Creature Feature: Pelagic Cormorant
A pelagic cormorant surfaces with water still on its back. Image by Becky Matsubara Flickr Creative Commons
Pelagic cormorants (Phalacrocorax pelagicus) are common sights in the Salish Sea. It is pretty special that such amazing birds call it home. Now you may think, I see cormorants all the time, what could be cool about them? For starters, they they dive over 130 feet for their food and glue their nests to cliffs with their own poo. Can you do that? (The diving part…) It just gets better from there. Dive in and explore a cormorant’s world!
Chow time
What are cormorants after on such deep dives? Fish! These divers are perfectly adapted to catch fish with long, hooked beaks that help them to snag prey on the fly… er, on the swim. They can stay underwater for over two whole minutes as they hunt. They also will pluck small invertebrates from rocky reefs. Small fish are their main food group, but they also chow down on crustaceans (like crabs), snails, worms, and other invertebrates.
Close company
Pelagic cormorants covering a wall (with more than just their bodies, look at all that guano!). Photo by Ingrid Taylor, Flickr Creative Commons.
Don’t be fooled by their name - pelagic cormorants actually spend more time closer to shore than they do in the open ocean. These cormorants breed and nest on shorelines and rocky cliffs or even ferry terminal wingwalls. They select inaccessible spots with deep water below. Yes, their nests are glued with poo, cementing seaweed, dry mosses, marine debris (yes, plastics), grass, and sticks into a safe haven for eggs and chicks. Home sweet home, if you consider the aroma of festering, fishy feces sweet, that is.
Nesting up high on cliffs helps them to avoid predators. They also nest in colonies, which means that many other nests with other cormorants will be nearby. Safety in numbers! Sometimes, if you walk or boat past a colony of pelagic cormorants, they will croak and growl at you. Although they seem to be social, they actually keep to themselves. In fact, when they hunt for fish, they are usually by themselves.
Plumage change
Both males and females are black with an iridescent green and purple sheen throughout the year. In spring they grow fancy, white feathers on their thighs to show they are ready for summer breeding. If you spot these white rump patches during flight or peeking at you while roosting, you’ll know it’s a pelagic cormorant and not one of two others in the Salish Sea. The others are double crested (as in the one in the photo eating the catfish) and Brandt’s cormorants (with the turquoise throat in the photo below).
Pelagic cormorant hanging its wet wings out to dry. Image by Rick Derevan, Flickr Creative Commons
Master divers
Like we mentioned, pelagic cormorants can dive really deep and all in under two minutes. How do they sink so fast? One thing is they have heavier bones than most birds, which helps. Also, unlike most water birds, cormorants do not have much oil to secrete and rub around their feathers. Oil helps waterproof feathers and trap in air, but getting a little waterlogged forces those buoyant air bubbles out and keeps cormorants from bobbing back to the surface. Because of this, they actually stay quite soggy after they swim. You can tell if you’ve ever watched one try to take off as soon as they surface. They first have to run on the water to achieve lift-off. The solution? Hang out to dry! Perhaps you have seen them hanging around on pilings or powerlines with their wings held up, like a load of laundry hung to dry.
Oh baby !
A Brandt’s cormorant, the smallest of the Salish Sea cormorants, with its distinctive, turquoise throat (gulag pouch). What do you suppose this one is telling that gull with its body language? Image by Roy W. Lowe US Fish & Wildlife Service
Around April through June, Pelagic cormorants lay 3-4 eggs in a nest and incubate them for about one month. Both the male and female take turns incubating the eggs while the other goes to feed. When the young hatch, both parents also stick around to tend to the young and feed them. If you see a young cormorant pecking its parent’s beak and throat while squawking obnoxiously, they are hoping to trigger mom or dad to regurgitate their latest catch. You may even see the chick’s whole head disappear into its parent’s throat as it dives in to suck down the fish slurpy! Juveniles take flight in about seven weeks and start fishing for themselves. What could you do at seven weeks old?
What can we do?
Who are Pelagic cormorants afraid of? Unfortunately, humans have historically been their greatest threats. Humans have been responsible for trying to eradicate pelagic cormorants, because they think that they are competition for fish industries. Cormorants are actually hunting species of fish that are not typically used commercially, like sand lance, gunnels, greenlings, sculpins, and more, but fish we like to catch, like salmon, do depend on some of these smaller fish. Some consider cleaning up our waterways and restoring salmon habitat a better option than killing their predators and competitors. When you remove part of a food web, it is hard to see all the ways that could harm other wildlife.
Other ways humans cause harm is accidental. Cormorants get entangled in lost, floating nets, mistake plastic waste for food, and get coated and poisoned in oil spills. It’s important to remember, however, that people can do magnificent things for wildlife! By reducing our use of plastic, packing up and safely disposing of trash and nets, fixing oil leaks in our cars, driving less, and protecting the habitats that fish and the cormorants live in, we can do a lot to help these birds live safe, healthy lives.