Double-crested Cormorant

                                            Double-crested Cormorants in Breeding Plumage

The Double-crested Cormorants have been returning to the province for the last week or so.  I saw a flock of 125 floating as a raft down the St. John River at Crock's Point last weekend (April 16) and there was a report of about 400 roosting on the piers of the former Fredericton bridge that same weekend.  They were  migrating up the St. John River in large numbers.

The Double-crested Cormorant (Nannopterum auritum) was classified as the Phalacrocorax genus until 2021 when the genus was changed to  Nannopterum by the IOC.  The genus name, Nannopterum, means small winged which came from a flightless member of the family.  The auritum means 'eared' which comes from the nuptial crests.

Cormorants are long-necked diving birds of which there are 6 species in North America.  In New Brunswick we have 2 species, the Double-crested Cormorant and the Great Cormorant.  For more information on the Great Cormorant, search this blog.  Cormorants in general have long necks, long, heavy bodies, stiff tails and long, hooked bills.  The Double-crested Cormorants are large birds, 70-90 cm long (28-35 inches).   They feed mainly on fish but also amphibians and crustaceans which the catch underwater by swimming  swiftly with the strong propulsion of their feet.  They get their feathers wet while swimming in order to reduce their buoyancy.  After a feeding session they perch and dry their wings by perching and spreading them out.  That is a characteristic cormorant sight.  See the photo below. 

                                    Double-crested Cormorant Juvenile Drying its Wings

The Double-crested Cormorant in breeding plumage is all black with greenish or greyish patterning on its upperparts.  Its bill is yellow or orange and its gular (throat) patch is orange.  It has bare supraloral skin (in front of the eyes) which is orange.  In breeding plumage the bill is blackish above and pale below.  Males and females look the same and juveniles are a duller gray-brown.  The alternate plumage (non-breeding) is similar to the breeding plumage but duller.  

So what about the crests?  In breeding plumage they sometimes show a pair of tiny crests/plumes on the top of the head which can be black, white or peppered.  The white crests/plumes are more often seen in the north and west of their range.  

The Double-crested Cormorant likes both salt and fresh water unlike the Great Cormorant which also occurs here.  In order to tell the two species apart you have to take a close look to check for the larger size of the Great Cormorant and its white chin patch and white flank patch.

The range of the Double-crested Cormorant covers most of North America except the far north.  They breed in most of southern Canada and the US including all of the Atlantic provinces.  A few are beginning to remain here for most of the winter along our coasts.  They winter on the west coast from Alaska to the Baja Peninsula and in the east from southern Maine to the Yucatan Peninsula.

                                                    Double-crested Cormorant Juvenile 

During the breeding season the male has an elaborate courtship dance in which he presents the female with nesting materials and points out a suitable nesting site.  The nest is built of twigs and seaweed and in it the female lays two pale blue eggs.  Both adults incubate the eggs for 28 to 30 days.  

The vocals of this species are not spectacular to humans.  Their deep guttural grunts are part of the aquatic landscape.  Because they are gregarious birds and often found in colonies, they can be loud.

Today the population size of the Double-crested Cormorant is healthy and increasing.  In the 1960s their numbers decreased due to DDT poisoning.  Because they are perceived as being detrimental to the fish stocks, there has been some loss by humans destroying them.  In recent years their population has increased probably due to less contaminants in the water and the rise of the aquaculture industry.  They have increased in the Great Lakes region due to the rise in the non-native species of fish, the alewife.  In some places culling operations have taken place to control the Double-crested Cormorant population.  

In the wild the Double-crested Cormorant life expectancy is 6 years.  The oldest documented wild Double-crested Cormorant lived to be at least 17 years 9 months.

                             Double-crested Cormorant  Showing The Turquoise Eyes  [Internet Photo] 

Black Guillemot - A Local Marine Bird

                                                Black Guillemot in Breeding Plumage

The Black Guillemot (Cepphus grylle) is a small marine bird species which is a resident of New Brunswick.  It is a member of the Alcidae family.  It is found commonly at the mouth of the Bay of Fundy and breeds on many islands there.  It is also common along the shores of the Acadian Peninsula in fall and winter and it breeds at Heron Island, Belldune, and Pokeshaw in Chaleur Bay.  Like all alcids, Black Guillemots are rarely seen on fresh water and come to land only when nesting.  

The Black Guillemot range is widespread in Canada.  It is found along ocean shorelines from Maine (USA) northward along the coast year round all the way to Ungava and Baffin Island.  It is also found in summer on the high Arctic islands.  It is also found on the northern coasts of Yukon and Alaska.  This species' range is not restricted to North America.  It is also found in Europe along shorelines of Greenland, Iceland, the United Kingdom, Scandinavia and Siberia.  It is, however, more abundant on the American side of the Atlantic and Arctic Oceans.

                                                Black Guillemot in Winter    [Denise Albert Photo]

The Black Guillemot is a small alcid, measuring 30-32 cm long (13").  In breeding plumage it is all black with large white dorsal wing patches.  It has bright red feet, a dark, pointed bill and bright red mouth linings.  It flies in a rapid straight line with whirring wingbeats and the conspicuous white wing patches flashing. That makes it easy to identify.  In the alternate plumage it becomes mostly white with black mottling mainly on the back.  The white dorsal wing coverts (patches) are still visible in this plumage.  Both genders are similar.  The young are similar to winter adults but are speckled all over.  

There is another guillemot which the North American birder needs to be aware of, the Pigeon Guillemot (Cepphus columba).  The two guillemot species are very similar but can be distinguished by the wing linings and the wing patches.  The Black Guillemot has clean white wing linings and a completely white wing patch.  The Pigeon Guillemot has dark wing linings and the white wing patch has a black bar extending into its base.  The Pigeon Guillemot's range is along the west coast of North America from Alaska to California so we are not likely to see it here.

Black Guillemots are very vocal especially around their breeding sites.  Their voice is a high-pitched scream or whistle.  It is described as a persistent 'peeeeeeech'.   After hatching the young utter cheeping and whistling calls.  They are noisy birds!  The red mouth linings and persistent cries must be used as signals between mated pairs.

Guillemots breed on rocky shores and build their nests under or behind large rocks.  The nest is made of debris and small stones.  One to two white boldly blotched eggs (sometimes tinted blue-green) are laid and incubated from 23 to 39 days by both parents.  The species is not colonial but a few pairs can be found nesting closely in suitable habitat.  They often nest in single pairs.  Black Guillemots are the only auk that lays more than one egg.  Guillemots feed by diving to the bottom using their wings in a flying motion under water.  Their feet are used only for steering.  They are known to dive at least 50 metres.  They feed on polychaetes, mollusks, jellyfish, crustaceans, barnacles and fish.  That is a large variety!  Each pair sticks to their own special area of water.

                                            Black Guillemot in Alternate Plumage

Black Guillemots are sometimes called 'Sea Pigeons'.  Looking at the bird you can easily tell why.  They remind one of pigeons in shape and movement.  They are also sometimes called 'Tysties'.  The genus name, Cepphus, is derived from the ancient Greek word, kepphos, which was a pale waterbird mentioned by ancient Greek authors including Aristotle.    The species name, grylle, was a local name for this species in Gotland in the 1700s.  Our English word, guillemot, is from the French word, guillemot, which was probably derived from 'Guillaume', their word for 'William'.  However it was named, this alcid is a common, enjoyable oceanic bird of Canada and New Brunswick and a delight for birders to see.  Its population numbers are doing well for now.  We hope that remains so.