Stercorarius parasiticus
Silhouette: Liam Quinn (photo) and Albertonykus (silhouette) · PhyloPic
In 3 days <5%
The parasitic jaeger or arctic skua (Stercorarius parasiticus), also known as the parasitic skua or arctic jaeger, is a seabird in the skua family Stercorariidae. It is a migratory species breeding in Northern Fennoscandia, Scotland, Iceland, Greenland, Northern Canada, Alaska, and Siberia and wintering across the southern hemisphere. Kleptoparasitism is a major source of food for this species during migration and winter, and is where the name is derived from.
The parasitic jaeger was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae under the binomial name Larus parasiticus. Linnaeus specified the type locality as "within the Tropic of Cancer of Europe, America and Asia" but this is now restricted to the Swedish coastline. The parasitic jaeger is now placed with the six other skuas in the genus Stercorarius that was introduced in 1760 by the French zoologist Mathurin Jacques Brisson. The species is considered to be monotypic: no subspecies are recognised. The genus name Stercorarius is Latin and means "of dung"; the food disgorged by other birds when pursued by skuas was once thought to be excrement. The specific... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Svalbard | 🇳🇴 Norway | |
| 2 | Vatnajokull National Park | 🇮🇸 Iceland | |
| 3 | Bastimentos Island National Marine Park | 🇵🇦 Panama | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany | |
| 5 | Channel Islands National Park | 🇺🇸 United States | |
| 6 | El Vizcaíno Biosphere Reserve | 🇲🇽 Mexico | |
| 7 | Kenai Fjords National Park | 🇺🇸 United States | |
| 8 | La Amistad International Park (Panama) | 🇵🇦 Panama | |
| 9 | Great Bear Rainforest | 🇨🇦 Canada | |
| 10 | Wilsons Promontory National Park | 🇦🇺 Australia | |
| 11 | Nahuel Huapi National Park | 🇦🇷 Argentina | |
| 12 | Table Mountain National Park | 🇿🇦 South Africa | |
| 13 | Cabo Blanco Absolute Nature Reserve | 🇨🇷 Costa Rica | |
| 14 | Celestún Biosphere Reserve | 🇲🇽 Mexico | |
| 15 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 16 | Pacific Rim National Park Reserve | 🇨🇦 Canada | |
| 17 | Acadia National Park | 🇺🇸 United States | |
| 18 | Manuel Antonio National Park | 🇨🇷 Costa Rica | |
| 19 | Olympic National Park | 🇺🇸 United States | |
| 20 | Redwood National Park | 🇺🇸 United States | |
| 21 | Galápagos Islands | 🇪🇨 Ecuador | |
| 22 | Point Pelee National Park | 🇨🇦 Canada |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dakar | 🇸🇳 Senegal | |
| 2 | Tel Aviv | 🇮🇱 Israel | |
| 3 | Busan | 🇰🇷 South Korea | |
| 4 | Kuwait City | 🇰🇼 Kuwait | |
| 5 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 6 | Kozhikode | 🇮🇳 India | |
| 7 | San Diego | 🇺🇸 United States | |
| 8 | Dublin | 🇮🇪 Ireland | |
| 9 | San Francisco | 🇺🇸 United States | |
| 10 | Melbourne | 🇦🇺 Australia |
Rare
Under 5% of wildlife watchers report a Parasitic Jaeger sighting in Porto on a given day, based on 17 verified sightings from GBIF citizen-science data. It is the 154th most-seen of the 175 birds we can rate there. Over three days the chance rises to under 5%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Parasitic Jaeger in Porto on a given day, so our monthly data shows no clear season.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Parasitic Jaeger sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
15th of 26
Of the 26 cities where we can rate Parasitic Jaeger sightings, Porto ranks 15th at under 5%. The best odds are in Dakar (Senegal, about 30%), Tel Aviv (Israel, under 5%) and Busan (South Korea, under 5%).
Same order: Charadriiformes
The closest relatives of the Parasitic Jaeger that you can see in Porto (order Charadriiformes, Shorebirds and Allies) are Yellow-legged Gull (about 80%), Lesser Black-backed Gull (about 40%) and Black-headed Gull (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Parasitic Jaeger is recorded against all the birds logged in Porto (17 verified sightings), 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.
