Ecuador harbors unique species and ecosystems, many of them endemic and threatened. This is the case of the Black-breasted Puffleg, Eriocnemis nigrivestis, a hummingbird only known from Andean forest of Ecuador (3000 – 3500 m) at two localities, in Pichincha and Imbabura provinces. This species inhabits the interior of well-conserved montane forest and ridge-crest dwarf forest with abundant shrubby Ericaceae vegetation, bromeliads and orchids. Habitat loss and climate change are the species main threats. In order to design adequate conservation measures for the Black-breasted Puffleg we study the species natural history and describe plant-hummingbird interaction networks associated with the Puffleg. By describing these interaction networks we are able to determine which species of plants are critical in the diet of this hummingbird.
This knowledge is relevant for conservation, especially in systems harboring highly threatened species. We described plant-hummingbird networks during two years at three 1.5 km transects (Verdecocha, Yanacocha, and Alaspungo reserves), located at the north western flanks of the Pichincha Volcano where the species have been recorded previously. We placed 12 time-lapse cameras every month on each transect where we also conducted monthly flower census. We quantified species level metrics such as closeness (i.e., do species share resources with many other species), and betweenness (to what extent a species interact across otherwise unconnected parts of the network). The Black-breasted Puffleg was recorded only at Verdecocha, along with other 10 hummingbird species. The Puffleg was recorded in 390 of the 3000 interactions we registered at Verdecocha. It feeds on 16 out of 41 filmed plant species.
The most frequently visited plant species were Macleania rupestris (Ericaceae), Guzmania bakeri (Bromeliaceae) and Palicourea fuchsioides (Rubiaceae The Black-breasted Puffleg had rather low values of betweeness (0.03 ± 0.01 SD) compared to the community mean (0.09 ± 0.01 SD), and values of closeness (0.1 ± 0.02 SD) close to the community mean (0.09 ±0.02 SD). These figures suggest that even though the Black-breasted Puffleg is not a core species in the plant-hummingbird network at Verdecocha, it interacts with a relatively large proportion of species as compared to other species in the community, therefore it might have an important role in the maintenance of the network structure. Thanks to this project we increased our knowledge of Puffleg foraging behavior and showed that the use of time-lapse cameras is efficient methodology for studying rare and threatened species (Figure 1). We also learned, that although Black-breasted Pufflegs have been reported to feed on the flowers of a wide variety of plant species, they concentrate feeding on a subset of these plants. This information has been translated into conservation actions by implementing a greenhouse in a local community where a group of women are in charge of the propagation of 30 plant species that were identified as important for the Pufflegs as well as other hummingbirds. At the moment at least 5000 native plants have been sown in an effort to restore and enrich disturb habitats in the distribution range of this threatened species.
Figure 1. Male Black-breasted Puffleg feeding on Guzmania bakeri and researcher Tatiana Santander captured on a time-lapse camera.