Montagu’s Harrier: The Ultimate Guide

The Montagu’s harrier (scientifically known as Circus pygargus) is a migratory bird of prey that spends its life moving between the United Kingdom, Europe, and Africa. The unique name of this species was given to commemorate George Montagu, a British naturalist who specialized in birds. 

Despite its unique plumage, the Montagu’s harrier is often mistaken for other species, such as the hen harrier and pallid harrier.

As a result of this, it’s important that we understand the distinguishing features between these species to better understand the Montagu’s harrier. 

Here is the ultimate guide to the Montagu’s harrier!


The Montagu’s harrier is considered a small bird of prey despite its impressive wingspan. With a body the length of 17-19” (plus a 6-7” tail) and a wingspan of 38-45”, this species is deceptively small until it takes flight.

These large wings are essential to provide a buoyant flight for the long migratory journeys. 

The appearance of a Montagu’s harrier is an interesting one, because this species exhibits sexual dimorphism (where there are clear physical differences between the male and female).

Male Montagu’s harriers have a predominantly gray plumage with black wing tips and rusty streaks on their bellies. Female Montagu’s harriers are mostly dark brown on the upper parts, with a pale yellowish belly and spotted wing coverts.

More information on the sexual dimorphism of this species can be found in the next section of this guide!

Due to the physical differences between the male and female Montagu’s harrier, it makes sense why the species is often mistaken for other birds of prey. 

Male vs Female

Unlike many birds of prey species, the Montagu’s harrier is a sexual dimorphic species, which means that it’s easy to tell the difference between a male and female. In general, the females are larger than the males (with the females weighing 345 g and the males weighing 265 g), which is most likely due to the eggs they have to carry and produce. 

The easiest way to distinguish between the male and female is its plumage. The males are significantly more gray than the females, with black tips of their wings making for a pigeon-like plumage. 

The females, however, are mostly varying shades of dark to light brown.

Their underparts are mostly yellow-brown with vertical brown stripes and slightly spotted wing coverts. It is argued that the female looks distinctly more like a bird of prey than the male, as the female looks more like a hawk or buzzard. 

Before the plumage is distinguishable, the best way to tell juveniles apart is by the color of their irises. Male juveniles have yellow irises, while females have dark brown irises. 

Are They Aggressive?

The Montagu’s harrier isn’t an overtly aggressive bird of prey, but research has suggested that they do possess aggressive behavior when they are nesting. This means that if a human were to approach the nest of a Montagu’s harrier, the bird wouldn’t hesitate to attack.

This also goes for other birds of prey. 

What Adaptations Do They Have?

The Montagu’s harrier is a highly adaptable bird of prey due to its migratory status that allows it to adapt to different environments. While they spend most of their time in wetlands and marshes, they are known to nest up to 1,500 meters.

They can also adapt to shrublands and agricultural farmland. 

Breeding / Reproduction Habits

It’s not clear whether the Montagu’s harrier is a monogamous bird of prey or not, because they are either seen alone or with several other birds of the same species.

Loose colonies are often made during the breeding season, often made of 30 nests several meters apart, which is mostly for safety in numbers. The more birds in the same area, the more they can fight predators. 

The courting ritual consists of both the male and female birds performing aerial displays and calls. The male’s displays are often more vibrant than the female’s, who will then submit if the male is successful.

The female will build a nest in tall vegetation made of grass, before she then lays between 3-5 eggs.

The incubation period is likely to be shared by both parents for 27-40 days, but the females probably do all the work. After 28-42 days, the young will leave the nest. 

Interestingly, while the female birds are fairly monogamous and will only mate with the same partner, the males are more polygamous and will have multiple partners. 

Their Calls / Sounds

The call of a Montagu’s harrier is a high-pitched, soft squeak. These aren’t the noisiest of birds, and are only vocal during the courting rituals or if they see a potential predator. 

What Do They Eat? (Diet)

The Montagu’s harrier’s diet mostly consists of small rodents, small mammals, small reptiles, small birds, eggs, and large insects. The species itself is fairly small for a bird of prey, so they can only eat so much! 

However, as they have a wide distribution across Europe and their migratory journeys, they will eat just about anything in the immediate environment.

For example, in Northern Europe they will feast on rabbits and squirrels, whereas they will eat snakes and voles in Southern Europe. When they migrate to Africa, they are likely to eat nutritious termites and other insects. 

Their method of catching prey is unique, wherein the male will often fly above the female who will then catch the prey that he drops. She will then take this back to her hatchlings. 

Where Do They Live? (Habitat)

The Montagu’s harrier is most commonly found in the UK and Europe. The species is mostly limited to southern England and parts of Europe, though it is not present in Norway. Some of these birds are known to nest in Morocco. These birds are most commonly found in France, Spain, Belarus, Poland, and Russia. Then, they migrate to Africa. 

This is a lowland species that spends most of its time in wetlands and marshes, though it can easily adapt to different habitats such as heaths, moors, shrublands, and agricultural farmland.

This species prefers open land with tall vegetation to hide their nests, with tall posts such as fence posts or small trees to overlook for predators. 

What Are Their Nesting Habits?

The most favorable place for nesting are wet areas, such as plains, banks, rivers, lakes, and the sea. However, they can also adapt to nest in moors and shrublands with sufficient vegetation to hide their nests.

These nests are made out of the seasonal grass, which means they are usually destroyed once the birds migrate. It’s common, however, for the females to return to their previous nesting spot for the next breeding season. 

How Long Do They Live? (Lifespan)

The maximum lifespan of the Montagu’s harrier in the wild is estimated to be 16 years, though the average lifespan is suggested to be far shorter than this. 

What Predators Do They Have?

When it comes to animals, the Montagu’s harrier doesn’t have many predators. The juveniles might be considered prey by other birds of prey, but even larger birds of prey might consider the adults prey. 

Unfortunately, the main predator to the Montagu’s harrier is humanity. Habitat loss for the sake of agricultural farmlands have destroyed the homes of most harriers, particularly in the UK.

While these birds can adapt to agricultural farmlands, that won’t stop farmers from shooting the birds should they threaten their livestock. 

What Are Their Feathers Like?

The feathers of a male Montagu’s harrier are mostly gray, except for the wing feathers that have a long black tip. The feathers of a female Montagu’s harrier are more colorful, as most of their body is made up of brown and yellow-brown feathers.

They don’t have the fluffiest of plumage, which is mostly because they migrate to warmer countries in the winter. 

What Does Their Poop Look Like?

Unfortunately, there is little information about the poop of a Montagu’s harrier. It is assumed that their poop is brown with the occasional black, yellow, or white patches. 

Do They Migrate?

The Montagu’s harrier is a migratory bird which spends the winter months in sub-Saharan Africa. Those from the eastern part of Eurasia are said to migrate to the warmth of India during this time.

The migration time usually starts in mid-August, with all the birds successfully migrating in October and arriving back home between April and May. Some birds are said to have migrated as far as South Africa!

Conservation Status

The conservation status of the Montagu’s harrier is Least Concern. This is due to their wide habitat distribution. However, in Western Europe, most harriers nest in agricultural farmland, which usually results in them being shot by farmers.

In the UK especially, they are considered a rare species. 

Fun Facts

  • When the chicks have hatched, the female won’t allow the male near the nest. Instead, the male will drop the food from above the nest. 
  • The Montagu’s harrier is a graceful flier due to their large wingspan that provides buoyancy and elegance. 
  • The Montagu’s harrier is named after the British naturalist George Montagu, who paved the way for defining bird species with his 1802 book, the Ornithological Dictionary.