Since the question of looking for DNA evidence of Ivory-bill presence keeps popping up I asked Cornell directly what if anything was going on in that regard. Here's the pertinent part of the response I received, for those interested:
"... It is possible to make a positive ID by using DNA markers and we have been doing this, pulling feathers from scalings and testing them for DNA. In all cases, the feathers were from Pileated Woodpeckers. Extracting DNA in any other way, like saliva or foot prints, as you suspect, would not be possible.
One thing that has been discussed is to use a DNA vac to pull up material from the floor of a cavity. However, in order for this to be a reasonable thing to do, we'd have to have identified cavities that were quite likely otherwise this would not be in the least cost efficient."
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