Harris’s Hawk Facts

Harris’s Hawk Profile

[In Sam Neil’s voice]

Okay. Try to imagine yourself in the Arizona desert. You get your first look at this “three-foot turkey” as you come out from behind a Saguaro.

He moves like a velociraptor, lightly, bobbing his head — and you keep still ’cause you think that maybe his visual acuity is based on movement, like a coyote, he’ll lose you if you don’t move — but no, not Harris’s hawk. 

You stare at him, and he just stares right back. And that’s when the attack comes… not from the front, but from the side, from the other two raptors you didn’t even know were there. Because Harris’s Hawk’s a pack hunter.

He used coordinated attack patterns, and he is out in force today. And he pierces your chest with this three-inch, razor-sharp talons. Like meat hooks, on the end of their feet.

Harris’s Hawk Facts Overview

The Harris’s Hawk maintains a velociraptor spirit by being a formidable, intelligent predator that has learned to work in packs both for hunting and breeding.

These large and heavy raptors hunt together more than any other bird of prey, and the intelligence this necessitates translates into a clever and trainable bird, popular in falconry. 

Interesting Harris’s Hawk Facts

1. They’re highly social 

Harris’s hawk society is dominated by females. Their setup is a linear one, with the top bird sitting above a series of increasingly subordinate individuals beneath her.

The leader is always an adult female, but there are a few varying dynamics commonly found.

Sometimes, it’s a simple pair, with the male supporting the female. Sometimes, a pair like this will have a male helper who’s subordinate to the two (this is the most common setup) and sometimes there’s a second female, who is subordinate to the matriarch, but dominant over the male. 

In this last dynamic, which in one study was found to make up around a third of cases, the male will often have a go with the second female and will be embarrassingly rejected. 

Interestingly, the low-ranking male helpers were usually the offspring of the pair, but the second-ranking females were unrelated. 

Maintaining dominance over the males isn’t a difficult task in Harris’s hawks, as females tend to be enormous. ¹

2. They’re very sexually dimorphic

The average weight of adult males is around 700g, with a large male possibly pushing close to 900g.

But the females of this species are more than a third heavier, with an average weight of around a kilo, and an upper boundary of more than 1.6kg, meaning that they can be more than twice the size of males in some instances. 

In birds, sexual dimorphism, or the differences in the physical characteristics between sexes of conspecifics, is often expressed in the colour differences between the sexes. In raptors, though, this doesn’t happen as often, and it’s most commonly a matter of size.

Quite patronisingly, this is often called “reverse sexual dimorphism”, because as mammals, we consider it more familiar to have larger males than females.

But in reality, in most animal species where one sex is bigger than the other, it’s the females. So really, we’re the backward ones. 

Regardless of the politics of it all, these dominance hierarchies serve a strategic purpose, and one of those purposes is to become epic predators or more or less anything. 

3. They’ll eat a lot of things

When you want to know what something eats, there are two ways to go about it. You can follow it around with binoculars and a notepad, chasing after it 24/h a day and documenting its activities as best you can, or you can go through its poo. 

Behaviourists are an inherently scatological lot already, so the choice is a no-brainer. And this is how they discovered that the Harris’s hawk is an exceptionally generalist predator. 

From sifting through the cloaca cake of various hawks, 68 prey species were identified. This included nine bird species, two orders of insects, four rodent species, and some exceptionally large lagomorphs, including the impressive European hare, which made up 60% of their diet. 

This is an animal that can weigh up to 4kg and run 70 km/h, both metrics that outpace the hawk, but the raptors overcome this by working together. ²

4. They hunt in packs

While larger females and matriarchal societies aren’t all that uncommon among raptors, the level to which these birds work together when hunting definitely is. 

These clever predators team up to coordinate hunts, allowing them to bring down and share bigger prey than they would be able to manage alone. 

Hunting parties can be made up of up to six individuals and have been shown to increase the chances of success on any given hunt.

In some places, the species hunts like this all year, in others, it’s a more seasonal event, showing some form of plasticity in the behaviour, likely based on the availability of resources. 

They will form scouting parties, ambushes, and work to flush prey towards a waiting capture team and will even chase prey on foot. 

But it’s not only hunting that they team up for, they also help each other with the family chores. ³

5. They breed in packs too

Breeding groups of Harris’s hawks studied in Arizona numbered between 2 and 7. When more than two birds are involved in the breeding strategies, this is known as cooperative breeding and involves non-parent birds helping to take care of the nests of their community members. 

This breeding strategy is not common but is known to occur in around 300 species of bird (or 9% depending on which estimate you follow), though in raptors it’s closer to 6% of species, making it rarer than average. 

There’s some evidence to suggest a correlation between cooperative breeding in birds and more complex vocalisations.

And more complex vocalisations are associated with higher cognitive function. While there isn’t much data on the vocal complexity of Harris’s hawks, they do tick the box for smarts. ⁴

6. They’re intelligent 

Since the ‘80s, this species has gained traction among the falconry community, and in the Western world, they’re now one of the most popular hawks used. 

Being highly social necessitates intelligence, and intelligent birds like this are easier to train.

Harris’s hawks are said by some to be the most intelligent hawk of them all and are commonly used to remove vermin like pigeons, or simply prevent them from approaching simply by being present. 

Harris’s Hawk Fact-File Summary

Scientific Classification

1. R. WILLIAM Mannan(1991), “Dominance Hierarchies and Helper Contributions in Harris’ Hawks”, Research Gate.
2. Ricardo A. R. Figueroa (2006), “PREY OF THE HARRIS’S HAWK (PARABUTEO UNICINCTUS) IN A SUBURBAN AREA OF SOUTHERN CHILE”, Bio One Digital Library.
3. Jennifer O. Coulson (2013), “Reexamining Cooperative Hunting in Harris’s Hawk (Parabuteo unicinctus): Large Prey or Challenging Habitats?”, Oxford Academic.
4. James William (1957), “The cooperative breeding system of the Harris’ Hawk in Arizona”, The University of Arizona.