[NHCOLL-L:1520] Unknown flakes from mounted birds

[lgc1]

What could small brown flakes coming from mounted birds be. I looked under a 
scope to see if it was insect frass, but it did not appear to be so. It looks 
more like tiny brown relatively flat flakes. It appears to be coming from the 
birds, because I find it on the the bases they are mounted on and on every 
shelf 
of an inclosed specimen case.

Thank you for any help, La

Larkin Chases
Museum Assistant
HSU Natural History Museum