An Elegant Tern (Sterna elegans)
on South Beach, Chatham, Massachusetts - 15 & 17 August 2002
This bird was originally reported and described as an unidentified orange-billed tern by Geoff Wood on 6 August 2002. Blair Nikula rediscovered it late in the day on 15 August and took a series of digiscoped images of the bird, but was also uncertain of its identity. Although Elegant Tern was considered a strong possibility at this point, the rump color had not been seen, the bill seemed a bit stocky, and in the images taken on the 15th, the mantle appeared rather dark (similar in shade to the adjacent Common Terns). Fortunately, the bird was present again for an extended period on the morning of 17 August and was studied at length from close range by many observers. Numerous additional digital still and video images were obtained at this time. The rump proved to be pure white, the mantle was distinctly paler than on Common Tern (though darker than Roseate), and the bill was determined to be well within the range of Elegant. It was also determined to be a first year bird.
The images below include digiscoped images taken by Blair Nikula on 15 August, and several others taken by Blair Nikula and Jeremiah Trimble on 17 August. These were digiscoped with Nikon Coolpix 995 cameras handheld to either a Leica Televid scope w/20-60X eyepiece or a Kowa TSN4 scope w/20-60X eyepiece. Some have been cropped and sharpened a bit. There is also an image taken by Jeremiah Trimble of a series of tern specimens from the MCZ collection.
These first six images were all taken on 17 August by Jeremiah
Trimble (© 2002) and show well a variety of features including overall shape of
the bird, bill structure and color, head pattern, mantle, carpal bar, tertial
pattern, and primary pattern.
These two images were taken by on 17 August by Blair Nikula (©
2002); the second image shows some detail on the underside of the tail and on
the outstretched primaries.
These four images were taken late in the day on 15 August by
Blair Nikula (© 2002).
This final image is of five species of terns from the MCZ
collection, illustrating relative sizes and mantle coloration. From left to
right are two Royal Terns (Sterna maxima), two Elegant Terns (Sterna
elegans), two Lesser Crested Terns (Sterna bengalensis - two races),
a single Sandwich Tern (Sterna sandvicencis), and two Common Terns (Sterna