Oceanodroma castro
Silhouette: Richard Crossley · PhyloPic
In 3 days <5% in a week ~10%
The band-rumped storm petrel, Madeiran storm petrel, or Harcourt's storm petrel (Hydrobates castro) is a species of storm petrel in the family Hydrobatidae. The band-rumped storm petrel is 19–21 cm (7.5–8.3 in) in length with a 43–46 cm (17–18 in) wingspan, and weighs 44–49 g (1.6–1.7 oz). It is mainly brownish black with an extensive white rump. Similar to Leach's storm petrel with the forked tail, long wings, but Leach's has a more deeply forked tail, a differently shaped (V-shaped or triangular) white rump, and a 'tern-like' flight, whereas the band-rumped storm-petrel has a more 'shearwater-like' flight.
The species breeds on islands in the warmer parts of the Atlantic and Pacific Oceans. These include the Berlengas (a few tens of kilometres off mainland Portugal), the Azores, Madeira, Canary Islands and Saint Helena in the Atlantic, and in the Pacific off eastern Japan, on Kauai, Hawaii, and on the Galápagos Islands. In 2016, the species was reported to have also started breeding on the Mauna Loa volcano on the island of Hawaii.
Birds nest in colonies close to the sea in rock crevices and females lay a single... Wikipedia →
Recording0:35
Spain · 2024
© Adrián Pina · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Galápagos Islands | 🇪🇨 Ecuador | |
| 2 | Isla del Coco National Park | 🇨🇷 Costa Rica | |
| 3 | Cabo Blanco Absolute Nature Reserve | 🇨🇷 Costa Rica |
Rare
Under 5% of wildlife watchers report a Band-rumped Storm-Petrel sighting in Cabo Blanco Absolute Nature Reserve on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 205th most-seen of the 241 birds we can rate there. Over three days the chance rises to under 5%, and over a week to about 10%, if each day is a fresh chance.
May
In that month about 10% of wildlife watchers report a Band-rumped Storm-Petrel in Cabo Blanco Absolute Nature Reserve on a given day, against under 5% in June to April, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Band-rumped Storm-Petrel sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 3
Of the 3 parks where we can rate Band-rumped Storm-Petrel sightings, Cabo Blanco Absolute Nature Reserve ranks 3rd at under 5%. The best odds are in Galápagos Islands (Ecuador, about 10%) and Isla del Coco National Park (Costa Rica, under 5%).
Same genus: Oceanodroma
The closest relatives of the Band-rumped Storm-Petrel that you can see in Cabo Blanco Absolute Nature Reserve (genus Oceanodroma) are Wedge-rumped Storm-Petrel (about 10%) and Least Storm-Petrel (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Band-rumped Storm-Petrel is recorded against all the birds logged in Cabo Blanco Absolute Nature Reserve (11 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.
