Expand the Library for '3+3+4'
Preserve the Beacon for Posterity

Legless Birds at CUHK

In a famous line from the movie Days of Being Wild, Yuddy (Leslie Cheung) compares himself to 'a legless bird' that must keep flying and flying, because the day it lands is the day it will die. In reality such creatures do exist and many are residents of CUHK. They are the house swifts.

In the scientific name of the house swift Apus nipalensis, the Latin root apus means 'without feet'. They are thus named because their short legs and hook-like feet are only good for clinging to vertical surfaces. So, unlike other birds, house swifts never land on the ground because they cannot take off again if they do.

The University Library is home to the largest swift colony in Hong Kong. It is estimated that at least 200 house swifts have built their nests there, accounting for 20 to 30 per cent of their entire population in the city. To better protect them, the University has commissioned a 17-month study on them from June 2007 to October 2008 and ongoing monthly monitoring.

Dr. Tsim Siu-tai, external consultant of the study, says, 'Its coarse surface, high and hidden eaves, and abundant supply of nesting materials and food by the natural surroundings make the University Library an ideal nesting site for house swifts, attracting a large group of them to build their homes there.'

There are about 150 to 220 nests at the University Library, mainly distributed along the eastern and southern walls. Dr. Tsim has proposed a number of mitigation measures to the University to deal with potential disturbances to these nests, including sealing off affected eaves at the northern walls of the library before the breeding season of the birds, which starts in May, to urge the birds to move elsewhere. Nest boxes should also be installed at nearby potential nesting sites. Having studied the flight paths of the house swifts, Dr. Tsim suggested that an adequate buffer area be set up in the vicinity of the University Library to ensure clear airways for the birds to fly in and out of their nests when construction works are taking place nearby.

'Feeding on flying insects, house swifts are top consumers of the food chain and play an important role in maintaining the ecological equilibrium of the CUHK campus,' says Dr. Tsim. The University has committed itself to protecting these avian residents of our campus. When asked what CUHK members can do to promote the wellbeing of our feathered friends, Dr. Tsim has a piece of advice, 'The simplest thing we can do is to tolerate the little inconvenience caused by their droppings.' However, we should also be cautious about the possible impact of avian flu.