Circus aeruginosus
Silhouette: Mathieu Pélissié · PhyloPic
In 3 days ~10% in a week ~20%
The western marsh harrier (Circus aeruginosus) is a large harrier, a bird of prey from temperate and subtropical western Eurasia and adjacent Africa. It is also known as the Eurasian marsh harrier. Formerly, a number of relatives were included in C. aeruginosus, which was then known as "marsh harrier". The related taxa are now generally considered to be separate species: the eastern marsh harrier (C. spilonotus), the Papuan harrier (C. spilothorax) of eastern Asia and the Wallacea, the swamp harrier (C. approximans) of Australasia and the Madagascar marsh harrier (C. maillardi) of the western Indian Ocean islands.
The western marsh harrier was scientifically described by Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Falco aeruginosus. Linnaeus specified the locality as Europe but restricted this to Sweden in 1761. The western marsh harrier is now placed in the genus Circus that was introduced by Bernard Germain de Lacépède... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Vasai-Virar | 🇮🇳 India | |
| 2 | Rabat | 🇲🇦 Morocco | |
| 3 | Luxor | 🇪🇬 Egypt | |
| 4 | Cairo | 🇪🇬 Egypt | |
| 5 | Kalyan-Dombivli | 🇮🇳 India | |
| 6 | Indore | 🇮🇳 India | |
| 7 | Tunis | 🇹🇳 Tunisia | |
| 8 | Abu Dhabi | 🇦🇪 United Arab Emirates | |
| 9 | Surat | 🇮🇳 India | |
| 10 | Helsinki | 🇫🇮 Finland |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | ZooParc de Beauval | 🇫🇷 France | |
| 2 | Parc du Belvédère | 🇹🇳 Tunisia | |
| 3 | Tiergarten Halberstadt | 🇩🇪 Germany | |
| 4 | Hortobágyi Madárpark | 🇭🇺 Hungary | |
| 5 | Дендропарк ім. Бенедикта Дибовського | 🇺🇦 Ukraine | |
| 6 | akwarium warszawskiego ZOO | 🇵🇱 Poland | |
| 7 | hipopotamiarnia i akwarium morskie warszawskiego ZOO | 🇵🇱 Poland |
Rare
Under 5% of wildlife watchers report a Western Marsh-Harrier sighting in Nairobi National Park on a given day, based on 48 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 268th most-seen of the 371 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
January–March and November
In those months about 10% of wildlife watchers report a Western Marsh-Harrier in Nairobi National Park on a given day, against under 5% in April–October and December, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Western Marsh-Harrier sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
25th of 40
Of the 40 parks where we can rate Western Marsh-Harrier sightings, Nairobi National Park ranks 25th at under 5%. The best odds are in Hortobágy National Park (Hungary, about 80%), Kiskunság National Park (Hungary, about 70%) and Fertő-Hanság National Park (Hungary, about 70%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the Western Marsh-Harrier is recorded against all the birds logged in Nairobi National Park (48 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.
