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One of the remaining large trees, Ficus caulocarpa (大葉雀榕): Journal over an 18-day period.

Author: Jennifer K (ecologist)

In this article, I share my experience observing a fig tree, Ficus caulocarpa, and its relationship with the environment and animals surrounding it. My task was to keep an eye out for macaques (the formosan rock macaque, Macaca cyclopsis) and to keep them away from the fig. During those three weeks, several points have caught my attention, which brought me to share these observations and thoughts. I start with introducing the tree and a summary of main patterns I have observed while I was stationed by it all day. I gradually redirect the topic of the article to a discourse in the potential environmental degradation given the land-use history of the area. I end the article with my opinion, some personal doubts, and concerns. What you can expect from this article is a mix of descriptive documentation, few supporting information, and a personal perspective.

Ficus caulocarp (stem-fruited fig), family Moraceae, is a strangler fig native to several Asian countries, such as Sri Lanka, Malaysia, Japan, Singapore, Indonesia, Taiwan, New Guinea, etc. It is considered a lowland tree species that can be found near coastal areas, side roads, and forests. This species likes warm and sunny weather with minimal rainfall. One interesting fact about F. caulocarpa is that it starts its life cycle as an epiphyte, deriving all its nutrients from its host tree and eventually killing it in the process. It can take many years for its aerial shoots to reach the ground. These aerial roots grow away from the main stem (Fig. 1 below).

Just like other fig trees, its flowers and seeds are found within the fruit, the syconia. They are widely known to be pollinated by specialized wasps. Abundant and generous fruits grow on the stems of the tree (Fig. 2) The small size of the fruit attracts small dispersers (more on that later). Various fig species can be found all across Taiwan. From my investigation, knowledge about the phenology or growth of figs in Taiwan, especially F. caulocarpa, is limited. I was able to find one study that monitored the phenology of F. caulocarpa for almost 4 years, stating that it fruited all year long (Chiang et al. 2018). Another study compiled all the different pollinators of every native fig species in Taiwan (Bain et al. 2015). This study listed 4 species and/or genus (currently recorded) of wasps that pollinate F. caulocarpa. However, it may likely be that banyan trees can keep growing if conditions are favorable throughout their lives. In Taiwan, F. caulocarpa can be found in parks, mountains, and urban areas. While the social and cultural significance of F. caulocarpa in Taiwan is unknown, in Thailand, for example, some F. caulocarpa species are considered sacred (Chantarasuwan & Van Welzen, 2012).

As fig trees are diverse and prevalent in many asian countries, they are considered keystone species by offering resources to many fauna and serve as medicine to people. Investigating the medicinal and cultural uses of fig species in Taiwan would be valuable for local economies.

As a deciduous tree, March was the time where senescence occured for this particular individual. My presence by the tree acted as a defense against Macaques, which according to local knowledge, eat all the new shoots quite quickly, posing a threat to the growth of this large tree. While I had doubts on whether Macaques truly pose a threat, my time there had been successful and insightful. Over the course of three weeks, I stayed close by all day throughout the day being grounded with my senses heightened for sounds and movement.

Daily visitors

At different times of the day, and more likely in good weather, several animals visit F. caulocarpa and eat its fruits. I wasn’t able to identify whether fruits matured synchronously as the tree was large and the backlight from looking up through the binoculars didn’t help at all.


Almost on a daily basis, groups of black bulbuls and Chinese bulbuls temporarily perch and linger on the branches of the tree, feeding and making calls. Other common birds I observed were treepies and Taiwan barbet. I once saw a female maroon oriole, woodpeckers, and a long-tailed minivet on the tree. Given the small fruit size, one would expect to find dispersers with suitable beak size. However, since these fruits are so abundant and prevalent on all branches of the tree, it also attracts bigger frugivores with bigger beaks such as the treepies and Taiwan barbet. In other Asian countries, even hornbills are recorded to eat F. caulocarpa's fruit, although less common. It is known that fig trees are important resources for urban and lowland birds, because they produce an abundant number of fruits all year round in Taiwan (Walther et al. 2018).


I know very little about squirrels and their behavior. Fortunately, I was given much space to observe their foraging behavior and listen to their calls. One startling discovery is that for the longest time, I confused the sounds of squirrels with Macaques. I never expected them to make similar and loud calls. There were a few times where I mistakenly scared squirrels away, assuming it was a Macaque. Their movement also make loud sounds of branches and leaf movements, loud enough to assume it a macaque movement. Surprisingly, squirrels were constantly present despite weather conditions, foraging from branch to branch and eating the fruit (and the occasional freezing in place or running away from me).


