---
title: "What the sources say about the Harpy Eagle | AnimalTracks.wiki"
description: "45 claims from the Harpy Eagle profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/harpy-eagle-1.webp"
canonical: "https://animaltracks.wiki/animals/harpy-eagle/sources/"
---

# What the sources say about the Harpy Eagle (*Harpia harpyja*)

> 45 claims from the Harpy Eagle profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Harpy Eagle](https://animaltracks.wiki/animals/harpy-eagle/)

## Harpia harpyja (harpy eagle). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Harpia_harpyja/

| The page says | The source says |
| :--- | :--- |
| Apex canopy raptor | Harpy eagles are apex predators of their rainforest ecosystems. |
| Mostly the mid to upper canopy of tropical lowland rainforests, preferring undisturbed forest, from southern Mexico to northern Argentina | found from southern Mexico to the eastern part of Bolivia, southern Brazil, and northern Argentina ... Harpy eagles live in the canopies of tropical lowland rainforests. They prefer undisturbed forests ... They generally are found in mid to upper levels of rain forest canopies |
| is the largest species of eagle, according to Animal Diversity Web | Harpy eagles are the largest species of eagle |
| a body up to 102 centimeters long | a body length that can range from 89 to 102 cm |
| Animal Diversity Web estimates that a healthy wild harpy eagle lives 25 to 35 years | Harpy eagles are estimated to live 25 to 35 years if they remain healthy. (note: ADW's own estimate, attributed and hedged; never stated as fact.) |
| Sloths and monkeys, including howler monkeys, are its main food sources | Harpy eagles' main food sources are sloths and primates |
| Long black crown feathers rise into a crest when the harpy eagle feels threatened, and some have suggested it also raises them to direct sound to its ears | The crown of harpy eagles consists of long black feathers which raise when threatened, though some theorize they also raise them to direct sound to their ears. |
| Harpy eagles range from southern Mexico to the eastern part of Bolivia, southern Brazil, and northern Argentina | found from southern Mexico to the eastern part of Bolivia, southern Brazil, and northern Argentina |
| dangerLevel: Low | the eagles overall have no adverse effects on humans (note: task #799; no cached source describes a harpy eagle injuring a person. The talon force (SDZ) is described on prey only.) |

