Two Eastern Kingbirds noisily fruit-catching (hover gleaning) in my mulberry tree this evening (6 May), first of the year.
I told my two research students that the birds spent the winter in the amazon eating mainly fruit; they eat fruit even during migration; and that they are about to switch to a mainly insect diet in North America.
Incidentally, it's surprising that there seems to have been just one formal study of mulberry frugivory in N. America--that was in Michigan in 1975 (Robbins et al., Jack-Pine Warbler Vol. 53. No.4). I would have thought such a birdy spectacle would have been studied more. (In contrast, there are many studies of fig frugivory in the tropics).