Its feet really are that blue, and the shade is a running health report that its mate keeps checking. The blue-footed booby is the star of Galápagos documentaries, but some small islands in Mexico’s Gulf of California hold a major share of the world’s population.
A slim, brown-and-white seabird with long, pointed wings, a wedge-shaped tail, a long, pointed grayish-blue bill, yellow eyes and bright blue feet. The pale head and neck are finely streaked grayish brown, the back is brown and the belly white, with a white patch on the hindneck and a narrow white band across the rump. Females are larger, on average about 27% heavier, and their pupil looks bigger and star-shaped; the sexes also sound different, the female’s voice deeper and coarser, the male’s much weaker. Young birds are browner, with darker streaking on the head, neck and chest and dull, brownish feet instead of bright blue ones.
Blue-footed boobies live in the eastern Pacific from the Gulf of California to northern Peru, including the Galápagos. In Mexico they nest on Gulf of California islands such as San Pedro Mártir, San Pedro Nolasco, San Jorge, San Ildefonso and Farallón de San Ignacio, and on the Pacific side at Isla Isabel, the Marías, the Marietas and San Benedicto. They nest on the ground on arid, rocky islands with little vegetation, in a shallow scrape ringed with guano. They aren’t true migrants, but young and non-breeding birds wander, sometimes as far as California.
They feed on anchovies, sardines, mackerel, flying fish and other small fish, plus squid, often fishing in flocks. Females lay one to three pale bluish eggs and both parents incubate. The eggs hatch about four days apart, so the oldest chick is much bigger than its siblings and sometimes attacks them; when food runs short, its attacks intensify and a younger chick may starve or be pushed out of the nest.
The blue comes from carotenoid pigments in a diet of fresh fish. On Isla Isabel, Nayarit, males deprived of food for 48 hours showed duller feet, and their feet brightened again within 48 hours of being fed fresh fish.
Source ↗In the same study, researchers made males’ feet look duller with makeup after the first egg was laid. Their mates responded by laying a smaller second egg than control females did.
Source ↗When paired with dull-footed females, males spent more time incubating, but only when the eggs were large; they spent less time on small eggs laid by dull females.
Source ↗Thirty years of data from Isla Isabel show the first chick starts attacking its siblings at 5 to 9 days old and keeps it up the whole nesting period. Brood reduction rises sharply when sea surface temperature climbs above 27.4 °C and food gets scarce.
Source ↗Isla San Pedro Mártir’s blue-footed booby colony, estimated at 110,000 pairs in 1991–93, was considered one of the largest in the world. Nest counts in 2020–2022 found only a small fraction of that.
Source ↗Birds from the Gulf of California subspecies sometimes irrupt north: California recorded 32 in 1969 and at least 45 in 1972, and 71 of 82 accepted state records from 1972 to 2003 were at the Salton Sea.
Source ↗Around Cabo the booby you’ll see most often is the dark brown booby with the white belly; blue-footed boobies are less common at the tip of the peninsula but do turn up around the Arch and in Bahía San Lucas. Watch for them diving over bait: they plunge from as high as about 24 m, can reach depths of about 20 m (around 4.5 m is more typical) and often fish in flocks, sometimes with hundreds hitting a school of baitfish at once.
If a booby grabs your bait, don’t lift it by the line. Reel it in slowly and gently, using a dip net if you have one, get control of the bill first, since seabirds peck, and cover its head and eyes with a cloth without blocking its breathing. Cut off the barb and back the hook out; if the hook is swallowed, cut the line as close to it as you can and leave it in place. A seriously injured or deeply hooked bird should be reported to the authorities (PROFEPA in Mexico).
| Mexico (NOM-059) | Subject to special protection (Pr) (2019 update) |
|---|---|
| Ley General de Vida Silvestre, art. 85 | Species at risk may only be taken with authorization, giving priority to restoration, repopulation, reintroduction and research |
| Federal Penal Code, art. 420 | 1 to 9 years in prison for unlawfully capturing, possessing or harming a species subject to special protection |
| Islas del Golfo de California | Flora and fauna protection area, part of a UNESCO World Heritage Site (2005) of 244 islands, islets and coastal areas; some of its small islands hold a major share of the world’s blue-footed boobies |
| IUCN Red List | Least Concern |
| United States | Protected under the Migratory Bird Treaty Act |
The dark booby common around Cabo, long called the brown booby (Sula leucogaster) and treated since 2024 by the American Ornithological Society as the Cocos booby (Sula brewsteri), is dark brown above and on the chest, sharply cut off from a white belly, with yellowish feet; males in Baja waters have a paler, whitish face. The red-footed booby is the smallest booby, with bright red feet and a colorful bill and throat pouch. The Nazca booby is a white booby much like the masked booby, but with an orange-pink bill instead of a yellow one. The brown pelican also plunge-dives, but it’s far bigger and bulkier, with a huge pouched bill.
Yes. They’re listed as subject to special protection (Pr) in NOM-059-SEMARNAT-2010, so capturing, keeping or harming one without authorization is a federal offense.
The color comes from carotenoid pigments in the fresh fish they eat. Well-fed, healthy birds have brighter feet, and mates use that shade to judge each other.
Yes, but they’re less common than the brown booby at the tip of the peninsula. Look around the Arch and over bait schools in the bay; the big colonies are farther north in the Gulf of California.
Top illustration: Top Anglers. Photos: iNaturalist contributors, credited on each photo.
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