The papaya (Carica papaya) is native to tropical America. Brought to this part of the world during the 16th century by the Spanish, it has since spread throughout the tropics. This spread is mainly due to humans who grow them in home gardens and farms for the fresh fruits.
Birds love the fruits, from the common Javan Myna (Acridotheres javanicus) (top left) and Yellow-vented Bulbul (Pycnonotus goiavier) (top right) to not so common hornbills and barbets.
Although we know what species of birds eat the fruits, do we actually know whether these birds eat the seeds as well? And in the process help disperse the seeds? These seeds are covered with a thin layer of translucent flesh and are attached to the inner surface of the seed cavity by fleshy strands (below). Thus when a seed is removed it brings with it a few neighbouring seeds.
Mostly, the birds peck on the fruit, filling their bills with the soft flesh. The bulbuls feed singly or in a pair, taking beak-full of flesh and flying off to feed the chicks in the nest. They return every few minutes to repeat the process. If the mynas are at the fruit, the bulbuls wait patiently for their turn. The seeds are usually left alone until the birds finish eating the surrounding flesh. Then they began pecking around the area where the seeds are. Only then will a few seeds get removed and eaten. But do the seeds pass through the alimentary system unharmed to subsequently germinate?
YC Wee
Singapore
May 2010
10 responses
If the seeds are swallowed they will certainly pass through a bulbul gut undamaged. Gut passage only take about 15-20 minutes in a bulbul and all the tissues in the gut are soft (unlike, say, a green pigeon, where there is a muscular gizzard which few seeds get past).
How about the bulbul’s gizzard? It may not be as muscular as the pigeon’s but will it do any damage to the soft seeds of papaya?
Have you any idea why bulbuls also eat papaya leaves? They regularly shred the leaves until there is nothing left – they are not eating insects. Is it a way to clean their bills or do they enjoy the taste?
I have yet to witness bulbuls eating my papaya leaves. If you have images of the bird eating and the plant devoid of leaves, we would love to post the account. And hopefully some readers may know more?
After reading the report above I am almost certain that the bulbuls eat my pawpaw leaves .especially young trees
Some birds do eat leaves or peck at leaves crawling with insects…
I feel many frugivorous birds must be swallowing papaya seeds that may be passing through the gut unharmed. Here in North Kerala, India, the large green barbet is the most common bird seen feeding on papaya fruits and you would find papaya seedlings germinating spontaneously in homestead gardens where the birds might defaecate.
Thanks. Good to know.