Parasitic Jaeger

Stercorarius parasiticus

Order: Charadriiformes
Family: Stercorariidae
Presence in the Strait: Seasonal
Abundance: common
Protection in Spain: Special protection (List)
In Spanish: Págalo parásito

Photograph: Fyn Kynd, CC BY-SA, vía iNaturalist

Length: 46–67 cm
Wingspan: 97 cm
Weight: 450 g

Presence in the Strait

Common pelagic winter visitor.

Identification

Smaller and slighter than the Pomarine Skua, with pointed tail projections. Rapid and agile flight. Usually harass terns and gulls in order to steal their catches. Lighter and darker phases exist. Juveniles are very similar to those of a Pomarine Skua but smaller.

Movements

Peaks in April and September.

Ring recoveries

United Kingdom (3).

Bioestrecho editorial text. Last revised: 8 September 2026.

Photographs from iNaturalist observations with the licence checked file by file. Those marked “Strait” were taken within the area; place and date are those of each observation.

Calendar in the Strait

21 %

Peak in October. Observations under CC0 or CC BY licences. The distribution also reflects observation effort.

Where it is seen

Open records from the atlas database, in cells of about 3.6 km. Opacity follows the square root of the count, and also reflects where people observe most.

See on the map

First open record: 6 October 1980
Latest record: 7 December 2024

The oldest and the most recent open observation in the extended area. A recent first observation does not mean the species is new: it means nobody had published it openly before.

Conservation

The catalogues, Andalusian and Spanish, are what binds; the Red Book assesses the Spanish population with IUCN criteria, and the global Red List is the context.

LCNTVUENCR

Andalusian Catalogue: Special protection (List)
Spanish Catalogue: Special protection (List)
Red Book of the Birds of Spain 2021: NE · Not evaluated · wintering or migrating
Global Red List (IUCN): LC · Least concern

Andalusian Catalogue: Junta de Andalucía, list of 24 April 2025. Spanish Catalogue: MITECO, table of 30 June 2025. Red Book: SEO/BirdLife, 2021 (Annex I). IUCN: via GBIF, 6 September 2026. Red Book and IUCN categories are assessments; catalogue categories are legal obligations.

Phenology compared

Monthly distribution in proportion, by decade. It shows whether the passage is getting earlier or later.

2000–2009

2010–2026

Proportions, not totals: observation effort grew faster than any population.

Where they come from

3 birds ringed in other countries and recovered in the area.

United Kingdom3

See the journey on the map

Same genus in the Strait

Great Skua53–66 cm · Seasonal · overlapping size
Pomarine Skua65–78 cm · Migrant · overlapping size

Species of the same genus that also occur here, ordered by how close they are in size. Being relatives does not mean they are confused in the field, but that is where the doubts start: compare size and season.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Stercorariidae
GBIF taxon key: 2481621

Sources

Distribution and calendar: Bioestrecho's own database, ingested from GBIF and OBIS
Photograph: Fyn Kynd, CC BY-SA, vía iNaturalist
Taxonomy: GBIF backbone, pending WoRMS for marine taxa
Editorial text: written by Bioestrecho
Last revised: 8 September 2026

Parasitic Jaeger

Presence in the Strait

Identification

Movements

Ring recoveries

Gallery