Chroicocephalus serranus
Silhouette: Michael Scroggie · PhyloPic
In 3 days ~10% in a week ~30%
The Andean gull (Chroicocephalus serranus) is a species in subfamily Larinae of the family Laridae, the gulls, terns, and skimmers. It is found in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. The Andean gull was long placed in genus Larus. Genetic research has established that Larus sensu lato is paraphyletic so the American Ornithological Society, the International Ornithological Committee, and the Clements taxonomy moved it and 10 other gulls to genus Chroicocephalus. However, BirdLife International's Handbook of the Birds of the World retains all of them in Larus. The systems agree that the Andean gull is monotypic.
The Andean gull is 42 to 48 cm (17 to 19 in) long and weighs about 480 g (17 oz); it is one of the larger members of its genus. The sexes are alike. Adults in breeding plumage have a glossy black hood with a white crescent behind the eye and a mostly white body with a gray back and sometimes a pink flush on the underparts. Their tail is white. The upper side of their wing is mostly gray with an alternating white-black-white-black pattern on the primaries. The underside of their wing is pale gray with a blackish...
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Lauca National Park | 🇨🇱 Chile | |
| 2 | Paracas National Reserve | 🇵🇪 Peru |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | La Paz | 🇧🇴 Bolivia | |
| 2 | Cochabamba | 🇧🇴 Bolivia | |
| 3 | Lima | 🇵🇪 Peru | |
| 4 | Quito | 🇪🇨 Ecuador | |
| 5 | Arequipa | 🇵🇪 Peru |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Bioparque Municipal Vesty Pakos | 🇧🇴 Bolivia |
With luck
About 10% of wildlife watchers report an Andean Gull sighting in Paracas National Reserve on a given day, based on 27 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 61st most-seen of the 84 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
April–May, August, October and December
In those months about 10% of wildlife watchers report an Andean Gull in Paracas National Reserve on a given day, against under 5% in January–March, June–July, September and November, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Andean Gull sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 2
Of the 2 parks where we can rate Andean Gull sightings, Paracas National Reserve ranks 2nd at about 10%. The best odds are in Lauca National Park (Chile, about 50%).
GBIF citizen-science records
It is estimated from how often the Andean Gull is recorded against all the birds logged in Paracas National Reserve (27 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.
