Harpy eagles are perhaps one of the most impressive and ferocious birds on the planet, with an enormous wingspan of up to 2 meters (6.5 feet) - that’s like wearing Stephen Merchant as wings. These birds do not mess around and they're a serious threat for many species in South America where they flit below the tree canopy snatching monkeys and sloths. Their name is actually inspired by Harpyja, the predatory half-woman, half-bird monster of Greek mythology. Basically, they are some seriously badass birds.
These top-tier predators are also elusive animals, steering well-clear of human settlements. As such, they’ve disappeared from ranges encroached upon by human activity and, at the time of writing, they are listed as “Near Threatened” on the IUCN Red List. However, recent research published in the journal Ecology & Evolution has warned that the Harpy could be in more trouble than we realize.
Led by researchers from the University of Plymouth, UK, the new study suggests that the existing methodology used to assess the population size of the species' is overestimating their distribution. The study combined sightings with environmental data to carry out spatial modeling and analyses that took into consideration the birds’ habitat preferences.
"More than half of all global raptor species have declining populations,” said senior author Dr Robert Puschendorf, Lecturer in Conservation Biology, in a statement. “So, understanding more about where they choose to live and why should be a critical factor when we are looking at how best to go about conserving raptor populations. The type of model we have presented here is lacking for many rare and threatened species, particularly in tropical regions, but can be a cost-effective and rapid way to direct conservation planning for threatened species."
Their model revealed a population estimate that sits at 11 percent below the current estimates published on the IUCN website. There are several factors Harpy eagles favor when selecting a habitat, but the team’s research highlighted climatic moisture as one of the most influential, followed by habitats with a minimum temperature of around 27 degrees Celsius (80.6 Fahrenheit) in the warmest month of the year.
This information can be used to inform areas inhabited by Harpy eagles which may fail to fulfil the required conditions to support these animals. Areas which are predicted to remain stable for their resident Harpies include the center-most part of the Amazon, Guyana, eastern Colombia, and Panama. The researchers urge that in light of this, these areas should be prioritized for future conservation projects centered around Harpy eagles.
"Harpy eagles are difficult to observe and live at low population densities, so there has been limited research into what environmental factors influence their range limits,” said Luke Sutton, a PhD student in the University of Plymouth's School of Biological and Marine Sciences and lead author on the research. “Our study shows that predicted future climate stability will be in core areas with extensive lowland tropical forest habitat. That means habitat loss as a result of deforestation is the greatest threat they face, and conservation plans need to take all of that into account."
