Nearly always in motion in challenging habitats and with dozens of species sharing similar shapes, sizes and plumages, pelagic birds are difficult to identify confidently, but birders who understand the key features of seabirds can more easily distinguish between species and accurately identify any petrel, shearwater, albatross or other type of seabird they see.

Equipment to Identify Seabirds

While it is possible to see seabirds from land in some regions, most birders get their fill of these species through pelagic birding trips.

Birding from a boat in the open ocean requires special equipment to ensure the best views without the risk of losing tools or missing birds. To be prepared to watch seabirds, birders should have…

• Binoculars: Optics for pelagic trips should be waterproof or have good water-resistant coatings and cases. A wide field of view will help quickly sight birds, and high magnification will bring distant seabirds closer for better views of subtle field marks. Binoculars should be thoroughly secured with a harness or sturdy strap in case of rough waters or jostling, and a cleaning rag or damp cloth is essential to remove sea spray that can obscure views or damage delicate lenses. A spotting scope can be useful if viewing seabird colonies on land, but otherwise it will be too unwieldy to use on a moving vessel.

• Camera: A camera with a good zoom and high shutter speed can capture seabirds in flight so the photos can be analyzed later for more careful identification. Because it will be hard to use a tripod on a boat – and many pelagic tour operators do not permit tripods because of trip hazards – it is best to use a lightweight model and manageable lenses that can be carried by hand. A vest or coat with deep pockets is ideal for carrying equipment.

• Field Guide: A field guide is essential for any birding trip, and for pelagic birding, the guide should have an extensive seabird section. Illustrations or photos should include birds on the water and in flight. Range maps can help narrow down bird identification, and additional information about behavior, including flight style and feeding pattern, can be useful clues. It is best to review the guide thoroughly before birding, and a more extensive reference such as Petrels, Albatrosses & Storm-Petrels of North America can be an even better resource for learning how to identify seabirds.

• Seasickness Remedies: While pills or homeopathic remedies to combat seasickness won't make the birds come any closer or show their field marks more easily, they will ensure that birders don't lose valuable views because of queasy stomachs or dizziness. Similarly, sunscreen, proper attire and plentiful water are essential to make a pelagic trip as comfortable as possible.

Identifying Seabirds by Sight

Because many seabirds offer only quick views as they fly by during a pelagic trip, it is essential to know exactly what to look for to properly identify these birds. When a seabird is within view, watch for…

• Color: What color is the plumage? Are the upperparts and underparts different colors? How does the bird's color change as the light changes?

• Head: How large is the bird's head relative to its body? Are there any distinct markings or colors on the face or crown?

• Bill: How long is the bill compared to head size? How thick is it, and what color? What is the size of the hook at the tip, if it has one? Is the nasal tube especially prominent?

• Wings: What is the bird's wingspan? How are the wings shaped? What color is the wingpit? Are there other colors or markings, such as on the leading or trailing edges?

• Rump: Does the rump color contrast to the rest of the bird's plumage? How extensive is the color? How sharp is the line between colors?

• Tail: How long is the tail? What shape is it? Is there a prominent fork or any long plumes? Is the tail folded or spread in flight?

• Legs: What color are the legs and feet? Do they extend past the tail or stay tucked underneath when the bird is flying?

Even with a great view, it can still be hard to properly identify a seabird. While visual clues are the first tips to look for to identify a species, it is important to take other factors into consideration as well.

Other Ways to Identify Seabirds

When visual clues aren't enough for a confident identification, other characteristics can help confirm a seabird's identity.

• Range: While pelagic birds do wander and vagrant sightings can occur far outside expected ranges, where the bird is seen is the first clue for its identity. Note the season of the sighting, as well as how far from land the bird was seen for additional tips to puzzle out the species.

• Flying Height: Some seabirds stay very close to the surface of the water, while others have a greater tendency to soar. Note how high the bird flies as well as whether it is flying with or against the wind.

• Flight Pattern: Wing beats can be vital clues for identification. Note how quickly the bird flaps as well as how the wings are held when they are still, and watch for any rocking motion or use of the feet. Compare those behaviors to similar species to be sure of the bird's identity.

Seabird identification is one of the greatest challenges for birders, but by understanding what to look for and how to observe these mysterious birds, it is possible to become more confident and enjoy that challenge. It may not be possible to accurately identify each one, but with every trial you can learn more about the fascinating lives of pelagic birds.

Photo – Cape Petrel © Liam Quinn