## Harpy Eagle. San Diego Zoo Wildlife Alliance.

https://animals.sandiegozoo.org/animals/harpy-eagle

| The page says | The source says |
| :--- | :--- |
| Apex canopy raptor armed with rear talons larger than a grizzly bear's claws | curved, back talons are larger than grizzly bear claws at 5 inches (13 centimeters) long! |
| Sloths and monkeys, including howler monkeys, snatched from the canopy, plus opossums, porcupines, and iguanas | uses its great talons to snatch up monkeys and sloths ... A harpy also feeds on opossums, porcupines, young deer, snakes, and iguanas. |
| Rear talons about five inches long, larger than a grizzly bear's claws, that the San Diego Zoo says can exert several hundred pounds of pressure, crushing bones and killing prey instantly | curved, back talons are larger than grizzly bear claws at 5 inches (13 centimeters) long! ... The deadly talons of a harpy eagle can exert several hundred pounds of pressure (over 50 kilograms), crushing the bones of its prey and instantly killing its victim. (note: SDZ's own claim, no study cited on the page; attributed to SDZ rather than stated as a measurement.) |
| The San Diego Zoo puts females at 6.3 to 9 kilograms and the smaller males at 3.8 to 5.4 kilograms | female is larger than male Weight: Female, 14 to 20 pounds (6.3 to 9 kilograms); male, 8.5 to 12 pounds (3.8 to 5.4 kilograms) (note: Final pass: replaced ADW's older averages (males 5 to 8 kg) with the current SDZ ranges, which disagree on males.) |
| a wingspan reaching up to 2 meters (6.5 feet) | wingspan, which can reach up to 6.5 feet (2 meters) across |
| Its curved rear talons are about 13 centimeters (5 inches) long, which the San Diego Zoo says makes them larger than a grizzly bear's claws | curved, back talons are larger than grizzly bear claws at 5 inches (13 centimeters) long! |
| they sit on legs as thick as a small child's wrist | The harpy eagle's legs can be as thick as a small child's wrist. |
| The San Diego Zoo describes talons that can exert several hundred pounds of pressure, enough to crush the bones of their prey and kill it instantly | The deadly talons of a harpy eagle can exert several hundred pounds of pressure (over 50 kilograms), crushing the bones of its prey and instantly killing its victim. (note: SDZ's own claim, no study cited on the page; attributed to SDZ rather than stated as a measurement.) |
| A harpy eagle never soars over the top of the rainforest. It flies below the canopy instead | You will never see a harpy eagle soaring over the top of a rainforest. Instead, the powerful harpy flies below the forest canopy |
| in a serious chase it is capable of reaching 80 kilometers per hour (50 mph) | capable, in a serious chase, of reaching speeds of 50 miles per hour (80 kilometers per hour) |
| Its eyesight can pick out something under 2 centimeters across from almost 200 meters away | can see something less than 1 inch (2 centimeters) in size from almost 220 yards (200 meters) away |
| a harpy eagle will perch silently for up to 23 hours, waiting to catch unsuspecting prey | perches silently for hours—up to 23!—in a tree, patiently waiting to catch unsuspecting prey |
| the San Diego Zoo says the monkeys and sloths it snatches from the branches can weigh up to 7.7 kilograms (17 pounds) | uses its great talons to snatch up monkeys and sloths that can weigh up to 17 pounds (7.7 kilograms)! |
| A separate set of smaller face feathers forms a disc that the San Diego Zoo says may focus sound to improve hearing, similar to owls | Some smaller gray feathers create a facial disk that may focus sound waves to improve the bird's hearing, similar to owls. |
| harpies usually build 27 to 43 meters (90 to 140 feet) above the ground, favoring silk-cotton (kapok) trees with widely spaced branches for a clear flight path | For nesting, harpies favor silk-cotton trees (kapok trees) and usually build nests 90 to 140 feet (27 to 43 meters) above the ground. They like to use trees with widely spaced branches for a clear flight path to and from the nest. |
| Most of its food comes from the canopy and understory rather than the forest floor | Most of the harpy’s food is found in the rainforest canopy and understory instead of on the forest floor. |
| The San Diego Zoo says the larger females tend to take sloths and monkeys, which can weigh up to 17 pounds (7.7 kilograms), while the smaller males take more small prey | monkeys and sloths that can weigh up to 17 pounds (7.7 kilograms)! ... The larger females tend to take sloths and monkeys; the smaller, more agile and faster males tend to take more quantities of smaller food items. |
| It also lists opossums, porcupines, young deer, snakes, and iguanas as prey | A harpy also feeds on opossums, porcupines, young deer, snakes, and iguanas. |
| Prey too heavy to carry whole to the nest is taken to a stump or low branch and partly eaten there | Heavier prey is taken to a stump or low branch and partially eaten, since it is too heavy to be carried whole to the nest. |
| The San Diego Zoo says that despite a wingspan of up to 2 meters (6.5 feet), harpy eagles move through their forest home with great agility | Despite their wingspan, which can reach up to 6.5 feet (2 meters) across, harpies fly through their forest home with great agility. |
| The wings are short and broad, which helps the eagle climb almost vertically and attack from below as well as from above | Its short, broad wings help the harpy fly almost straight up, too, so it can attack prey from below as well as above. |
| The nest is a frame of large sticks lined with softer greens, seedpods, and animal fur, and it can measure about 1.5 meters (5 feet) across | Harpies use large sticks to create the nest's huge frame and line it with softer greens, seedpods, and animal fur to make it warm and comfortable. A harpy nest measures about 4 feet (1.2 meters) thick and 5 feet (1.5 meters) across |
| a harpy eagle perches silently for up to 23 hours before snatching monkeys and sloths from the branches | The bird perches silently for hours—up to 23!—in a tree, patiently waiting to catch unsuspecting prey (note: task #799, vibe.reason) |

