Thalasseus albididorsalis
Silhouette: JJ Harrison (vectorized by T. Michael Keesey) · PhyloPic
In 3 days ~10% in a week ~30%
The West African crested tern (Thalasseus albididorsalis) is a bird species in the family Laridae. Until 2020 it was considered a subspecies of the New World royal tern, Thalasseus maximus. The West African crested tern was long thought to be a subspecies of royal tern. A study published in 2005 showed that it is more closely related to the lesser crested tern (Thalasseus bengalensis), and a 2017 publication confirmed and expanded on those results.
The West African crested tern is one of the three larger crested terns, along with royal tern and greater crested tern. Its tail is shallowly forked and the adult's bill is long and orange. It is about 50 cm (20 in) long, with a wingspan between 125–135 cm (49–53 in), and weighs 320–440 g (11–16 oz) with a mean weight of 367 g (12.9 oz). In breeding plumage its underside is white and upper parts silvery grey; the top of the head is black with a shaggy crest at the rear. As in all Thalasseus terns, the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dakar | 🇸🇳 Senegal | |
| 2 | Luanda | 🇦🇴 Angola | |
| 3 | Freetown | 🇸🇱 Sierra Leone | |
| 4 | Serrekunda | 🇬🇲 Gambia | |
| 5 | Accra | 🇬🇭 Ghana |
Rare
Under 5% of wildlife watchers report a West African Crested Tern sighting in Serrekunda on a given day, based on 38 verified sightings from GBIF citizen-science data. It is the 131st most-seen of the 213 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 and December–January
In those months about 10% of wildlife watchers report a West African Crested Tern in Serrekunda on a given day, against under 5% in February–March and May–November, the lowest months. Those are among Serrekunda's driest months, with almost no rain against 290 mm in August.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most West African Crested Tern sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 5
Of the 5 cities where we can rate West African Crested Tern sightings, Serrekunda ranks 4th at under 5%. The best odds are in Dakar (Senegal, about 40%), Luanda (Angola, about 10%) and Freetown (Sierra Leone, about 10%).
GBIF citizen-science records
It is estimated from how often the West African Crested Tern is recorded against all the birds logged in Serrekunda (38 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.
