An Atlantic Puffin feeding its chick in the nesting burrow
Alcids are the Northern Hemisphere equivalent of penguins, but they are not related. They have developed similar solutions to the challenges of finding food in a frigid ocean, an example of convergent evolution.
■ Colonies of nesting seabirds are critical to the ecology of their region in many ways. By gathering fish from the ocean and carrying them onto land, the birds concentrate nutrients and move them uphill, essentially fertilizing the area around their colony. The increased plant growth provides a home for many other species of animals. One study even found that ammonia particles released from the guano of seabird colonies in the Arctic are an important component of cloud formation there, essentially “seeding” clouds and helping to cool the region.
A seabird colony on a small rocky island
■ The large colorful bill of a puffin is a strange and wondrous thing, and has earned it nicknames like “sea parrot.” But why do puffins have it? The color is probably for show, a flashy pattern that looks good to other puffins, but the shape and size of the bill is harder to explain. Most species with large bills, such as toucans, live in hot climates, where their bill helps radiate heat out of the body. But puffins live in very cold water; how do they survive with such a large bill? In addition, a tall bill is streamlined for moving forward but not as good for moving sideways underwater. One possible advantage is that the extra height adds stiffness and keeps the bill from bending, allowing the puffin to clamp down tightly on multiple fish.
An Atlantic Puffin, from the front and the side
■ Murres, related to puffins, feed on small fish and commonly dive to six hundred feet or more below the surface of the ocean, using their wings for propulsion (unlike loons—see this page). At that depth, even on a bright sunny day in clear water, the light level is the same as midnight on the ground with just a sliver of moon. Murres also commonly forage at night, when their preferred prey move closer to the surface, but they still dive up to two hundred feet deep. It seems unlikely that they are using vision to locate and pursue their prey, but nobody knows what senses they are using. Similarly, no one knows how the birds withstand the pressure at those depths (for example, how they keep water from penetrating through their feathers), or how they can travel that far and fast without breathing.
A Thick-billed Murre diving into the darkness