Circus cinereus
Silhouette: Shyamal · PhyloPic
In 3 days ~20% in a week ~40%
The cinereous harrier (Circus cinereus) is a South American bird of prey of the harrier family. Its breeding range extends from the Tierra del Fuego through Argentina and Chile to Bolivia, Paraguay, Peru and southern Brazil; and across the Andes north to Colombia. The bird's population is declining but due to its large range is not considered vulnerable. The term cinereous, deriving from the Latin word for ashy, describes its colouration.
The male's plumage is dark grey above with black wingtips and a white rump. The underparts are pale grey, with a rufous streaked belly. The female's plumage is brown above, with a white rump, and cream coloured underneath, with a streaked belly similar to the males. The female is larger than the male with an average size of 46 cm (18 in) compared to the male's 40 cm (16 in). The wingspan is 90–115 cm (35–45 in). Since the 44.5 cm (17.5 in) tail comprises about 56% of this raptor's total length, this species ties with the long-tailed hawk as the raptor with the longest tail relative to its body size.
This bird can be found in different open habitats, ranging from lowland marshes to the Andean Altiplano at... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Torres del Paine National Park | 🇨🇱 Chile | |
| 2 | Península Valdés | 🇦🇷 Argentina | |
| 3 | Iberá National Park | 🇦🇷 Argentina | |
| 4 | Nahuel Huapi National Park | 🇦🇷 Argentina | |
| 5 | Tierra del Fuego National Park | 🇦🇷 Argentina |
With luck
About 10% of wildlife watchers report a Cinereous Harrier sighting in Nahuel Huapi National Park on a given day, based on 65 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 63rd most-seen of the 111 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
September
In that month about 20% of wildlife watchers report a Cinereous Harrier in Nahuel Huapi National Park on a given day, against under 5% in January–June and August, the lowest months.
Between 4 and 7 pm
Across all the parks we cover, that three-hour window holds the most Cinereous Harrier sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 5
Of the 5 parks where we can rate Cinereous Harrier sightings, Nahuel Huapi National Park ranks 4th at about 10%. The best odds are in Torres del Paine National Park (Chile, about 40%), Península Valdés (Argentina, about 10%) and Iberá National Park (Argentina, about 10%).
Same family: Accipitridae
The closest relatives of the Cinereous Harrier that you can see in Nahuel Huapi National Park (family Accipitridae, Hawks, Eagles, and Kites) are Black-chested Buzzard-Eagle (about 10%) and Variable Hawk (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Cinereous Harrier is recorded against all the birds logged in Nahuel Huapi National Park (65 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
