The harpy is the world’s largest and fiercest eagle, but also the least known. To save this elusive bird from extinction, you must first find and catch it. This dangerous mission is not for the faint-hearted, as Pete Oxford discovered when he joined scientists in the Amazonian canopy.
We sloshed with unsteady footfalls, waist-high in water, towards the Gothic buttress roots of a giant kapok tree. From the bromeliad-covered branches above came the plaintive cries of Pacuyo, a seven-month-old harpy eagle.
The harpy eagle is an impressive bird, a supreme predator of monkeys and sloths, which it snatches from the branches using its ferocious talons. Yet little is known about it.
Though the species ranges as far north as southern Mexico and as far south as south-east Brazil and northern Argentina, it is rare and in decline everywhere due to habitat loss and poaching for its talismanic feathers. Even in well-populated areas, such as here in Ecuador, nests are very hard to locate.
So, lucky enough to have tracked one down, our next mission was to attach a GPS to Pacuyo’s back, which would allow his movements to be monitored for the next three years. Today marked our ninth attempt to fit the harness, and if we succeeded, it would be the first time a harpy eagle had been tagged in this way.
Pacuyo was already able to fly, so we had to capture him remotely using a foot-noose trap. This comprised a wire mesh baited with a dead sloth ‘stolen’ from the chick, and a string noose that could be pulled shut from the ground.
Hands on conservation
Ruth Muñiz, head of the Harpy Eagle Conservation Programme, directed the mission from the ground, and Alexander Blanco, a Venezuelan vet and tree-climber, assembled the device and was in charge of securing the bird. My job was to take photos and ‘call the trap’ – signal to the team below when to pull the noose shut. The effort required to set the snare and Pacuyo’s nervousness meant that we could only attempt one ‘pull’ per day. We had so far experienced nothing but failure.
Yet our trap had been evolving. Every night we had analysed the day’s images on my laptop, and learned exactly why each pull had failed – for example because the noose had only snagged Pacuyo’s talons and not his tarsus (wrist).
Today was our last chance; the culmination of all our efforts. We waited in tense silence as Pacuyo approached the remodified trap. After what felt like hours, he finally lunged for the meat. The noose gently fell across his claws. “Pull!” I yelled, and the rope tightened.
Alex shinnied up to the nest and grabbed the puzzled bird, wrapping his lethal claws in bandages and taping his beak. He then clipped Pacuyo to his climbing harness and scrambled back down.
The team leapt into action, taking data and preparing the GPS ‘backpack’ the chick was to wear. After just 20 minutes, Pacuyo was on his way back to the nest. I climbed up with Alex to record the release, and we carefully unwrapped his feet and beak, and returned his coveted sloth. The youngster accepted the meal with unexpected ease, so we sat and watched him, the sun warm on our backs.
Satisfied that all was well, we headed back to Quito, Ecuador’s capital – only to be greeted by the heartbreaking news that the transmitter had failed due to a technical malfunction. All that hard work had been for nothing!
If at first you don’t succeed…
Nonetheless, 10 months later, we were back. The local Cofán Indians had found and been monitoring a second harpy chick. It was a seven-month-old female on the verge of fledging – the timing was perfect. We observed her for several days, then planned our operation.
This was to be a direct capture. Though she was already as big as an adult male (females grow larger than males), Alex would climb to the nest, grab her and bring her down. And so on day 5, ‘Masakay’ was landed. As with Pacuyo, her measurements were taken and a GPS fitted, then she was returned to her nest. We stayed for a few days to ensure that both Masakay and her parents were unfazed by her new accessory.
This time, the GPS did not fail us. It’s 16 months later, and the device is still working well. Masakay has so far strayed no further than 300 metres from her nest, but we’re expecting a big move soon, as she sets off to find her own territory in the rainforest – unwittingly helping in the conservation of her entire species as she goes.
Read more about the harpy here