exact and Natural Sciences.
Because they are nectarivores —they feed on nectar— and pollinators —pollen carriers—, hummingbirds are responsible for the variety of plant species that occur in their territories. Some researchers from the Institute of Biology have wondered about this relationship between floral morphology and the structure of the beak —length and curvature— based on an observational study of two species: Phaethornis syrmatophorus and Haplophaedia aureliae, and of the plants Centropogon trianae, Columnea purpurata and Besleria solanoides in the Alto de San Miguel Regional Protected Forest Reserve in Caldas, Antioquia.
«We carried out an observational study that consisted of estimating the frequency of visits of these species to these plants. We found that the greater the similarity between the length and curvature of the flower and the beak, the greater the frequency of visits, and that this similarity favors the pollen load,” explained Sara Moncada, a graduate of the Institute of Biology of the University of Antioquia.
These birds, also known as hummingbirds, inhabit ecosystems ranging from mangroves to savannahs or moors in America. In Colombia there are 165 species, of which 72 fly in Antioquia and 26 in the Aburrá Valley. They are found in all climates and territories, especially in the Andean zone, although their presence is more limited in places where there is little water, such as cities.
The Vertebrate Ecology and Evolution group has developed a large part of its investigations in the aforementioned reserve of Caldas, an ecosystem in which the native and recovering forest stands out, which favors the sighting of different species that make up its avifauna, including hummingbirds. They have also studied them in the areas of influence of Hidroituango and in páramos such as Belmira.
ornament on the feathers
The charm of these birds is also determined by their plumage of various colors that have captured the attention of biologists and have led many to call them “winged jewels”: “The color results from the interference of a structure that they have in their feathers and the sunlight. To understand it, it is enough to refer to the moment in which one bathes or plays with bubbles: these types of tones and colors are reflected in them. Hummingbirds have structures in their feathers that cause the same effect as bubbles, with the difference that they do not have one layer, but multiple and organized ones, which causes the reflection to be much more intense. Many birds have that type of coloration, but in hummingbirds it has diversified much more,” said Parra Vergara.