Acerca de
Conservation
Chilean Woodstar Hummingbird, an Endangered Species
written by Lucia Paulina Gonzalez-Gomez
The Chilean Woodstar (Eulidia yarrellii) is a small hummingbird (~2.5g) which occurs in a few oasis-like valleys in the Atacama Desert in Chile. Although the Atacama Desert is the driest in the world, the fertile valleys provide abundant riparian vegetation and stable climatic conditions year-round. Since 2003 the Chilean Ornithologist’s Union (AvesChile), has been monitoring the species’ population size through annual surveys during the reproductive season. With this information, we have detected a steep population decline, from about ~1500 individuals in 2003 to around 300 in 2021. This decline could be explained by several factors, such as habitat destruction which includes burning of riparian vegetation, and the destruction of traditional olive orchards, which this hummingbird uses for nesting. In addition, the intensive agriculture developed in the last decades, includes the intensive use of pesticides, which could largely affect hummingbirds through direct poisoning or indirect contamination of nectar sources. Secondary causes are related to other agricultural practices, and the competition with other hummingbird species, particularly the Peruvian Sheartail (Thaumastura cora), a species that spontaneously colonized the region a few decades ago, and that has steadily increased its population.
As in many hummingbirds, male Chilean Woodstars gather in “leks” during reproduction. This means that males establish territories close to other males where they display courtship dances. Females visit these sites choosing a mate. Evidence suggests that the location of these clusters of males (leks), remains unchanged for many years. In this hummingbird, males present extreme fidelity to their lekking sites. We have observed that even when the habitat in the lek area deteriorates, males remain in their territories, showing an evident behavioral inflexibility. Outside of the reproductive season, from February to August, Chilean Woodstars are rarely detected in the valleys where they are observed during the reproductive season, presumably migrating to the Andean foothills. These behaviors pose conservation challenges. On one hand, protecting the land where these leks or nesting sites exist is extremely difficult considering the high price per hectare driven by agricultural activities. Current regulations severely limit the capacity of Chile’s Government to acquire land for conservation purposes. In addition, although education campaigns are regularly carried on, the high revenue of the intensive agricultural crops discourages the development of sustainable tourism, as a conservation tool.
©Cristian F. Estades
The conservation efforts led by AvesChile have been focused on developing experimental tools to attract males to form new leks in public land areas, which can be protected formally. This includes realistic hummingbird models with sound equipment that can survive the harsh desert conditions. In addition, we have tried to learn what are the main nectar sources that this hummingbird uses and tried to propagate them. We also experimented with artificial feeders and learned that this hummingbird is mostly reluctant to use them. Keeping the population surveys during the breeding season has been crucial, and an additional post-breeding estimation has been added during the past years, trying to understand the habitat use and migratory patterns of this rare hummingbird. With this information, AvesChile has been able to inform the government about the population decline and propose conservation areas, although their response has been extremely slow. Sadly, under the current conditions we think that conservation efforts need to be dramatically intensified. Otherwise, shortly we will see the Chilean Woodstar hummingbird going extinct.
©Cristian F. Estades
©Cristian F. Estades