Dubbed “booby” by Capt. Bligh’s crew, the Masked Booby is not stupid. It uses intelligence and “hidden Markov models” to flourish amid uncertainty on the high seas.
By Rex Graham
According to maritime lore, the crew of the Bounty boasted that they easily captured the large white seabirds on the deck of the Bounty. The Booby name stuck. It’s part of avain taxonomy. Boobies are most closely related to the fellow plunge-diving Gannets.
Researchers have discovered that Masked Boobies use a highly flexible and complex algorithm-like approach to survival and feeding their young. They are now studying Booby behavior to unlock the secrets of their hidden Markov models.
For example, Boobies remember where they’ve found fish before, but they are quick to seize new opportunities. Their strategy is nimble and nuanced. Corporations could learn from them.
For example, Masked Boobies continually adjust their short- and long-distance foraging as their and their chicks’ energy requirements change. (The typical clutch is 2 eggs, but the dominant chick usually kills its weaker sibling.) The parents factor in geographic fish abundance and size. They know when and at what depth food can be caught. During the El Nino event of 1982-83 when fish abundance plummeted in the Pacific, Masked Boobies on the Galapagos Islands scrapped their usual plans, which “resulted in a complete cessation of the reproductive activity.”
Masked Boobies and other seabirds also factor in minor ecological changes. They remember positions of current upwellings (where fish abundance can be high) while sometimes taking shorter, less productive trips to better meet the needs of their chicks. Researchers are struggling to mathematically describe all of it.
“Such foraging plasticity has previously not been reported in this species,” Australian, German and French researchers said in 2015 in the Journal of Experimental Marine Biology and Ecology.
A 33-day birding voyage from the sub-Antarctic to the northwest coast of Africa offers great opportunities to see Masked Boobies and other seabirds that form large nesting colonies on small, isolated volcanic islands. “Many remain inaccessible and uninhabitable to all but the most unique wildlife,” said Quark Expeditions, which specializes in oceanic birding and wildlife voyages.
Eco-tourists who go ashore are advised to keep their distance. Boobies are used to being left alone, which explains their tameness on the Bounty. However, even well-meaning tourists who approach nests too closely make Booby parents jittery. They vocalize more and more frequently turn their heads and bodies. Sometimes, they fly from a human disturbance, which exposes eggs and chicks to danger.
On many islands, feral cats have decimated by boobies. Rats are even worse.
The largest in its genus, Sula, the Masked Booby is broadly distributed at low, Tropical latitudes. One population lives in the Indian Ocean south of India and east of Africa. A second population lives in the Atlantic and Pacific. The 2 groups became genetically isolated about 115,000 years ago, separated by continents and ocean expanses with no islands. Masked Boobies are found throughout the Caribbean Sea and occasionally along the coast of Florida or farther north.
Continents are barriers to their movement: they would starve if they flew very far over land. Even on oceans, boobies must learn the local habits of relatively unpredictable fish. The knowledge is valuable. They don’t venture very far.
They nest near cliff edges so they can glide down to reach flight speed. Their nests are circles of accumulated guano plaster. These white “signatures” are visible on Google Earth images. Ascension Island in the South Pacific has one of the strongest signatures.
“We encourage wildlife managers to view their study sites on Google Earth for evidence of their target species,” U.K. researchers said in the journal Wildlife Biology.
Non-breeding and juvenile boobies are often seen hundreds of km from any land, which may be party why they sometimes rest on ships.
Masked Boobies are fast fliers, but Frigatebirds combine speed, maneuverability and malevolence. This is bad news for boobies.
Frigatebirds can be patient. They hang back at islands, gliding effortlessly on huge wings, while boobies are busy far out at sea. Masked Boobies catch bigger fish than other Boobies, and Frigatebirds know they offer a bigger potential payoff.
Bird photographers and videographers like to film the encounters. Frigatebirds are part of a kleptoparasite fraternity, which including sheathbills, skuas, gulls and terns. However, Frigatebirds are the most specialized.
Their chase and harass Boobies to such a degree that they regurgitate fish in mid-air. Frigatebirds even seize Boobies in the air and release them only when a fish is regurgitated.
To get past the Frigatebird gauntlet, some Boobies fly in low and fast. Most circle high above and plunge past their fish-stealing nemesis to their chicks. To escape, Boobies land on the ground or water, or outmaneuver Frigatebirds to such a degree that they break off the attack.
“Of 325 chases on Masked Boobies, 52 were successful and resulted in the Frigatebird obtaining food,” researchers at University of East Anglia and Cambridge University said in the journal The Condor.
Animal behavior researchers and mathematical modelers have designed something called “hidden Markov models” to try to understand the dynamics of how Manx Shearwaters shift from one “mode” of foraging to another. The goal is to discover “discrete behavioral states” that evade any observational scientist.
The models seek to recognize “temporal patterns” of a seabird’s mental states. These states change continually in individual birds. One bird’s temporal patterns may differ from another bird’s, depending on it reproductive status, distribution of fish, and many other factors.
It’s an exciting new area of research at the intersection of ornithology and mathematics, and one that will likely debunk any notion that the Masked Booby, or any seabird, is a dim-witted dummy.
“This type of behavioural mapping has high value for conservation planning, allowing better identification of the key areas and habitats where animals engage in specific types of behaviour,” researchers with the University of Oxford, the company CoMPEX, Microsoft, and British ornithologists said in 2016 in the Journal of the Royal Society Interface.