The day after I visited Crufts back in March (yes, it's taken me two months to get round to processing the pictures!) we went for a family outing to Bristol Zoo. It was the first decent spring-like day of the year, and the Zoo was absolutely heaving with people. It's not an ideal place for photography anyway as many of the animals are behind very dirty glass (as with the lizard) or in cages of fine wire mesh (as with the red panda).
I wanted to test a new acquisition (a Fuji 1.4x teleconverter, matched to my 50-140/2.8 lens), and the Zoo was an ideal place for this. I have to say that I'm really rather impressed: there is a very slight loss of sharpness when viewed at 100%, but this is absolutely minimal. It's perfectly possible to use the combination wide open, and the converter extends the focal length to a very useful 200mm (300mm in full frame terms). An excellent addition to the kit bag, in other words.
OK, so the black headed gull wasn't exactly an exhibit at the Zoo, but it proved an ideal subject to test the sharpness and contrast of the lens/extended combination!