September 26, 2017

Numbers holding but gulls not in good shape

Standing at the summit of the Glenorchy tip to the north of Hobart with grey clouds over the mountain threatening snow, it occurred to me there was a downside to birding.

Once upon a time it was enough to just watch birds, and revel in the beauty of their plumage and sweet melodies. Now it’s incumbent on the birder to also engage in citizen science to record bird numbers, especially of the many species decreasing in population across the country.

So on a winter’s day here I was on the Glenorchy tip, facing into a chilly wind with not enough power in it to carry the smell of rotting rubbish away from my nostrils

Species of kelp and silver gulls were having a fine old time, however, along with forest ravens.

Despite my discomfort, I wasn’t complaining. I was doing my bit, making a difference even if the subject of this project – gulls – might not be at the forefront of the fight to save birds in general.

Gulls occupy a niche in conservation science which is not only about vanishing species but also about how birds can be a pointer to the health of an environment which also embraces humans. Not only can they indicate poisons, like lead, on land and in water they can also mirror the health of the people with whom they share the habitat of city and suburbia.

Gulls tend to share the same unhealthy fast-food and, as I have written in the past, research in recent years into the health of city gulls has taught us that they are afflicted by very much the same health issues that city-dwelling humans are. Namely, they are obese from a lazy lifestyle in which they do not have to travel far for food, and as a result they have dangerous levels of cholesterol and glucose in their systems.

Perhaps more than any other group of citizen, birdwatchers are ideal candidates for citizen science because their hobby involves noting and counting bird species.  Now, instead of merely compiling lists of birds for checklists of species spotted, birdwatchers are increasingly monitoring bird populations on their home patches for a data base compiled by the national bird organisation, BirdLife Australia.

Clutching my clipboard at the Glenorchy tip, I attracted as much attention from people arriving to dump their rubbish one Sunday morning as I did from the gulls.

Out of the three species of gulls found in Tasmania kelp gulls were clearly the majority at the tip, about 300 of them flying around, and I was tasked with  separating the species into groups incorporating black-and-white adults, juveniles aged between two and four years in “salt and pepper” plumage, and first-year birds which are mainly clothed in brown. Silver gulls, were easier: there were only about 10 of these and none of the third species of gull found in Tasmania, the Pacific gull, which prefers a marine environment.

Comparing surveys over the years, BirdLife Tasmania, the local affiliate of the national ornithological organisation, reports gull numbers in Tasmania are holding their own, But that’s not to say they are in good health.

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