Sparrow numbers see huge drop

The number of sparrows has dropped by 10 percent from last year to 243,000 this year, says the latest sparrow census by the Hong Kong Bird Watching Society.

The eighth annual census was conducted by over 120 surveyors in May on 88 one-kilometer routes across the city.

Surveyors estimated that about 243,000 sparrows lived in urban Hong Kong. Last year the number was 268,000.

The study also found that except for rural and commercial areas, sparrow numbers decreased in other land-use categories compared to the previous year. People in village-type areas, residential areas, and recreational areas can see sparrows more often.

In terms of districts, Sham Shui Po continues to be the area with the highest density of sparrows, closely followed by Tuen Mun and Wong Tai Sin.

Nearly 34 percent of 145 sparrows' nests are built in vents, one fifth in air-conditioners and 13 percent on vegetation.

Surveyors also carried out estimates for four common urban species - the Spotted Dove, Oriental Magpie Robin, Red-whiskered Bulbul and Red-billed Blue Magpie, of which only the number for the last one increased.

Although the number of sparrows in the past two years have stabilized after hitting a low of 210,000 in 2021 from around 300,000 sparrows in 2016, the society believes that at least 10 years of continuous monitoring are needed to accurately understand trends.

"The society hopes more enthusiastic citizens will become census surveyors, participating in and promoting citizen science research to increase awareness and understanding of urban ecology," it said.

It also hopes the public can address and eliminate various hidden crises faced by urban birds, citing glass buildings and rodent glue boards as two of the crises they face, adding 250 bird-collision incidents have occurred since 2021.

It urged property owners to assess collision risks for their buildings and implement measures, and the government to consider legislation to promote bird-friendly architecture.

People were also urged not to use to rodent glue boards as sparrows might get trapped and die on rodent glue boards after being attracted by stuck insects.