A unripe female Ficus barba-jovis at Tabin in Sabah. This unripe fig was knocked down by an orangutan feeding on a ripe fig.
Ripe figs are glossy purple black as shown in the photo below
All photos by Dr Zainal Zahari Zainuddin the BORA site manager of the fig orchard at the Sabah Ficus Germplasm Project.
You can tell that this female fig is unripe because there is still latex in the flesh.
The black markings among the bracts of the ostiole are probably female fig wasps which died in a failed attempt to enter the fig. The description below refers only to the pollination of dioecious figs where fig trees and their figs are either male or female. The majority of Bornean figs are dioecious.
These female fig wasps are attracted to the fig by the scent which is species specific i.e. each fig species has different scent which only attracts one species of fig wasp. Female fig wasps cannot tell if they are entering a male fig or a female fig so they arrived equipped to deal with both possibilities.
Female fig wasps hatch in the gall flowers of male figs. Before leaving the male fig through the ostiole they mate with hatched male fig wasps and they brush against the pollen carrying male flowers inside the male fig. Thus when they arrive at another fig of the same species they are equipped to deal both with pollinating the fig if it is female or laying their fertile eggs if the fig is a male
If the fig is a female as in this article the female fig wasp enters the fig through the ostiole but is unable to lay its eggs in the female flower ovaries (the bright red oval objects in the photo below) because the wasp’s egg laying tube (ovipositor) is the wrong length. In a desperate search before it dies the female fig wasp crisscrosses the interior surface of the fig trying but failing to lay its eggs. Instead the male pollen it carries is deposited on the stigmas of the female flowers thereby pollinating the flowers which will then produce one seed to each ovary. The female wasp will then die inside the fig with its eggs remaining unlaid.
These are the yellow bracts of the ostiole surrounded by the tiny female flowers with red ovaries and yellow styles tipped with yellow stigmas which line the interior of the fig. Female fig wasps carrying pollen from a male fig force their way into the fig through the bracts of the ostiole and deposit the pollen on to the stigma of the female flowers, thus pollinating the flowers. Each of the pollinated flowers will then produce a single seed inside the tiny red ovaries.
Unripe female fig dropped by a feeding orangutan. Orangutans eat both ripe and unripe figs. They therefore act both as seed predators and seed dispersers of figs in Borneo. As gibbons can only eat ripe figs the orangutans get first choice of any fig crop.
Ripe fig seeds from a piece of ripe fig dropped by an orangutan.
Each fig seed shown above against a mm scale is approx. 0.5 mm wide and 1.5 mm long. The ” wing” surrounding the seed is believed to assist ants to help carry the seed back to their nests. Ficus barba-jovis is a root climber which starts growing in the ground up the trunk of a nearby tree. When the climber reaches the canopy it grows branches out sideways and the the original root detaches from the tree trunk, thickens and starts producing figs. It has been estimated that Ficus barba-jovis produces four crops of figs a year . Each crop lasts around 4 to six weeks only with one or two figs ripening every 24 hours. Thus one liana can produce a steady supply of food for local animals for around half the days in the year
Dr Zainal estimates that there are around 144,000 Ficus barba-jovis fig seeds in this tray. The produce of the equivalent of a single large female fig approx. 7 cm in diameter.
Ficus punctata seeds germinating in sunlight after 5 weeks on wet tissue.