The bird in the image below has me somewhat confounded.
It’s clearly a tern, but which species?
I spotted it late yesterday afternoon on the Moolort Plains. As I quietly watched a distant feeding Brolga, it must have passed directly over my head, observed briefly in fading light as it headed north.
Whiskered Terns are the most commonly observed birds from this sub-family (related to the gulls) and can be seen in wet years on freshwater wetlands and regularly on Cairn Curran, along with the much larger Caspian Terns.
It was a fleeting glimpse but this individual looked intriguingly like a Gull-billed Tern Gelochelidon nilotica, a reasonably common species in northern and southern Victoria, but one that I’ve never observed locally. The overall appearance was of a bulkier bird than a Whiskered Tern, with less buoyant flight. Adult breeding Whiskered Terns have a black cap and nape, as do Gull-billed Terns, but have a red bill, not black and their underparts typically are sooty. The upper parts of the Gull-billed tern are almost white, rather than grey. Another clear difference is the bill shape – slender, with a less pronounced ‘gull’ conformation than the G.nilotica.
I’ll put this observation in the maybe category for now and would be interested in any reader thoughts. Sadly, the image below is the best one I have!
Postscript: The view from a number of expert birders is that the tern is in fact a Gull-billed Tern, a rare visitor to central Victoria. One was reported at Lake Eppalock (near Bendigo) on the 9th September.