Order Suliformes Family Sulidae
Family Sulidae is comprised of the gannets and boobies. One way to differentiate gannets from boobies is that gannet feathers extend forward of the eyes, while booby feathers stop at the eyes.
These seabirds are medium to large and inhabit coastal areas. Boobies are colonial breeders found on islands and coastlines. During courtship, they engage in a behavior known as “parading,” where they exaggeratedly raise and flaunt their feet to attract a partner. They typically lay one or more chalky blue eggs either on the ground or occasionally in a tree nest.
They dive and swim efficiently underwater, using their streamlined bodies to catch prey. Like pelicans, they have special glands that produce a waxy substance, which they spread on their feathers to keep them waterproof. Their legs are strong and feature webbed feet with webbing between all four toes. In some species, the webbing is brightly colored and is used in courtship displays.
Their bills are typically long, brightly colored, deep at the base, and pointed, and they have long, wedge-shaped tails. Their eyes are on either side of their bills, providing them with strong binocular vision. They are all adapted for long-distance flight, featuring long, narrow wings and slender bodies, allowing them to travel thousands of kilometers.
1. Genus Papasula
There is only one species in this genus.
1.1. Abbott’s Booby (Papasula abbotti)
Description: Abbott’s Boobies have slender shapes and long white underwings with black tips. Their bodies are primarily white, featuring black upper wings adorned with white spots. Additionally, they have black patches on their thighs and tails. Their dark brown eyes are accentuated by dark facial skin around them, which gives the appearance of larger eyes. Their eyelids are a lighter gray. The bills of Abbott’s Boobies are bluish-gray, often with hints of pink and black tips, and their legs and feet are also blue-gray. Females are similar but have pink bills with black tips.
- Length – Average 30 inches (75 cm)
- Weight – Average 2.2 lb. (1000 g)
- Wingspan – 74.8 – 98.4 inches (190 – 250 cm) –
Habitat: Abbott’s Boobies inhabit marine and pelagic. They breed in the canopies of the rainforests on Christmas Island.
Conservation: IUCN has listed Abbott’s Booby as Endangered (EN) due to the Loss and degradation of habitat due to mining and road building.
Distribution: Abbott’s Boobies can be found on the Australian territory of Christmas Island in the eastern Indian Ocean.
2. Genus Sula
2.1. Blue-footed Booby (Sula nebouxii)
Description: Blue-footed Boobies are named for their bright blue feet. They have white lower bodies, light brown necks, and heads with white streaks. Their wings are long and pointed, with white patches on the back of their necks and narrow white bands across their rumps.
Females are similar to males but are slightly larger, and their feet are brighter blue.
- Length – Average 32 inches (81 cm)
- Weight – Average 3.3 lb. (1496 g)
- Wingspan – Average 60.24 inches (152 cm)
Similar to: Peruvian Booby. Adult Peruvian Boobies have pure white heads, neck; adult Blue-footed boobies have brown heads with white streaks. Juvenile Blue-footed Boobies have brown wings with no white; juvenile Peruvian Boobies have darker brown wings with some white on them.
Habitat: Blue-footed Boobies live mostly in the ocean but stay close to land. They are rarely found in inland lakes. They breed along rocky coasts.
Conservation: IUCN has listed Blue-footed Boobies as Least Concern (LC).
Distribution: Blue-footed Boobies live along the coasts of the eastern Pacific Ocean. You can find them from California to the Galápagos Islands and down to Peru.
2.2. Brown Booby (Sula leucogaster)
Description: Brown Boobies have mostly brown feathers with white on their chests, bellies, vents, and undertail coverts. Their underwings have white secondary and axillary feathers, while the rest are dark brown. Their bills are pale yellow to greenish yellow at the base, changing to pale pink or horn color at the tips, but can also be blue at the base. The skin around their pale gray eyes is blue, and their feet are yellowish to yellowish green. Females are slightly larger with greenish-yellowish bills.
- Length – 23.6 – 31.5 inches (60 – 80 cm)
- Weight – Average 2.2 lb. (1000 g)
- Wingspan – 51.97 – 61.02 inches (132 – 155 cm)
Similar to: Masked Booby. Juvenile Masked Boobies have brown heads and necks; adult Brown Boobies have darker brown heads, necks, and upper breasts.
Habitat: Brown Boobies are exclusively marine birds, only needing land to breed.
Conservation: IUCN has listed Brown Boobies as Least Concern (LC).
Distribution: Brown Boobies are found along the coasts of the eastern Pacific Ocean. Their range extends from California to the Galápagos Islands and further south to Peru.
2.3. Masked Booby (Sula dactylatra)
Description. Masked Boobies are the largest species of booby birds. They primarily have white plumage with black coloring on their wings and tails. These birds have distinctive black masks at the base of their stout yellow bills, and their eyes range from yellow to orange. Their feet come in various colors, including dull greenish, gray-brown, and greenish-yellow hues. Females are slightly larger than the males.
- Length – 30 – 33 inches (75 – 85 cm)
- Weight – 2.6 – 4.9 lbs. (1200 – 2200 g)
- Wingspan – 63 – 73 inches (160 – 170 cm)
Similar to:
- Australasian Gannet. Australasian Gannets have yellow on their heads; Masked Boobies do not. Gannet feathers occur forward of the eyes; booby feathers stop at the eyes.
