• Magnificent frigatebirds in Barbuda's mangroves

    A white-headed juvenile magnificent frigatebird perches beside a fully inflated male in Barbuda's mangroves. (Photo courtesy Antigua & Barbuda Tourism Authority)

Hundreds — or maybe it’s thousands — of pterodactyl-shaped magnificent frigatebirds wheel overhead, skim the water beside us and balance on virtually every branch in the surrounding mangroves. So many males are puffing out their fat crimson throats to attract females, the more distant trees look like they’ve been decked out for Christmas. Barbuda’s Codrington Lagoon National Park, a short boat ride from the longest unbroken beach in the West Indies, is home to one of the world’s largest magnificent frigatebird colonies — a true wildlife spectacle hidden in what seems like an unlikely place. This is not the island I expected.

Antigua to Barbuda by catamaran

The Excellence, Tropical Adventures Antigua's day-tripping catamaran

The Excellence on Barbuda's 17-Mile Beach, the ocean side of the sandy strip bordering Codrington Lagoon and the conservation area that hosts the island's huge magnificent frigatebird colony. (Photo courtesy Antigua & Barbuda Tourism Authority)

Follow the boundary between the Caribbean Sea and Atlantic Ocean 40 kilometres north from St. John’s, Antigua — 1½ hours on the Excellence, Tropical Adventures Antigua’s bouncing, sea-spraying, rum-punch-stocked catamaran, which is how I travelled — and you reach Antigua’s sister island of Barbuda, a flat, green jewel with a population of just 1,800 and no more than a handful of tourists at any given time.

On this October afternoon, that solitary scattering of visitors is us. After disembarking and enjoying a swim on famed 17-Mile Beach, we’re invited to turn inland across the sand strip, narrow enough to throw a conch shell over, to the edge of massive Codrington Lagoon. There, as part of the Tropical Adventures Antigua “Barbuda by Sea” excursion, local guides with small speed boats and big smiles await. We strap PFDs around our torsos and motor off to find out what a “frigatebird” is.

Barbudan guides on the edge of Codrington Lagoon

Barbudan guides prepare to ferry visitors into the mangroves of Codrington Lagoon National Park. (Photo courtesy Antigua & Barbuda Tourism Authority)

Into the bird sanctuary

As small, shrubby islands begin to appear out of the brackish water, the lagoon takes on a dank, vaguely methane smell. In the denser mangroves where our guides tie up to buoys, the odour is also fishy — the result of the dietary preference of the giant black seabirds that throng the lagoon’s northwest corner, where they come to mate and nest every year between September and April. When the guides silence their motors, we’re surrounded by the birds’ amorous “drumming” and clicking sounds, their wheezing, grating signals.

Lead guide Tetworth Richardson stands in his boat to tell us about this place, a Wetland of National Importance and a national park since the early 1980s. The lagoon is home also to brown boobies, laughing gulls, the threatened Barbuda warbler, critically endangered leatherback and hawksbill turtles and many other species, but the most charismatic of them all are the magnificent frigatebirds, national bird of Antigua and Barbuda.

More than 5,000 nest here, says Richardson. “And it’s early in the season,” he adds, “so you can see the black-headed females hoverin’ above, checkin’ out the groups of males, who are inflatin’ their red throats, wavin' their necks and clickin’ their beaks to say ‘C’mon down girls!’ ”

When a female chooses her mate, the pair settle onto a bough to meet and neck for a while; then, the male deflates himself and flies away to collect sticks and other materials for their nest, which he gives to the female to use in construction.

A male magnificent frigatebird in Codrington Lagoon National Park

In the mangroves of Codrington Lagoon every fall, thousands of male magnificent frigatebirds do their best to attract females. (Photo courtesy Antigua & Barbuda Tourism Authority)

This intricate romance is unfolding, in various stages, all around our boats, although even without the courtship antics the birds would be a thrilling sight. Their great pointed wings — which at more than two metres across are wider than those of Canada geese, sandhill cranes and even golden eagles — allow them to soar for weeks at a time at sea. To Barbudans these are “Man O’ War” birds, a name given for their tendency to aggressively, acrobatically chase down slower birds and force them to drop the fish and other food in their bills.

Soon we return to the Excellence and the sort of brilliantly blue ocean one envisions before a trip to Antigua and Barbuda. It’s curious, on first visit, that Barbuda remains undeveloped; only a couple of beach resorts operate on its shores and there are relatively few restaurants or other attractions to entice visitors to stay in Codrington, the island’s sole community. Even so, after visiting the pristine, buzzing wildlife sanctuary in Codrington Lagoon and wandering empty, peaceful kilometres of white and coral-pink beach, you can’t help but hope it remains a well-kept secret.