NOTE: we are not here to self diagnosis your bird (s) this is an information article only and we always suggest seeing an avian vet for diagnosis and treatment.
Contributed by Liv
About 2 weeks ago during random checks of my birds, I discovered tiny feather mites on the flight feathers of most of my aviary birds 
They look like tiny bits of dirt in the feather (a flight feather tip from one of my birds)
Zoomed they look like this (not my photo)
It is unknown when the mites got introduced to my flock, but it was sometime during autumn as my inside birds (who came inside in autumn) are clean from the mites.
A little bit about the feather mite
Feather Mites: These tiny arachnids are so extremely small that to the naked eye they appear to be tiny dirt particles on the bird's body, wing, and tail feathers. On the Purple Martin, "colonies" of them can be seen on the long wing and tail feathers between the feather barbs, but you'll have to have the bird in your hand to see them.
These tiny (0.5 mm long) feather mites get their nourishment by chewing on the feathers. Although these parasites are typically harmless, they can severely damage an individual's plumage during heavy infestations.
Other species of feather mites, known as quill mites, pass their entire life cycle within the hollow confines of the wing feather quills. These types feed on host tissue fluids by piercing the quill wall with their sharp mouth parts.
Treatment
AVIAN INSECT LIQUIDATOR
A.I.L. is an effective water based insecticide and insect growth regulator that gives three way protection for all avian species.
3 Way Protection. When used directly on the bird, A.I.L. penetrates deep into feathers to kill lice and mites. When sprayed around the environment A.I.L. kills insects on contact and the residual action guards against re-infestation for up to six weeks. Also, the growth regulation effect of A.I.L. prevents insect eggs from hatching and newly hatched insects from reaching maturity.
Directions
Use a 5% solution (1 part concentrate: 19 parts water – 20 parts total) NOT FOR USE WITH REPTILES OR FISH. Hold trigger pack 30-40 cm from bird/s and spray directly on to birds/s. use 4-5 pumps per bird. Cages, aviaries, perches and nest boxes should also be sprayed thoroughly with the diluted product. Repeat in 6 weeks or as necessary.
Guaranteed Analysis
Permethrin 25g/L
Piperonyl Butoxide 125g/L
Methoprene 0.4g/L
I found AIL too hard to get here in SA so i used Coopex to treat my birds which contains the same amount of Permethrin as AIL when a 25g sachet is made into a 10L solution. I treated all my aviary birds, cleaned out the entire aviary and treated all the perches and surfaces - it was very comforting to see happy birds and dead bugs everywhere
Next time you are looking at your birds, check for little speaks of "dirt" in the flight feathers - you may need to treat for feather mites too.
