Hydrobates tristrami
The Tristram's Storm Petrel (Hydrobates tristrami) is a medium-sized, pelagic seabird distinguished by its overall sooty blackish-brown plumage and a deeply forked tail, a unique feature among most storm petrels. Measuring about 24-27 cm in length with a wingspan of 46-50 cm, it presents a subtle paler carpal bar on its upperwings, which, along with its size and tail shape, aids in identification at sea. Belonging to the family Hydrobatidae, or Northern Storm-Petrels, its closest relatives in...
Tristram's Storm Petrels are strictly pelagic, inhabiting the open ocean, only coming ashore to remote, predator-free islands and atolls for breeding, typically nesting at sea level within burrows or rock crevices.
Their diet primarily consists of small marine fish, squid, crustaceans, and plankton, which they obtain by surface-feeding and dipping, often utilizing oil slicks or discards from fishing boats.
These elusive petrels exhibit a dual daily activity pattern; they are strictly nocturnal at their breeding colonies to evade aerial predators, but are diurnal when foraging at sea. Their foraging strategy involves surface-skimming, dipping, and the characteristic 'walking on water' where they pat...
The Tristram's Storm Petrel's primary breeding grounds are concentrated on remote islands within the Northwestern Hawaiian Islands (e.g., French Frigate Shoals, Laysan, Kure Atoll) and the Ogasawara (Bonin) and Iwo (Volcano) Islands of Japan, with historical breeding reported on Wake Island. Foll...
Least Concern
- Tristram's Storm Petrel is named after Henry Baker Tristram, a notable English clergyman, explorer, and ornithologist of the 19th century. - It is one of the largest storm petrel species in the world, giving it a commanding presence over the open ocean. - Unlike many storm petrels, it possesses...