A flock of pacific swallows are perched on a metal structure at Singapore's Marina Bay on Oct. 28, 2020. (Photo by Then Chih Wey/Xinhua)
Two pacific swallows are perched on a metal structure at Singapore's Marina Bay on Oct. 28, 2020. (Photo by Then Chih Wey/Xinhua)
Two pacific swallows are perched on a metal structure at Singapore's Marina Bay on Oct. 28, 2020. (Photo by Then Chih Wey/Xinhua)
A flock of pacific swallows are perched on a metal structure at Singapore's Marina Bay on Oct. 28, 2020. (Photo by Then Chih Wey/Xinhua)