This is a field Mystery Cache centred around Mayflower MRT Station (TE6) on the Thomson-East Coast Line. The published coordinates will bring you to one of the station exits where you will need to use the information in the listing to solve the puzzle and find the keyword, which will unlock the final coordinates in Certitude.
You may recall the classic nursery rhyme "Sing a Song of Sixpence", which features "four and twenty blackbirds / Baked in a pie" and we are then told that "when the pie was opened / The birds began to sing". While you won't be encountering live animals baked into pastries in this station (thank goodness!), you'll instead find plenty of birds flitting about, and... in fact, there are approximately "four and twenty", according to my rough count. These birds are songbirds, drawn from the local tradition of keeping and displaying these beautiful creatures who have quite the vocal range and talent, a practice that lives on in the Kebun Baru - Mayflower area to this day.
However, many of these birds are imported species, and have been dwindling in number in the wild as a result of poaching for the songbird trade. In fact, many species have become illegal to traffic and sell in recent years, and so, let us instead enjoy the beauty of these birds in the wild... or at Mayflower MRT station. And now... about the cache.
The Puzzle
Your task here is simple - seek out the birds, and solve the puzzle below:
You won't need to enter beyond the fare gates to find them all. Once you have solved the puzzle, figure out the keyword and plug them in Certitude below to gain access to your final prize (which is not a bird).
Good luck and I hope you'll enjoy the urban birdwatching!