Faraaz Abdool puts the spotlight on the bird whose habitat is the mid-Atlantic and breeding ground the rocky islands off Tobago’s north.
The Sargasso Sea in the Atlantic is unique among all other seas as all its boundaries are oceanic. While the body of water itself was named after the ubiquitous sargassum seaweed found within it, there is a small, cryptic seabird that now carries this name: the Sargasso shearwater. Its scientific name – Puffinus lherminieri – is in honour of the Guadeloupe-based French naturalist Félix Louis L’Herminier, who, with his son in his later years, spent considerable time studying the flora and fauna of the Caribbean.
Sargasso shearwaters are pelagic birds, meaning that they are superbly adapted to life on the ocean. They are from the order of birds colloquially known as “tubenoses” which comprises four families of ocean wanderers: shearwaters, albatrosses, petrels, and storm-petrels. They are so named for their tube-encased nostrils laying on top of their bills.
While all members of this group of seabirds have these distinctive tubes, they tend to be much more pronounced on the smaller species – which are also the species that typically nest in burrows. This correlates with an enhanced sense of smell that the birds use to locate their nests, and also to find plankton in what we perceive as a featureless ocean. Larger tubenoses such as the various species of albatross are typically surface nesters, and would build their nests in open areas. All tubenoses nest on remote, inaccessible offshore islands that are devoid of terrestrial predators.
[caption id="attachment_1150039" align="alignnone" width="1024"] Juvenile Sargasso shearwaters can look much larger than the sleek adults, as they are fat and covered in fluffy down feathers. [/caption]
Sadly, most of this group of seabirds are threatened with extinction. Whether by plastic ingestion, the presence of invasive predators on their breeding grounds, or by light pollution impacting their nocturnal breeding habits, these contemporary threats are an extension of our historically damaging relationship with them. While tubenoses in general have a cosmopolitan distribution, some of the individual families are limited to specific regions. All of them, however, are wholly dependent on a life at sea.
Shearwaters are some of the smaller members of this group of tubenoses, and they carve their livelihood in mostly temperate and cold-water regions of open ocean across the planet. In this vast habitat, they sometimes follow whales to feed on fish that have been disturbed by their passing – not unlike egrets that follow large terrestrial mammals as they traverse the land.
Shearwaters are competent swimmers and are famous for their habit of underwater pursuit. Using a combination of strong wings and webbed feet, they have been known to follow their intended quarry to depths of over 200 feet. They will not refuse easier or more straightforward options, however, and often pick up food from the surface or just below.
Their marine prowess
