Ive got a 404 on that link, but Im sure I could find one that counters it - you say it relates to observations around feeders, so maybe not ideal, but I get yer drift. A decent study could assist The 'keets are up there with the extended crow family in the omnivore approach to eats- they can process just about anything. I wouldnt go along the predation path, but their different breeding cycle, flocking instinct and pure size do impact the native stock in areas where they have flourished. Sadly, unlike much of the brit stock, they are not as likely to be prey to cats as they dont do much ground time. on an associated note/ anecdata, gardner friend witnessed grey sqrls eating a nest of new born chicks last year- hes not seen this before anyway