The banana plant and its complement of fauna

On January 2013 Tan Teo Seng gave me a young banana plant (Musa edible cultivar) in a small polybag. It was a tissue culture plant, produced for the banana plantations in Malaysia. I transferred the plant into the soil and within nine months it put out a huge inflorescence that developed into a large bunch of fruits (below left).

In June 2014 the oldest of my second-generation plants suddenly sprouted its inflorescence. I did not see it emerging from the top the day before but only the next morning when the huge inflorescence had turned downwards displaying its many bunches of fruits, each covered by a large purple bract (above right). I was extremely puzzled as to why I failed to notice the developing inflorescence until much later.

A few nights later, I was trying to photograph a bat visiting the flowers. Yes, the Common Fruit Bat (Cynopterus brachyotis) feeds on banana nectar and pollen and there are plenty around my place, even roosting in my porch LINK. I set up my camera on a tripod and as it was dark, my option was to make random shots at intervals of 15-30 minutes. There were bats flying around but I failed to photograph any visiting the flowers.

After uploading the photographs onto the computer, I reviewed the images. Imaging my surprise when moving from one image to another at a rapid pace, I realised that I had a series of time shots of the inflorescence showing the unfolding of the bracts from the closely packed head to exposing the respective sets of flowers. So I continued to make time shots of the inflorescence during part of the day and uploaded them as a video clip.

The above clip is in 3 sections: (1) general view of inflorescence, 2000-2145h; (2) Close up view, 2200-0045h; and (3) general view, 0715-1200h. Note that the active growing occurred during the night. During the day there was limited growth. So the banana inflorescence emerges mostly at night, as with the developing of the flowering head. This is understandable as the emerging flowers attract night flying bats that help in pollination. But in the case of the edible banana cultivars, the flowers do not need to be pollinated – the are parthenocarpic, that is, the female flowers do not need to be fertilised to develop into fruits, as with most other plants.

Besides bats, bees also visit the flowers (above).

Another bat, the Whiskered Myotis (Myotis muricola), can be found roosting in the young rolled up leaves of the plant. This small insectivorous bat is widespread throughout Singapore. I did succeed in seeing one but before I could photograph it, it flew off.

The banana plant is host to the Banana Skipper (Erionota thrax), also known as Banana Leaf-roller. The larvae of this butterfly hides inside leaf rolls, to emerge at night to feed. The larvae also pupate inside the leaf rolls.

The ripe fruits attract birds like Black-naped Oriole (Oriolus chinensis), Oriental Pied Hornbill (Anthracoceros albirostris), White-crested Laughingthrush (Garrulax leucolopus) and Yellow-vented Bulbul (Pycnonotus goiavier), among others LINK. Grey-breasted Spiderhunter (Arachnothera affinis), 
Little Spiderhunter (A. longirostra) and Spectacled Spiderhunter (A. flavigaster) have been reported to feed on the nectar LINK.

YC Wee
Singapore
June 2014