When I first observed these birds worldwide

These are only birds I've seen or heard myself, sorted from newest to oldest observations. A total of 225 species is included, 224 of them have been observed.
There are about 11,000 species of birds in the world, so this is just the start! By country first seen that's: Switzerland 147, United States of America 37, Spain 21, Costa Rica 8, Italy 4, Portugal 3, Thailand 2, Mexico 1, Panama 1.