Bermuda Cahow Watching Pelagic

The Bermuda Cahow Watching Pelagic is one of the world's most remarkable seabird experiences — a dedicated offshore boat trip into the open Atlantic south of Bermuda to watch the Bermuda Petrel (Cahow, Pterodroma cahow) at sea. Jointly organised by the Bermuda Audubon Society and the Bermuda Aquarium, Museum & Zoo (BAMZ), the trip departs from the BAMZ Aquarium dock in Flatts aboard the MV Endurance, guided by Dr Miguel Mejias, heading beyond Cooper's Point into the offshore waters south of the island. The Cahow is one of the great conservation stories of the 20th century: believed extinct since the early 1600s after centuries of persecution by colonists and introduced rats, a tiny colony was rediscovered on rocky islets off St. George's Parish in 1951. Under the stewardship of David Wingate and, later, Jeremy Madeiros, the colony has grown from just 18 breeding pairs in 1951 to over 120 pairs today — all on Nonsuch Island, a living museum restoration of pre-colonial Bermuda. The offshore watching trip captures the birds in their pelagic element: as dusk approaches, Cahows gather on the open ocean surrounding Nonsuch Island in a pre-landfall assembly, flying, calling, and displaying before slipping into their underground burrows under cover of darkness to avoid predation by gulls.

Bermuda occupies a uniquely productive position in the western North Atlantic — a volcanic seamount capped in limestone, rising abruptly from deep Sargasso Sea water to within 2 nautical miles of the surface. This dramatic bathymetric gradient, combined with the Gulf Stream's northward flow and the convergence of warm surface and cool deepwater masses around the Bermuda Platform, creates outstanding offshore birding conditions in every season. The offshore waters south of Bermuda are among the most reliable sites in the Atlantic for the Black-capped Petrel (Pterodroma hasitata, Critically Endangered, fewer than 2,000 birds globally, breeding only in Hispaniola's mountains), which feeds in the productive deep Gulf Stream and Sargasso Sea waters adjacent to the island. Wilson's Storm-Petrel (Oceanites oceanicus), the world's most abundant seabird, is a year-round presence offshore; Leach's Storm-Petrel (Hydrobates leucorhoa) and Band-rumped Storm-Petrel (Hydrobates castro) are also recorded. The White-tailed Tropicbird (Phaethon lepturus) breeds colonially on Bermuda's limestone cliffs and is a constant companion of any offshore trip.

Spring and summer months bring the shearwater spectacle: Cory's Shearwater (Calonectris borealis) is common and abundant May–October as birds from Canary Island and Azorean colonies disperse across the North Atlantic; Greater Shearwater (Ardenna gravis) is superabundant June–September as millions of birds breeding on Tristan da Cunha and Nightingale Island transit the western North Atlantic on their clockwise annual migration; Sooty Shearwater (Ardenna grisea) is regular May–September, and Manx Shearwater (Puffinus puffinus) occurs on passage. All three jaeger species (Pomarine, Parasitic, Long-tailed) can be encountered offshore in spring and autumn, together with South Polar Skua (Stercorarius maccormicki) on southward return in late summer. Brown Booby (Sula leucogaster) and Masked Booby (Sula dactylatra) occasionally accompany the pelagics, and Magnificent Frigatebird (Fregata magnificens) is a regular visitor to Bermudian waters.

The Bermuda Audubon Society (audubon.bm) also runs spring general pelagic birdwatching trips targeting migrating seabirds independent of the Cahow-specific events. All trips are subject to weather and sea conditions — the offshore waters south of Bermuda can be active and rolling seas should be expected; preventative measures are recommended for those prone to motion sickness. Minimum age is 10 years old. Upcoming dates for both Cahow watching and general pelagic trips are listed on the Bermuda Audubon Society events calendar at audubon.bm/events; tickets are also sold through Island Tour Centre at islandtourcentre.com.