I thought I should make an updated list of this as the one I found is no longer an active user.

A lot of these can be found in the Elephant Dung (the wiki page here in case you are curious).

Please let me know if anything has changed with any of these or if there are more!

All zones:
Archer's Buzzard Feather
Flamingo Feather
Shining Drongo Feather
Senegal Feather
Shoebill Feather
Kingfisher Feather
Vulturine Guinefowl Feather
Albino Feather (December only)
Nightjar Feather
Shrike Feather

Temperate Savannah:
Barn Owl Feather (Night only)
Hornbill Feather

Shrubland:
Grass Owl Feather
Ostrich Feather

Tropical Forest:
Hornbill Feather

Dry Savannah:
Secretary Bird Feather

Rocky Hills:
Pel's Fishing Owl Feather
Grey Crowned Crane Feather
Cape Eagle Owl Feather
Striped Eagle Feather (Good Karma only)
Sacred Ibis Feather
Stork Feather (two if you get the March Encounter)

Arid Desert:
Little Owl Feather
Sacred Ibis Feather

Marshlands:
Spoonbill Feather
Marsh Owl Feather (Night only)
Egyptian Goose Feather (Wet Season only)
Vulture Feather

Waterhole:
Crane Feather
Black Heron Feather (gives Evil Karma)
Long Eared Owl Feather