Macaques would call early in the morning, between 5:30 to 6:30 AM and sometimes still make calls until 10 AM. I only once encountered 1 or 2 macaques on the fig tree (I couldn’t see clearly as I was a little late putting my glasses on). When I unzipped the tent to look outside, a group of Macaques were shocked and ran away as soon as I shouted, “HEY!”

I did not notice any signs of feeding marks after inspection, although in my time there, I observed only 1 branch which lost all its shoots. While it was my task to keep an eye out for macaques eating the growing shoots, I was never told that they would be interested in eating the fruits. After some research, I discovered that one study reported that the Sulawesi crested black Macaque (Macaca Negra) in Indonesia fed on the fruits of F. caulocarpa (O’brien & Kinnaird, 1997). Since my encounters with macaques were minimal, I could not testify to whether they truly feed on shoots and/or figs. The branches of F. caulocarpa were thick, several of them extending horizontally outwards, seeming as an appropriate tree for macaques to sit or even sleep in. Interestingly, one study showed that spectral tarsiers in the Philippines preferred sleeping on Ficus trees, one of which were F. caulocarpa and are a part of the tarsiers’ polygomous mating systems (Gursky-Doyen, 2010).

Other animals I observed visiting the tree were thumb-sized hornets (mostly predating on bees), wasps, horseflies resting, butterflies flapping around fruits, and flying squirrels at night. One day I noticed several shoots on the ground that had bite marks (Fig. 3 below). According to Mr. Lai, the farmer and owner of Juhu Ecological Park, he suspected it might be flying squirrels. It makes sense since I only noticed new shoots dropped during the day and it did not look like Macaque biting marks. Since I picked them up, I saw more and more for several days. On a funny note, I think hornets may like the aroma of coffee.

A home for some

Trees are known as a home or an ecological niche for various species across the world. They provide the nutrients, shelter, and/or other resources to safeguard species from their competitors, ensuring a home for different species. This concept is also known as niche differentiation. For this particular tree individual, it is a home for bees and ants.


One fascinating feature of this tree is what lies within the hollow space of its main bark, a bee hive (Fig. 4 below). The size of the beehive cannot be determined as the inside cannot be made visible. I spent as much time observing birds as I did the bees. I found them inspiring, beautiful and sometimes even cute when they would carry pollen on their hind legs as two bright orange dots.

I once observed a hornet flying to the entrance of the hive. At first, I wasn’t certain what it was doing there. Then, I discovered it was trying to snatch a bee. Several bees were combating the hornet in defense, attempting to save its partner bee, now in the grasp of the hornet, while also being cautious not to get too close. In awe, I learned that bees showed signs of caring for their conspecifics. Some even chased after the hornet, still trying to save the captured bee. I followed the hornet. It landed on a big branch not too far from the beehive and nibbled (or snipped) its way, devouring the bee, bite by bite. And then it flew away. Once I was aware of this phenomenon, I would sometimes sit by the beehive in hopes to observe this again. And I did, a total of 2 or 3 times.


From my observation, ants in uniform lines marched in an organized fashion and were as busy as the bees. It seemed that their destination never-ended. It is common knowledge that each ant that passes by another quickly identifies the other through chemical and sensory communication. I wondered how far their home-ranges were and to what extent would they venture to find resources.

Neighboring trees

On my third day, a circular plot was made with a radius of 10 meters. The 10-meter radius was because F. caulocarpa's roots visibly extended outwards in all directions minimally at that length. I was speculating. Through this tiny experiment, I would get to identify the tree’s neighbors and be a step closer to speculate on its relationship with its neighbors. By understanding the composition of this tiny area, I would be able to better make sense of my observations on the ridge. Within this circular plot, 11 tree species were identified (with a dbh of >1 cm at breast height, 150 cm).

The list of species were the following: Lagerstroemia subcostata (九芎), Ficus ampelos (菲律賓榕 ), Murraya paniculata (月橘), Ficus septica (稜果榕), Celtis sinensis (朴樹), Ardisia virens (黑星紫金牛), Cinnamomum camphora (樟樹), Machilus kusanoi (大葉楠), Litsea hypophaea (小梗木薑子), and Ficus irisana (澀葉榕).

Several tree species were flowering at the same time, namely, Cinnamomum camphora, Acacia confusa, and Melia azedarach. These trees could also be a resource for the bees. In the course of three weeks, I have trained my acute nose in identifying various aromas of these trees. I was reading “Thirteen ways to smell a tree” by David George Haskell, a knowledgeable and captivating writer who writes books about the ecology and cultural and social relationships people have with trees. It was thanks to this book that I was able to more deeply appreciate and be aware of how close we are to trees just by the act of smelling, and essentially breathing among them.

