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Caspian Terns

Caspian Terns roost, breed and feed around the Kaipara Harbour. These gregarious, large white terns with black cap and bright red beak, are the largest of our terns, measuring an average of 51cm and weighing about 700 gm.

They are often seen flying five to ten metres above the sea, head down watching  for the small surface swimming fish that they feed on, such as yellow-eyed mullet and piper.  Once a fish is spotted, the Caspian will stall its flight and dive steeply, plunging into the sea in pursuit of its prey.

Taranui or Sterna caspia, have been recorded in the Kaipara Harbour since the first surveys of the harbour by bird enthusiasts from the Auckland branch of the Ornithological Society started in the early 1970s.

Caspian Terns are found around the world’s coastlines and off most continents except South America.  They were first recorded in New Zealand in the 1860s, but were not common until the 1970s. They now have a conservation status as protected rare native birds, and are classified as nationally vulnerable.

Human disturbance, from activities such as four-wheel drive vehicles in dune areas, and the planting of pine trees and marram on sand spits, has reduced the population nationally.

Colonies of Caspian Terns are often found at various sites around the harbour including Papakanui Spit on South Head, Rat Island off Shelley Beach, and at Manu Kapua on the tip of the Okahukura Peninsula near Tapora.


 

They prefer to breed and roost on isolated sandspits or shellbanks, and numbers at these sites vary from year to year.  Some years the sites may not be used at all by breeding colonies.

Caspian Terns usually nest in colonies of up to 300 birds and lay two or three, brown speckled, stone-coloured eggs in a shallow scrape.  In the southern Kaipara, the population has averaged around 120 birds from year to year.  As well as the main sites, they are found in smaller numbers right around the coastal margins of the harbour, often as singles, pairs or family groups.

Learn more about birding in your area with OSNZ by going to www.osnz.org.nz website and selecting the Auckland Region contact.  

Photos (Top and above): Suzi Phillips