Black Tern

Black Tern - A 'Locally' Common Tern 

Black Tern

 The Black Tern (Chlidonias niger) is described as 'locally common' in New Brunswick.  It is a species of North America and western Asia.  In North America its breeding range is from North West Territories  and eastern British Columbia eastward to New Brunswick and southward to most of the northern US states.  It winters from Surinam to Peru and Chile.  Its preferred habitats are lakes, ponds, marshes and coastal areas.  It prefers fresh water.  In New Brunswick I have seen this species at Black Duck Marsh, Lower Jemseg and near Hoyt.  It has also been seen at Grand Point, Grand Lake and Kouchibouguac.   It is rarely seen in the northern part of the province.

Black Tern on nest

Seen above is a Black Tern on its nest.  This was taken at Point Pelee National Park where there is a Black Tern colony.  The nests were on floating vegetation in black muck and among the coarse roots and debris.  The nests were almost invisible when the birds were not sitting.  They were sitting on 3 or 4 large buff eggs with dark blotches.  They were either so dark they were difficult to see or they were smeared with the black muck.  Incubation lasts 17 to 22 days and is carried out by both adults.  The whole colony seemed to be in a continuous uproar as the adults flew around screaming at one another or at bystanders.  At one point I was dive-bombed by an upset adult even though I was well back.  I did not see any chicks but was lucky to be shown a photo of one taken by another naturalist.  It was very cute with long light gray fluff and dark eyes.

Black Tern

On the sitting Black Tern shown above note the crossed wing feathers.  The Black Tern has very long pointed wings enabling it for long flight.  It is a small tern (25 cm/9.7"long) with a black head and underparts.  The back, wings and tail are light gray.  The vent (area under the tail) is white.  The bill, legs and eyes are black.  The legs are actually dark red but appear black.  They lose this beautiful plumage in winter and turn much lighter to a dark gray back and white underneath. Some patchy black usually remains on the head.  What I found interesting was the fine white line over the wings in the sitting breeding-plumaged adult as shown in the top photo.  The white on the head in that same photo indicates a young bird and is a holdover from juvenile plumage.  The head is usually all black.

Black Tern

The Black Tern has an interesting courtship ritual.  It involves much flying with the male flying around with a fish in its mouth attempting to attract a female.  It must be a noisy colony at that time!  The female who is enticed follows him to a perch where he feeds her the delicacy.  The Black Tern feeds on mainly fish but also insects, molluscs and crayfish.  They often catch their prey from the air and rarely dive-bomb like other terns.  They will swoop down to the water while flying to drink or catch prey.  They vocalize a lot and the sound is a high-pitched grating sound.

Black Terns sometimes associate with other terns.  The colony we visited had a Forster's Tern present.  Black Terns are very social birds.  They usually breed, roost and migrate in flocks.  These flocks can sometimes get as large as tens of thousands.  Black Terns spend the winter at sea.  The only similar species found here but very rarely is the White-winged Tern which is a rare visitor from Eurasia.

Black Tern