Montagu's Harrier (Circus pygargus)

Identification

Identifying Montagu's Harrier requires careful observation, particularly to distinguish females and juveniles from other harrier species.

• Adult Male Plumage: Adult males are predominantly ash-grey on the upper body, head, and chest. Their wingtips (primary flight feathers) are black. A distinctive feature is a slender black bar crossing the secondary flight feathers on the upper side of each wing. The underparts are whitish with fine rufous streaks.
• Adult Female Plumage: Females are strikingly different from males. Their upperparts are dark brown with rufous edges on the head and nape. A pale patch is visible below the eye. They have a white rump, and their underparts are rufous to cream, streaked with dark brown.
• Juvenile: Young Montagu's Harriers have darker and more rufous plumage than females, with almost uniform, lightly streaked rufous-yellowish underparts. The iris is dark.
• Silhouette and Flight: All individuals have a slender and elegant silhouette, with long, narrow wings and a long tail. They fly with remarkable agility, often holding their wings in a "V" shape.
• Sexual Dimorphism: Sexual dimorphism is marked in this species, with females generally being larger and darker than males.

Scientific Dimensions and Records (Montagu's Harrier)

These figures confirm Montagu's Harrier as a moderately sized raptor with a notable lifespan in its natural environment.

Song and Calls

Montagu's Harrier is generally silent outside the breeding season. However, during courtship displays and when alarmed or disturbed, it emits various vocalizations.

Its calls can include:

• A "buzzard-like" call but shorter, sharp, and harsh.
• Short, repeated calls like "kiek kiek kiek" or "kie kie kie" when uneasy, becoming faster and more emphatic if alarm increases.
• During courtship flights, rapid and high-pitched "kekeke" or "kaillek-kaillek" sounds.
• The female may emit shrill "psiii" calls when exchanging prey with the male in flight.
• Chicks beg for food with insistent, high-pitched "pjiiiiiiiiiiiiiuuh" calls.

Habitat and Distribution of Montagu's Harrier

Montagu's Harrier is a raptor of open habitats, preferring grassy areas, meadows, heather moorlands, fallow land, marshes, peat bogs, and cultivated areas. It has particularly adapted to large cereal crops (wheat, barley), where it establishes almost all of its nests in many parts of its range, including France. It is typically found in plains and hills, but nesting can be observed up to 1300 meters (4265 ft) altitude.

Its breeding range extends from Western Europe (including Spain, France, Great Britain) eastward through the Russian and Kazakh steppes, as well as northern Africa and the Middle East. It is a strict migrant, wintering in sub-Saharan Africa (from the Sahelian zone to the Cape Province) and the Indian subcontinent. Migration routes often include the Strait of Gibraltar and Cap Bon in Tunisia.

Distribution Map

Diet

Montagu's Harrier is an opportunistic and carnivorous predator. Its diet primarily consists of small rodents, particularly the Common Vole, whose population surges often lead to better breeding years.

It supplements its diet with a wide variety of prey caught on the ground, including:

• Small birds (passerines, larks, buntings, pipits) and their chicks or eggs.
• Reptiles, such as lizards and small snakes.
• Amphibians, such as frogs.
• Large insects, especially orthopterans (grasshoppers, locusts, crickets) and beetles.

It hunts by flying slowly and low over its hunting grounds, quartering the area in several straight lines and flying into the wind. When prey is detected, it drops sharply to seize it with its talons.

Reproduction

The breeding season for Montagu's Harrier generally occurs between April and August, with egg-laying from mid-May to mid-June in most European regions, and as early as late April in Morocco. Birds usually breed at two or three years of age.

• Nest: The nest is built primarily by the female, directly on the ground, within dense and tall vegetation. It is often located in cereal fields, but also in heathlands, meadows, or marshes. It's a shallow platform made of grasses and twigs. The species may nest in loose colonies in areas rich in prey.
• Eggs: The female typically lays 3 to 5 eggs (sometimes 1 to 7), which are pale blue or green, speckled with brown. Incubation often begins with the laying of the first egg and lasts an average of 28 to 29 days.
• Raising the Young: Both parents participate in raising the young. The male feeds the female during incubation, and then both parents bring food to the chicks. The male is known to drop food from above the nest for the female or young. Young leave the nest and take their first flight after 30 to 40 days and become independent 2 to 3 weeks later. A pair can have up to one brood per year, but breeding success is strongly linked to vole abundance.
• Courtship Display: Montagu's Harriers perform elaborate and spectacular courtship flights, involving aerial acrobatics, high-altitude circles, dives, and mid-air food exchanges.

Conservation Status

Montagu's Harrier is classified as "Least Concern" (LC) by the IUCN (International Union for Conservation of Nature) globally. However, this classification masks a more concerning reality in some regions.

In mainland France, the species is considered "Near Threatened" on the IUCN Red List and is undergoing a significant decline across Europe. Montagu's Harrier is protected in France and listed in Annex I of the European Birds Directive, granting it national, European, and international protection status.

The main threats to the species are related to human activities:

• Nest Destruction: The destruction of broods by agricultural machinery during early cereal harvests is the most significant threat, as nests are on the ground and fledging often occurs after harvest dates.
• Decline in Food Resources: The scarcity of prey, particularly voles, due to agricultural intensification and the loss of grasslands, affects breeding success.
• Habitat Degradation: The loss of natural nesting habitats (heathlands, marshes, fallow land) due to conversion to crops or urbanization.
• Toxic Products: The use of pesticides and rodenticides in agriculture also poses a threat.

Conservation programs involving organizations like the RSPB (Royal Society for the Protection of Birds) in the UK, the LPO (Ligue pour la Protection des Oiseaux) in France, local associations, and farmers are implemented to locate and protect nests during harvests, especially in key areas.

Frequently Asked Questions (FAQ)

References

1. Wikipedia - Montagu's Harrier