Thank you Park for this cover from South Korea. Five bird stamps are used. From left to right:
Japanese White-eye (Zosterops japonicus): The stamp was issued in 1997. It is native in East Asia but it can be found in other countries as a pet. It was also introduced to Hawaii. It feeds on insects and nectar.
Great Tit (Parus major): The stamp was released in 2006. It can be found in woodlands in the Middle East, Europe, parts of North Africa and Northern and Central Asia. It has 14 subspecies. It eats berries, seeds, spiders, insects and caterpillars.
Yellow-billed or Chinese Grosbeak (Eophona migratoria): The stamp was issued in 2002. This species of finch lives in temperate forests in Russia and Asia. It has two subspecies.
Little Tern (Sterna albifrons): The stamp was released in 1994. This seabird can be found in the tropical and temperate coasts and inland waterways of Asia and Europe. In the winter it migrates to the tropical and subtropical oceans so then it can be found even in Australia and South Africa. There are three subspecies. It feeds on fish.
Scops Owl (Otus scops): The stamp was released in 1993. I have presented this species in the past.

This is my only cover from Maldive Islands. From left to right:
Asian Koel (Eudynamys scolopaceus): The stamp was released in 2002. It lives in South and Southeast Asia. It has five subspecies. It feeds mainly on fruit but it can also eat insects, eggs, small vertebrates and caterpillars.
Swinhoe's or Forest or Chinese Snipe (Gallinago megala): The stamp was released in 2002. It can be found in southern and central Siberia and Mongolia. In the winter it migrates to South-east Asia. It feeds on insects, earthworms and mollusks.
Osprey (Pandion haliaetus): The stamp was released in 2002. I have written before about this species.
Sooty Tern (Onychoprion fuscatus): The stamp was released in 2007. This migratory seabird has nine subspecies.

This great cover from Indonesia has only one bird stamp issued in 2008.
Twelve-wired Bird-of-paradise (Seleucidis melanoleucus): This least concern South American bird of paradise can be found in lowland forests. It feeds on arthropods and fruit.

For today I chose this cover from Argentina, thank you Viviana! Four bird stamps were used. The first two were released in 1976 and the last two in 1972. From left to right:
Golden-collared Macaw (Primolius auricollis): This small macaw is native to Central America mainly in lowlands. It feeds on seeds, flower buds and fruit. It is one of the few lucky parrot species to be classified as least concern.
Plush-crested Jay (Cyanocorax chrysops): It can be found in Central-southern South America. It is also classified as least concern.
Saffron Finch (Sicalis flaveola): This South American bird eats mostly seeds. It can be found as a pet.
Rufous-bellied Thrush (Turdus rufiventris): It can be found in South America and since 2002 it is Brazil's national bird. It's of least concern and it feeds on arthropods and seeds.

Thank you Terence for yet another great cover. The whole 2010 Kent Ridge Park Heritage Trail set of four was used and canceled with roller datestamp. It was also dissent to Sri Lanka. Unfortunately the postmark applied by Sri Lanka Post is not very clear in the scan.
Straw-headed Bulbul (Pycnonotus zeylanicus): This vulnerable songbird can be found in Singapore, Brunei, Thailand, Burma, Malaysia and Indonesia. It can be found in low trees and shrubs along the banks of rivers and streams, within forest, plantations, gardens, scrubs, reedbeds and mangroves. It feeds on berries, fruits and small invertebrates.
White-bellied Sea Eagle (Haliaeetus leucogaster): I wrote about it in previous post.

Thank you Yumi for this great cover from Japan. Two bird stamps were used for postage. The Common Kingfisher one was issued in 2010 while the Red-crown Crane was issued in 1974 as a part of a set on Japanese folk tales.
Red-crown Crane (Grus japonensis): It is the second rarest crane in the world. It can be found in Siberia and northeastern Mongolia. In the winter it migrates to east Asia. It feeds on aquatic invertebrates, small amphibians, insects and plans which grow in swamps and marshes. It is an endangered species.