On Dec. 22, Vincent Chew posted the following video on Facebook:

In case you can't see the post, Chew took a video of a huge flock of birds flying above him in Choa Chu Kang.

For the uninitiated, a murmuration is when a large group of birds fly together in the same pattern and direction.

The post has since garnered more than 1,500 shares.

Occurred in other locations

This pattern was also observed in other locations in Singapore.

Kit Boey, a member of Facebook community Bird Sightings, spotted a similar flock of birds in Changi:

While Facebook user Zhuo Tong Qian shared this photo of birds that she spotted in Punggol.

Unfamiliar sight

Naturally, many Singaporeans were curious as this isn't something one would see daily.

Some were even scared by the jawdropping sight of the birds:

Migratory birds

But this rare phenomenon may actually be less insidious than it seems.

Nature enthusiasts from Nature Society (Singapore) and Bird Sightings have identified the species to be the Asian openbill.

Openbills are migratory birds that typically move between South Asian countries like Bangladesh and India to Southeast Asian countries like Thailand and Myanmar.

Hundreds of them were spotted in Singapore earlier this month in the Kranji Marshes.

Cool.

Top image screenshot from Vincent Chew and Sharp Photography