In the scope: the great CORMORANT

28/2/2017

The Great Cormorant Phalacrocorax carbo is perhaps not one of birdwatchers’ favourite birds. It is too common for that, as well as being perceived as rather inelegant. As a fish-eater, it is disliked in many parts of the world by those involved with commercial fisheries and has been persecuted in the past. However, current global populations are high.

The race that occurs in Hong Kong is Phalacrocorax carbo sinensis, which ranges from western Europe eastwards through central Asia to eastern Russia, India and China. It is one of the most abundant birds at Mai Po in the winter and, to my mind, the reserve would be far less atmospheric without these birds. Those that occur here are thought to breed in Mongolia or perhaps a little further to the north in Russia. Birds are usually present from the first week of October through to the second week of April with peak numbers occurring in January and February. The majority of birds depart in the second half of March.

Up to 10,000 winter in Deep Bay. (The highest count is 11,424 in February 2005; the peak count in the last winter [2015/2016] survey was 8,247 in January.) This is around 8-10% of the regional population, making this one of the most important wintering sites for Great Cormorants in Asia.

The birds may be seen as a threat to the fish in the commercial ponds around Mai Po. Some of these ponds have thin wires strung across them to deter the cormorants and this appears to be effective in reducing predation on fish by the cormorants. The majority of cormorants, however, seem to feed out in Deep Bay or offshore in other areas when large shoals of fish are discovered.

Mai Po itself is mainly used as a safe roosting and loafing site by the birds; the trees near the Education Centre are particularly favoured and slowly turn white during the winter due to the birds’ droppings. Come March, the trees look lifeless but once the cormorants depart, the leaves grow back and the trees seem none the worse for the wear.

The images that follow were taken when I was preparing Mai Po: The Seasons-A Photographic Essay.