## Harpia harpyja. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

https://genomics.senescence.info/species/entry.php?species=Harpia_harpyja

| The page says | The source says |
| :--- | :--- |
| the maximum AnAge lists is 16.8 years, for a captive bird recorded in a 1938 study of bird longevity | Maximum longevity 16.8 years (captivity) Source ref. 575 ... [ 0575 ] Flower (1938), Furter notes on the duration of life in animals. IV. Birds |

## Miranda et al. (2019). Species distribution modeling reveals strongholds and potential reintroduction areas for the world's largest eagle. PLOS ONE.

https://doi.org/10.1371/journal.pone.0216323

| The page says | The source says |
| :--- | :--- |
| A 2019 study on the species put the average at 6.6 kilograms and called it "the largest extant raptor on Earth" | Averaging 6.6 kg, the Harpy Eagle is the largest extant raptor on Earth |
| beaten in size only by the extinct Haast eagle of New Zealand | surpassed in size by only the extinct, island-living Haast Eagle (Harpagornis moorei ...), which humans wiped out from New Zealand's South Island |
| a 2019 study found that Amazonian forests held 93% of the species' current distribution | Amazonian forests currently represent 93% of the current distribution of the species |

## Miranda et al. (2021). Tropical deforestation induces thresholds of reproductive viability and habitat suitability in Earth's largest eagles. Scientific Reports.

https://doi.org/10.1038/s41598-021-92372-z

| The page says | The source says |
| :--- | :--- |
| A 2021 study of 16 active nests in Amazonian landscapes that had lost 0 to 85% of their forest | We monitored 16 active harpy eagle nests embedded within landscapes that had experienced 0 to 85% of forest loss |
| harpy eagles could not switch to open-habitat prey in deforested areas, that feeding rates fell with forest loss, and that landscapes deforested by more than 70% supported no nests | Harpy eagles could not switch to open-habitat prey in deforested habitats ... Feeding rates decreased with forest loss ... Because landscapes deforested by > 70% supported no nests |
| Three fledged eaglets in that study died of starvation in landscapes that had lost 50 to 70% of their forest | three fledged individuals dying of starvation in landscapes that succumbed to 50–70% deforestation |

## Gil-da-Costa et al. (2003). Rapid acquisition of an alarm response by a neotropical primate to a newly introduced avian predator. Proceedings of the Royal Society of London. Series B: Biological Sciences.

https://doi.org/10.1098/rspb.2002.2281

| The page says | The source says |
| :--- | :--- |
| including howler monkeys | mantled howler monkeys (Alouatta palliata), one of their primary prey |
| Mantled howler monkeys are "one of their primary prey" | mantled howler monkeys (Alouatta palliata), one of their primary prey |
| after harpy eagles were reintroduced to Barro Colorado Island in Panama, where they had been extinct for 50 to 100 years, researchers played eagle calls to the island's howlers | we took advantage of the recent reintroduction of radio-tagged harpy eagles (Harpia harpyja) to Barro Colorado Island (BCI), Panama ... we broadcast harpy eagle calls to howlers on BCI ... Although harpies have been extinct from this area for 50-100 years (note: Design: the researchers used an existing reintroduction and broadcast recorded calls; they did not reintroduce the eagles themselves.) |
| The monkeys quickly picked up an anti-predator response to those calls, ignored other birds' calls | BCI howlers rapidly acquired an adaptive anti-predator response to harpy calls, while showing no response to other avian vocalizations |
| kept it up several months after the eagles were removed | howlers maintained this response several months after the removal of the eagles |

## Harpia harpyja. The IUCN Red List of Threatened Species 2021: e.T22695998A197957213.

https://doi.org/10.2305/iucn.uk.2021-3.rlts.t22695998a197957213.en

| The page says | The source says |
| :--- | :--- |
| The IUCN lists the species as Vulnerable | IUCN Red List category: Vulnerable (VU). |