Huang Chee Thong a.k.a. bloodlamb documented a pair of Scarlet-backed Flowerpecker (Dicaeum cruentatum) at the Sungei Buloh Wetland Reserve eating the fruits of the common buah cherry or Indian cherry (Muntingia calabura). The bird did not swallow the fruits whole. Instead, it picked a ripe fruit in its bill and squeezed it, taking in the soft pulp packed with seeds and casting the skin. The image of the female sunbird (above left) shows the berry emptied of its contents, that of the male (above right) shows the fruit before being squeezed.
John Vickerman, our resident bird behaviourist, has this to say: “What I suspect is happening here is that the flowerpeckers have learnt that by squezzing the fruit they can gain access to the juices inside which will be sweet and sugary thus providing them with the almost instant energy feed that most very small birds need. More efficient than having to digest a whole lot of berry skin and pulp which will be discarded anyway apart from the fact that it looks as if the berries would be too big to swallow in the first place. Nature’s way of creatures learning to get at food that would normally be inaccessible.”
A few decades ago the Indian cherry tree was very common in Singapore. Birds spread it far and wide and the trees grew in wastelands, gardens, sidewalks, etc. Growth of the tree is rapid, becoming fully grown within months. Medium sized with a spreading crown, it was common to find a serabat stall below its shade, dispensing coffee, tea and ginger water. These were the stalls that made tea-tarek popular, tossing the hot drink from a glass to a large copper container and back to cool it for customers.
These trees were subsequently placed on the “hit list” of certain government agencies as the many birds attracted to the fruits soiled the ground below. Now, a few such trees are slowly being reintroduced as a bird tree. But not too many are tolerated.
This post is a cooperative effort between NaturePixels.org and BESG to bring the study of bird behaviour through photography to a wider audience.