Bioestrecho

Explore the life of the Strait

Two catalogues with species pages, birds and cetaceans: what crosses the Strait through the air and what crosses it underwater. Birds provide almost all the open observations; cetaceans very few, and that too tells the story.

Catalogue with species pages

Birds

369 species with a page

Almost all observations from the Strait are of birds.

How they are in the Strait

94 resident
123 seasonal
39 migrant
23 occasional
85 vagrant
3 historical
2 to confirm

See the birds catalogue

Catalogue with species pages

Cetaceans

16 species with a page

From the harbour porpoise to the blue whale.

The most observed

See the cetaceans catalogue

The map of the Strait

The explorer will bring together observations, habitats, bathymetry, protected areas and migration corridors on a single chart, with a time scale from 2000 to today.

Open the explorer

Each place opens the explorer centred on it

Now in the Strait

See everything happening now

Where to watch today

Forecast wind at Tarifa, 10:00–16:00

7km/h from the SW

Gusts

20 km/h

Calm: crossing along the whole front

With no dominant wind, soaring birds cross at any point between Tarifa and Gibraltar as soon as the thermals rise. It is the most spread-out day and the most comfortable for watching.

Watchpoint: Any; Cazalla and Algarrobo cover both ends

Forecast for Tuesday 8 September, Open-Meteo (CC BY 4.0). A reading, not a prediction of passage.

Seasonality

September is the peak of soaring birds heading south.

Photo: European Honey Buzzard, Alidz31, CC BY · Barn Swallow, Donald Davesne, CC BY · Northern Gannet, Brooke J., CC BY

Deduced from the migration calendar, not from today's observations.

Recent observations

Observations from the last few days will come from eBird and iNaturalist once their terms of use are settled.

Until then this block will show no sightings: presenting a historical record as recent would be the easiest mistake to make and the hardest to detect.

Latest data added: 8 September 2026

The cetaceans observed in the Strait

Full list taken from the OBIS checklist for the extended area. Sixteen species, from the harbour porpoise to the blue whale.

Everything that crosses has its hour

The Strait is not a place of constant passage but a calendar. Each group has its window, and in September the ones marked below coincide.

Representative species: European Honey Buzzard — peak passagepassage windowtodayPhoto: European Honey Buzzard, Alidz31, CC BY · Black Kite, Valentina Eggler, CC0 · Barn Swallow, Donald Davesne, CC BY · Northern Gannet, Brooke J., CC BY

Representative species: Black Kite — peak passagepassage windowtodayPhoto: European Honey Buzzard, Alidz31, CC BY · Black Kite, Valentina Eggler, CC0 · Barn Swallow, Donald Davesne, CC BY · Northern Gannet, Brooke J., CC BY

Bibliographic source, pending comparison with Fundación Migres

See the routes

Photograph: Alidz31, CC BY, via iNaturalist

Species of the moment

European Honey Buzzard

Pernis apivorus (Linnaeus, 1758)

Order: Accipitriformes
Family: Accipitridae
Presence: Migrant

No other species concentrates its passage so much. Six in ten observations of the honey buzzard in the Strait are from September, and one in four from August. In winter not a single one remains: they are all south of the Sahara.

J

F

M

A

M

J

A

59 %

S

O

N

D

Open observations in the area, 1972–2025.

See the full species page

Stories

Our own features and popular pieces. What the data reveals when given time.

Open data
The 30% of the Strait that cannot be published
917,015 records from the area carry a non-commercial licence. What is lost, and why losing it is worth it.
In preparation
Marine fauna
Sixteen cetaceans and a sill
Why the underwater step at Camarinal explains which whales enter the Mediterranean and which stay out.
In preparation
Migration
September, seen from Tarifa
Six in ten honey buzzards recorded in the Strait crossed in a single month of the year.
In preparation