Macabre East End Entertainment (9th June 2012).

A brief visit to Three Mills Green a stones throw from the Olympic Park in East London turned up not only a few good birds but also showed me some surprising behaviour!

Just up from the Mill, on a low tide, I was watching a Grey Heron happily feeding when a flash of blue caught my eye as a Kingfisher shot through and landed briefly on the vegetation covering the river wall. It didn't stay for long before heading back along the river out of view. A Grey Wagtail was also feeding happily on the foreshore and Sand Martins were using the holes in the walls as convenient nest holes.

Nearby, a pair of Lesser Black-backed Gulls were feeding on the fairly fresh remains of one of the local Feral Pigeons. They sucessfully saw off a couple of Herring Gulls that were trying to get in on the act, but lost out to a Great Black-backed Gull. What happend next was something that I personally had not seen before - from under the mill an adult Mute Swan appeared, it headed straight for the gulls which were by now mid river with their booty, saw off the gulls and then proceeded to tuck in to the pigeon pulling off pieces of meat loosened by the gulls which it then went on to eat. As I said, a Mute Swan eating carrion is something that I had not seen previously but this one certainly seemed like it has done it before!

A slightly dirty Lesser Black-backed Gull waiting for its turn to feed. 

One of the Herring Gulls that showed an interest. 

Great Black-backed Gull with the remains. 

Mute Swan after taking the remains off the gulls.

(Although it can't be seen, the swan has the pigeon just below the water)

Although Mute Swans typically feed on plant material, they can be oppotunistic feeders and will take other food if it is available. Recorded food mentioned in Birds of the Western Palearctic (which is still the 'standard text' for birds in Europe, north Africa, and the Middle East) include fish and raw meat.