[4] Known by locals as pata pegada or "web-footed one", Galápagos petrels are highly adapted to the ocean and spend most of their time at sea eating invertebrates and fish.

[5][6] The populations of Galápagos petrels have declined substantially over the last three generations (60 years) due to anthropogenic disturbances.

[5][1] Introduced predation (i.e. feral cats, dogs, pigs, and rats) and agricultural expansion have decreased the species' overall breeding success, survivability, and quality of habitats and nesting colonies.

[8] They are large, long-winged gadfly petrels with an overall dark-gray topside which darkens gradually towards the tip of the wings and tail.

[8] In contrast, their face and underparts are white, but the underwings have black margins and a diagonal bar that extends from the coverts to near the base of the wings.

[6][8] Although adult petrels sometimes acquire a brown tinge due to abrasion, their feathers remain relatively similar throughout the year.

[6] One of the most remarkable features in this group, however, is that all have external tubular nostrils, suggesting that they have developed an ability to smell, detect and locate their food.

[6] Although they are now widely distributed around the world, it appears to have differentiated from the other Procellariiformes over 40-50 million years ago in the Southern Hemisphere.

However, their genetic variation, their geographical separation and their morphological and behavioral differences provided enough evidence to split them into two unique species.

[2][7] Plus, recent studies found that some genetic, morphometric and behavioural differences also exist among individual island populations of the Galápagos petrel.

[6] The nesting colonies are distributed among five islands: Santiago, Floreana, Isabela, Santa Cruz, and San Cristobal, which are all less than 170 km apart.

[11] Nowadays, the Galápagos petrels commonly nest on offshore islets because their habitats have been destroyed or displaced by anthropogenic disturbances.

[5] Most can also be found in thickly vegetated sites where the soil is soft enough to burrow deep cavities, but some individuals also choose to nest in volcanic crevices.

[6] The Galápagos petrels are highly philopatric, meaning that every year they return to their natal colony or the same nesting site with the same partner.

[6][9] Courtship also occurs in the night and the petrels are often seen towering into the sky and flying erratically as a display to attract a female.

[6] Galápagos petrels are adapted to make efficient use of food resources which are typically distant from the colonies, patchily distributed and have low nutritive value.

[9] This much energy is required in young birds to develop their thermoregulatory ability, and their mass-specific metabolic rate is also the highest during that time.

Most gadfly petrels tend to remain silent at sea, but become very vocal at night when they are near their breeding colony.

[6] Moreover, from the inside of their burrow, they typically produce different crooning or growling notes and some moaning cries.

[6] They exhibit elaborate courtship flights that include aerial chasing, high-speed swoops, and towering which are accompanied by loud calls.

[5][6] During this time, which lasts approximately two weeks, each of the pair will pay short visits to the nest so that others do not think it is deserted.

[5] While the incubating parents are losing an average of 10-15 g per day, the others are foraging at sea with no evidence that they return to feed their partners.