Herbivores present on the ground

Most of the days alone were spent quietly. Under silent and careful watch, most of the animal movements can be observed at a close distance. I have come close to observing muntjac’s foraging on litterfall. I discovered that they made different kinds of calls (for perhaps different purposes). I saw a mongoose just 10 meters away from my tent. I once heard wild boars running away from me. Needless to say, even if I don’t get to see wildlife for prolonged periods of time, if one is a proficient tracker, you can very obviously tell that these animals are active in this mountain. Their footprints and marks are prevalent. From my observation, muntjacs, boars, and squirrels are common. Interesting study goals would be to estimate relative abundances these mammals and learn about their effects on tree recruitment, forest health, and their ecological function.

Fig. 5 Female muntjac (left) and male muntjac (right) 15 meters away from my tent.

Ecological questions of concern

The earliest land-use history in record dates back to the 1940s. Han people started expanding their agricultural practices all throughout the lowland East coast of Changbin. In Juhu farm, events of deforestation for agriculture have been patchy since then, some dating as close to 20 or 30 years ago as the last deforestation event. As a consequence, many patches in the mountain are young forests, whereas some are older forests. The species present in Juhu farm are mostly considered part of the younger stages of forest growth, as most trees are thin and not tall to support this claim. Some speculate that this is due to the local landscape, facing the pacific ocean, climate change, or excess herbivory activity (or a combination of these). The local farmer has even shared that even bird species have not been present anymore (due to high nest predation rates by macaques studied by Mr. Lai's daughter). Given all the proclaimed observations over the last decade by local people, lowland mountainous forests in Northern Taitung are perhaps really losing their biodiversity.

Overgrazing, lowland degradation & biodiversity loss

From my own observation in those three weeks, I can testify that overgrazing is very likely one of the key factors driving the forest. Muntjacs and boars are abundant here. Seedlings or juveniles of tree species are scarce on the forest floor. Older growth trees are not present. However, there is very little scientific-backing for any of these observations and posed threats. I could also testify that bird diversity in Juhu farm is not high, according to my bird call identification skills and using the BirdNet app. Biodiversity loss of plants and animals can directly and negatively affect local communities’ livelihood such as their economy and health.

F. caulocarpa is one of the fortunate trees to have been spared. What would the forest have looked like a hundred years ago? Juhu Ecological Park is unfortunately not the only local area to have these potential environmental issues. I have observed similar conditions and even worse in many parts of Taiwan when I venture out finding tracks to hike on. Hualien may be one of the few places that still has relatively healthy lowland forests along rivers and neighboring agricultural land. There is big potential for JEP to be healthier and more productive to meet all of the local community’s developmental goals.

Personal gain and challenges experienced

I end this article with a personal reflection on the impact of this experience on me. I truly intended that this period of solitude and silence would somehow declutter my mind and alleviate my anxiety issues. However, that didn’t occur. I learned, even more, the importance of taking care of my mental health and the thoughts that occupy the mind. From an ecological lens, this experience was another proof of how important it is for a country like Taiwan, with so much potential, to protect biodiversity and to initiate restoration efforts of degraded lowland areas. Local communities taking action to manage their land and mountain range is the true solution to sustainable land use.


  1. Bain, A., Tzeng, H. Y., Wu, W. J., & Chou, L. S. (2015). Ficus (Moraceae) and fig wasps (Hymenoptera: Chalcidoidea) in Taiwan. Botanical studies, 56(1), 1-12.

  2. Chantarasuwan, B., & Van Welzen, P. C. (2012). Which species of Ficus subsection urostigma in Thailand are used as food, ornamental plants or sacred trees. Thail Nat Hist Museum J, 6, 145-51.

  3. Gursky-Doyen, S. (2010). Intraspecific variation in the mating system of spectral tarsiers. International Journal of Primatology, 31(6), 1161-1173.

  4. O'brien, T. G., & Kinnaird, M. F. (1997). Behavior, diet, and movements of the Sulawesi crested black macaque (Macaca nigra). International Journal of Primatology, 18(3), 321-351.

  5. Walther, B. A., Geier, J., Chou, L. S., & Bain, A. (2018). The figs of winter: Seasonal importance of fruiting fig trees (Ficus: Moraceae) for urban birds. Acta Oecologica, 90, 28-34.

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