I emailed Drs Robert Webster and Guan Yi, re the PNAS paper. Various questions. Dr (Prof) Guan promptly sent email with some brief answers:

Re species carrying virus between Poyang and Qinghai: "As we point out in our paper, it is migratory duck." – I’ve replied, saying this isn’t detailed enough. He and his team rightly want detail re virology. But detail needed too re wild birds. Especially where no migration routes (so far as I’ve seen) known to link Poyang and Qinghai – and places Poyang birds known to migrate to did not suffer major die-offs.

Qn: What information do you have on H5N1 in poultry and wild birds elsewhere in central and northern China, especially between Poyang and Qinghai? "As far as I know, no any other groups would like working as hard as our group to do surveillance study for long-term. So, H5N1 information between Poyang and Qinghai is not clear. If you can provide some information to fill the gap, it would be very useful." – well, wish I could supply or find such info. But with a vacuum of data for north China, saying there is certainly a direct link between Poyang and Qinghai is surely impossible (well, not if good science anyway).

Qn: Did you consider transport within the poultry trade, even smuggling – perhaps of those apparently healthy chickens? "There is no limitation for poultry movement, but it would not make any sense if poultry were transported that far away." – directly from Poyang to Qinghai would indeed seem silly. But transportation networks in n China? Remembering, too, an outbreak at goose farm in nw Xinjiang. Point: A previous outbreak in poultry in Tibet was traced to a source in Lanzhou – not a great distance from Qinghai, so trade/smuggling would seem plausible. "Do you have convince data to prove this link? How closely related between the virus from Tibet and Lanzhou? Please think question in molecular virology point of view as well." – sent the info, which from an FAO report; nothing on virology tho.

Qn: I’m curious: why were you able to obtain so many specimens from birds at Poyang? "I have big group in mainland working for me."

Qn: Further, were there indications of H5N1 killing wild birds at Poyang? "Some of them, Yes. Died birds were observed during some seasons." [would be good if had info on poultry farming around and fish farming at Poyang. inc whether any domestic duck farms – this is the kind of place where wild birds might mingle with domestic] Nothing yet to my follow-up email.

Nothing, too, from Robert Webster (inc no answer to whether he is fully objective!) [third time, I think, I’ve tried emailing Robert W; wonder if should really be hopeful] Article on Webster, inc re his belief birds are pivotal with flu, and dangerous pandemic may loom: Profile: Robert Webster

"Perhaps his most valued contribution is the idea that wild birds are a reservoir of influenza viruses" – now, seemingly aiming to show wild birds can also carry dangerous Poultry Flu. And not too fussed about fiddly things like details re wild bird species, migration routes and timings.