By courtesy of Henry Lui
Wagtails are characterized by their constantly wagging long tails.
The white wagtail is a medium-sized bird in the family, with a
body length of about 19 cm. It has a gray upperpart, a black cap
and bib, and a white lowerpart. Its wings are dark with white
patches. A subspecies streaked-eye wagtail has a distinctive black
eye line. White wagtails breed in Europe, Asia and North Africa.
Their preferred habitat includes open country and area adjacent
to towns and villages. The birds are common on campus. They like
walking about swiftly and busily, and fly away only when you get
too close. They move dramatically up and down like waves when
The Birds of Hong Kong and South China (Chinese edition) , Clive
Viney, Karen Philips and Lam Chiu Ying, Hong Kong Government Information