Behind the Te Papa museum is a pedestrian bridge with a small stream dammed up beneath it. The seagulls and ducks really like the fresh water and there is constant activity of birds bathing and drinking water.
The images did exhibit some chromatic aberration abound the birds and the cement background. initially I thought this was due to deficiencies in the Tamron PZD, but my friend took the exact same photos using the 18-55mm and 55-250mm Canon kit lenses and he had the same CA problem. Oh, well, nothing a little post processing cannot fix. The Tamron PZD gets more fun to use as days goes by, and because I do not have to swap lenses as often I end up getting more shots than if I had to rely on my kits lenses.
A quick tip, when shooting birds try and keep the shutter speed high, even if that means dropping to a faster ISO.
I've left a bit of CA around the seagull on the left for you to get an indication of the impact the bright white feathers have on the darker background.