Montagu's harrier

 

Montagu’s harrier (Circus pygargus) is very similar in appearance to the hen harrier, and was only recognised as a separate species in 1802 by the Devon naturalist George Montagu, hence the name. The hen harrier is far more common in the United Kingdom, with Montagu’s Harrier being one of Britain’s rarest breeding birds, limited to a few pairs in southern England.

Adult male Montagu’s harriers, which are more slightly built than hen harriers, are up to 16 inches (40 cm) in length. They have black wing-bars and brown streaks on the whitish underwings and flanks. The upperparts are grey and underparts white. Females are brown above and white streaked with brown below, with a narrow white rump patch.

The flight is buoyant with the wings raised in a shallow V.

Montagu’s harriers often perch on posts that overlook grassland as they scan the ground for prey that includes insects and small mammals.

The Montagu’s harrier winters in Mediterranean regions and tropical Africa and those that nest in Great Britain arrive in April, settling down in pairs by the end of May or early June. The nest will be on the ground among vegetation in any kind of open country, including farmland and sand dunes.

The eggs are laid at intervals of up to three days with incubation beginning as soon as the first egg is laid. The young hatch at the same intervals after four weeks.

The female greets the male as he brings food for her and the hatched chicks. The prey is passed from foot to foot in midair or, if dropped by the male, will be caught by the female before it hits the ground. She will share the hunting after around three weeks. The chicks fledge at around five weeks and all the birds will fly south in September.

© John Welford