Northern Harrier

How to find it

Choose wide open grassland, marshes, rice fields or farmland, and scan low over the vegetation rather than high in the sky. Watch for the slow, side-to-side flight and the V-shaped wings, and when the bird turns away, look for the white rump. Rice fields and wetlands in Guanacaste can be excellent during migration. Along the Sarapiqui road, birders scanning for migrating raptors such as Broad-winged and Swainson's Hawks may also pick up a harrier. Tour leaders call it scarce in winter, so give it time.

How to recognise it

Look for a slim hawk with long wings and a long, thin tail. It glides with its wings held in a shallow V.

A white patch at the base of the tail shows in every plumage. It is often the best mark on a bird flying away.

The face is owl-like, with a flat facial disc that helps it hear mice and voles hidden under vegetation.

The male is pale gray above and white below with cinnamon spots. The female is dark brown above and streaked buff and brown below. Immatures resemble females but are more rufous below.

What it sounds like

Recording: River Ahlquist, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

The harrier hunts on the wing, flying low over the ground in a slow, side-to-side search. It relies on hearing as well as sight, and it takes mostly small and medium mammals and birds.

It is usually noticed in flight, by that low quartering and the V-shaped wings. In winter, individuals roost together on the ground.

In Costa Rica it also passes through on migration, mostly through the Caribbean lowlands.

Where it lives

Across its range the harrier uses open country with low, dense vegetation, such as marshes, wet meadows, grasslands and pastures. It generally avoids heavily forested areas.

In Costa Rica it is most numerous on the Pacific slope, as it is in Nicaragua and Panama. It also turns up in the northern Caribbean lowlands and over the wide wetlands near Caño Negro in the far north.

When to see it

Birds arrive in early October and leave in early May. One tour source says it is usually found only in western Costa Rica until early April.

Similar birds

In Costa Rica a harrier is told from other hawks by its long wings, long thin tail, distinct owl-like face disc and a white rump patch in every plumage. It was until recently treated as the same species as the Hen Harrier of Eurasia, and the two differ in genetics and plumage.

Names and lore in Costa Rica

The official Spanish name is Aguilucho Norteño, the name Costa Ricans commonly use. Other Spanish names include Gavilán Rastrero, Gavilán de Ciénaga and Aguilucho de Hudson, and some of these are used across Latin America, not only in Costa Rica.

Status and conservation

The official Costa Rica list marks the Northern Harrier as M, a migrant, and the IUCN lists it as Least Concern although its population is decreasing.

Photography tips

Look for open, windy fields where the bird flies low and fast, and keep your eye on the white rump as it turns away. Scanning wetlands and rice fields in the early part of the season, with patience, gives the best chance.