7 amazing facts about Harpy Eagles

Harpy Eagle

Of all the iconic species one has a good chance of encountering on Eagle-Eye Tours’ Guyana Birding Tour surely the most impressive – as in “awesome” – is the Harpy Eagle. Certainly not the weirdest species (- that prize goes to either the Hoatzin or the Capuchinbird) nor the most beautiful (Guianan Cock-of-the-Rock?), but a Harpy Eagle sighting always adds that “wow” factor to any trip. The Eagle-Eye Tours 2022 tour produced the best Harpy viewing experience in the seven visits I’ve made since 2013. The boat trip along the Burro-burro river to reach the nest location is a tale for another time but sitting in our motorized “canoe” watching the pair feeding, bonding, etc., at their enormous nest was the most exciting ½ hour of all my Guyanese adventures.

But what is it that places this species so high up on every birder’s wish-list? Eagles are always pretty spectacular but this one in particular beats just about every other eagle in the awesomeness stakes. Here are a few facts that perhaps help to explain why:

1. They’re HUGE!! But this does need some qualifying: since the species is primarily a forest species its wingspan is actually somewhat less than a few of the longer-winged open-country species. Golden Eagles, for example, can have a wingspan in excess of 7.5ft whereas Harpys measure in at 6.5ft. But a female Harpy can weigh a massive 20lb compared to the 15lb Golden. Only Steller’s Sea-eagles attain that same 20lb mark – held aloft by an 8.3ft wingspan!
2. They habitually prey on relatively large mammal prey species – sloths, howler monkeys, capuchin monkeys – mostly snatched out of trees. The species has been known to take even fully adult howlers of weights in excess of 13lb (only reported on 2 occasions) – that’s close to the weight of the aforementioned Golden Eagle!
3. Their enormous nests are placed in the crowns of true forest giants (e.g. in Ceiba and Mora) – super-canopy trees that reach heights of considerably more than 160ft! Searching the Internet, nest-size is indicated as equivalent to a double-bed. This seems about right given the couple of structures I’ve seen – but then dimensions are given elsewhere as about 52” which is just a little shy of a double-bed’s width. Still pretty big though.
4. Incredibly, this massive tropical raptor was considered “not uncommon” on the Caribbean slope of southern Mexico, as recently as the 1940s! The species’ population status further south in Central America seems pretty shaky with very, very few recent records from Costa Rica. Nevertheless, and fittingly, Harpys still breed in Panama where the species has been adopted as the national bird, crowning the Panamanian coat of arms.
5. The young Harpy can take up to 5 or 6 months to fledge, and even then the “teenager” hangs around the house for another year, continuing to be fed by its parents! This goes a long way to explaining why the adults breed only once every 2 or 3 years!!
6. Harpy’ feet are massive – this being the death-dealing part of the bird. The feet are the size of a large human hand and are equipped with formidable talons – the rear talon can measure between 4 and 5 inches, the same size as the claws of a Grizzly!
7. Named after the harpies of ancient Greek mythology – the wind spirits that took the dead to Hades. Googling “harpies” I came across the following apt passage regarding their place in Greek mythology: “When a person disappeared from the Earth, it was said that he had been carried off by the harpies”. Obviously, Howler Monkeys and Sloths throughout South America can relate to this pretty well.

Harpy Eagle pair © Paul Prior

Overall, then, all of this is in keeping with the legendary status of these magnificent birds. In January 2022 our small Eagle-Eye group lucked in on the very best of encounters; our timing was perfect: junior had left the previous year and the adults were readying themselves for the start of another cycle. By now, assuming the copulation we observed in January was successful, there should be a young eagle being fed at the nest, looking to make its first flight in the next month or so. From then on, timing suggests that the youngster will hang out in the vicinity of the nest, the parents returning with prey items every couple of days until next summer.

This latter scenario is consistent with all of my previous encounters with the species at a different nest site many miles to the west of the 2022 location. Few things in nature viewing can be guaranteed but Eagle-Eye Tours has an excellent team based in Surama, and if anyone knows where the most likely active nests are at any particular time (and, as importantly, readily accessible) it is this group.

Harpy Eagle nest © Paul Prior

Personally, for January 2023 I’m already pretty excited at the prospect of revisiting either one of the nest sites I’m now familiar, or perhaps the locals will come up with another alternative location. As with any of Eagle-Eye’s tours anywhere in the natural world, one just never knows, but one definitely increases the chances of magical encounters with legendary birds like the Harpy Eagle by just being out there. Join Eagle-Eye Tours Guyana Neotropical Wilderness Birding Tour.