- Brown Booby. Juvenile Masked Boobies have brown heads and necks; adult Brown Boobies have darker brown heads, necks, and upper breasts.
- Nazca Booby. Nazca Boobies are mainly found on Galapagos Islands; Brown Boobies have larger ranges. Nazca Boobies bills are orange at the bases and darker than the yellow base of Masked Booby.
- Northern Gannet. Masked Boobies have blacker on their wings than Northern Gannets, which only have black wing tips. Gannet feathers occur forward of the eyes; booby feathers stop at the eyes.
- Red-footed Booby. In flight, Red-footed Boobies can be distinguished from Masked Boobies by their all-white tail. But the black-tailed morph of Red-footed Booby can be problematic to distinguish in flight.
Habitat: Masked Boobies are exclusively marine birds, only needing land to breed.
Conservation: IUCN has listed Masked Boobies as Least Concern (LC).
Distribution: Masked Boobies are found across tropical oceans between the 30th parallel north and the 30th parallel south. They occur in North America, South America, Europe, Asia, Africa, and Australia.
2.4. Nazca Booby (Sula granti)
Description: Nazca Boobies are large seabirds. They primarily have white plumage with black coloring on their wings and tails. These birds have distinctive black masks at the base of their stout, deep red or orange bills, and their eyes range from yellow to orange. Their feet vary in color, including dull grayish or olive hues. Females are bigger and heavier than males, with darker purple feet.
- Length – 31.89 – 35.04 inches (81 – 89 cm)
- Weight – 2.26 – 2.68 lbs. (1025 – 1216 g)
- Wingspan – 59.84 – 66.93 inches (152 – 170 cm)
Similar to the Masked Booby. Nazca Boobies are primarily found on the Galapagos Islands, while Masked Boobies have a larger range. The bills of Nazca Boobies are orange at their bases and darker than the yellow bases of Masked Boobies.
Habitat: Nazca Boobies are exclusively marine birds. They nest near cliffs on bare ground with little to no vegetation.
Conservation: IUCN has listed Nazca Boobies as Least Concern (LC).
Distribution: Nazca Boobies inhabit the eastern Pacific, ranging from Baja California to the Galápagos Islands, Isla de la Plata in Ecuador, and Malpelo Island in Colombia.
2.5. Peruvian Booby (Sula variegata)
Description: Peruvian Boobies are distinctive with snow-white heads and necks and dark upperparts with white scaling on the back. Their wings have brown feathers and white feather markings on the tips (appear mottled). Their eyes are deep red, and their long, pointed bills and legs are distinctly gray. Females are slightly larger than the males.
- Length – 27.95 – 29.92 inches (71 – 76 cm)
- Weight – 2.84 – 3.40 lbs. (1290 – 1543 g)
- Wingspan – Average 59.1 inches (150 cm)
Habitat: Peruvian Boobies are exclusively marine birds. They primarily nest on cliffs, rocky islands, and coastal ledges along the Humboldt Current.
Conservation: While IUCN has listed Peruvian Boobies as Least Concern (LC), they have faced declines during El Niño events, which disrupted their food supply (anchovies).
Distribution: Peruvian Boobies are found along the coastlines and coastal waters of the Humboldt Current off the western coast of South America.
2.6. Red-footed Booby (Sula sula)
Description: Red-footed Boobies are the smallest type of booby. They are named for their bright red legs and long, wedge-shaped tails. There are three color variations: the white morph, the black-tailed morph, and the brown morph. The white morph has mostly white feathers, black outer wings, and white tails. The black-tailed morphs look similar to the white morphs but have black tails. The brown morphs have all-brown feathers.
Red-footed Boobies have bills and throat pouches that display pink and blue hues. Males have lime green or bluish-green patches located under and in front of their eyes before breeding; however, this patch quickly fades after incubation begins. Aside from these differences, males and females look quite similar.
- Length – Average 28 inches (70 cm)
- Weight – Average 1.845 lbs. (837 g)
- Wingspan – Average 60 inches (152 cm)
Habitat: Red-footed Boobies are exclusively marine birds. They breed in colonies along coastal regions, preferring islands as nesting sites.
Conservation: IUCN has listed Red-footed Boobies as Least Concern (LC).
Distribution: Red-footed Boobies are found in tropical and sub-tropical waters across the globe, which include the Oriental, Ethiopian, Neotropical, and Australian regions; they are also found on oceanic islands. One of the largest populations is on the Galapagos Islands.
Conclusion
Boobies are incredible marine hunters that mainly eat fish and squid. They spend a lot of time in the oceanic areas and do not spend much time on land, so they have few predators. Most of the booby species are successful, having exceptionally vast ranges and stable populations, and only the Abbot’s Booby is endangered in parts of their range.
Studying these birds helps us understand marine ecosystems because they impact the fish they eat. It is impressive to see how they adapt to their surroundings. Their presence in different habitats shows why we must protect these amazing creatures and their environments. Protecting them helps keep the balance of marine life.
