The Blue-footed Booby is a true seabird—confined to marine habitats—although most birds spend their lives near the coast rather than in more distant pelagic (open-ocean) waters. Resting and roosting birds come near shore or onto shore, where they perch on rocks or other stable platforms. Unlike Red-footed Boobies, they perch only infrequently on ships’ rigging. They nest on arid, rocky islands with little vegetation.Back to top
Blue-footed Boobies eat mostly fish and squid. Anchovies, sardines, mackerel, flying fish, and other small fish form most of the diet; the larger female boobies take larger fish, on average, than males and can dive more deeply than males. Blue-footed Boobies catch fish by diving during daylight hours. From heights of up to 80 feet in the air, they dive as deep as 65 feet (15 feet is a more typical diving depth). Even when going after discards from fishing boats, these birds usually dive to catch the offal, plunging beneath the food and snapping it up in the bill as they ascend in the water.Back to top
The nest is set on the ground in a flat sandy or rocky coastal area.
The nest is a bowl-shaped scrape ringed by feces, called guano.
|Clutch Size:||1-3 eggs|
|Egg Description:||Pale bluish.|
|Condition at Hatching:||Helpless with little down.|
Blue-footed Booby courtship recalls the stylized rituals of albatrosses, though it is not quite as complex. Males select and defend a small nesting territory and land near the potential nest site with their remarkable blue feet spread out in display against their pale bellies. They then march around in an exaggerated fashion, raising the spread feet up and outward. Females also display their feet to prospective partners, and males appear to select females with brighter feet (and vice versa). The pair selects the nest site together within the male’s territory. Nesting birds sleep together at the nest; one parent at a time goes to sea to feed, and they take turns incubating the eggs. Males also sometimes destroy eggs, possibly when paternity is in question; the larger females regularly mate with males other than their partners (in about half the pairs studied). Eggs hatch about 4 days apart, with the result that the older chicks are much larger than their siblings and sometimes attack them. Nestlings can also be attacked by other species of booby, such as Nazca Booby, that nest in the vicinity. When foraging, Blue-footed Boobies execute swift dives, after which they mostly return immediately to the water’s surface, but they also can swim using their wings underwater, in pursuit of prey.Back to top
Most of the Blue-footed Booby's range lies outside of the U.S. and Canada. Partners in Flight rates the species a 15 out of 20 on the Continental Concern Score and includes it on the Yellow Watch List for declining populations. The North American Waterbird Conservation Plan estimates about 90,000 birds breed in the Gulf of California between Baja California and mainland Mexico. The largest breeding population of Blue-footed Boobies is in the Galápagos archipelago, where they are protected and where populations fluctuate but have been stable over the long term. Because of the large population worldwide and very large range, the species is categorized as Least Concern by the International Union for the Conservation of Nature. As is true of many seabirds, Blue-footed Boobies may be harmed by climate change and the effects of warming and acidifying waters on ocean food webs.
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Hernández Díaz, J. A., and E. N. Salazar Gómez (2011). Blue-footed Booby (Sula nebouxii), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.
Kushlan, J. A., M. J. Steinkamp, K. C. Parsons, J. Capp, M. A. Cruz, M. Coulter, I. Davidson, L. Dickson, N. Edelson, R. Elliott, R. M. Erwin, S. Hatch, S. Kress, R. Milko, S. Miller, K. Mills, R. Paul, R. Phillips, J. E. Saliva, W. Sydeman, J. Trapp, J. Wheeler and K. Wohl (2002). Waterbird conservation for the Americas: The North American waterbird conservation plan, version 1. Washington, DC, USA.
Palmer, R. S., Editor (1962). Handbook of North American Birds. Volume 1: Loons Through Flamingos. Yale University Press, New Haven, CT, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.