Seabirds: Their Lives and Ecology

Chris Swarth saw his first puffin in 1976 on the California coast; he then had an opportunity to learn how to study them for three years in the Farallon Islands, 35 miles west of San Francisco. The Farallon Islands were settled in the 1800s. The eggs from the birds were not only harvested, but fought over. In the 1870s the Coast Guard built a lighthouse, which was manned until about 25 years ago when they were all automated. In the late 60s, sanctuaries were set up to protect the area of these islands.

Presentation

Seabirds are linked to the ocean environment; the only time they are not on the ocean is when they are nesting. Examples: albatrosses, petrels, boobies, auks frigatebirds, penguins, phalaropes, long tailed ducks, sabine’s gull, arctic tern, black-legged kittwoke.

Characteristics:
• Long-lived (20-60 years)
• Delayed sexual maturity: up to 10 years
• Small clutch size: often just 1 egg
• High degree of parental care
• Long fledgling period
• Usually monogamous; some mate for life
• 95% of species nest in colonies, some with 1000s of pairs
• Often nest on islands or cliffs safe from mammalian predators
• High degree of breeding site fidelity and philopatry
• Special adaptations to a marine life

Seabird adaptations
• Dense plumage
• Superior waterproofing
• Countershading plumage: dark above, light below
• Strong, flexible webbed feet

Another adaptation: their eggs have a shape that’s unlikely to roll off--it is very tapered on one end. Each egg has a characteristic color and pattern to help pairs recognize their eggs in crowded breeding colonies.

Dynamic soaring: Birds can soar or fly without flapping their wings. Soaring birds go in an up-and-down pattern: climb, change of flight direction to leeward, descent (leeward), climb (windward).

Convergent Evolution: Penguins and Auks exhibit convergent evolution. Though adaptation to similar ecosystems and life styles these unrelated bird families have evolved similar body plans.

Common seabirds of the Gulf of Maine
• Cormorants
• Storm-Petrels
• Shearwaters
• Diving ducks (eider) Gulls and terns (laughing hgull, herring, black backed, common tern, arctic tern, roseate tern, least tern
• Alcids

Although many fisheries are depleted, there is still a rich ecosystem to support these birds.

The currents bring the nutrients into the area; the winds that move across the ocean, that power the flights of the birds from the south are also important. Birds can read the winds and the currents and find the food.