A few days ago some discarded lemon wedges were strewn on the ground near the barbeque. Early next morning I saw a male Common Blackbird pecking at a lemon wedge.
As I watched, the bird spread a wing and, using the primaries and tail feathers to brace itself, proceeded to pass a piece of the lemon flesh through its plumage.
I can only conclude it was using the citric acid in the juice to deter parasites as it might use formic acid from ants, but can find no reference to such behaviour by this species.
Interestingly, the Common Grackle, Quisculus quiscula a North American species, possibly to rid itself of parasites, allows ants to crawl on its feathers and release formic acid, but may employ lemons and limes, chokecherries, and even mothballs for the same purpose (Sibley 2013).
John K. Layton
Holt.
