IT was some 30 years ago when I first experienced the magic of the Miri River. It was just after my marriage and my father- in-law often travelled along the river. My in- laws had a pineapple farm at Sunday Mali, a tributary of the Miri River. On the weekends, I used to follow him by boat to the farm and we normally went paddling back home to Pout Corner.
We would paddle after sunset and sometimes reached home around 10pm. I remember very well that both sides of the riverbank used to glitter with the light show of fireflies.
As my father-in-law was a superstitious person, he would remind us not to disturb them and be content to just watch and enjoy the show.
According to him, the trees that harbour fireflies have owners. By this he meant that they were ‘haunted’. It was enthralling to see the fireflies flickering in a group with such perfect synchronicity.
Sometimes, at night, we went out to catch prawns with homemade ‘serampang laut’ along the Pujut-Lutong section. The area was also full of firefly displays, but this was some 30 years ago.
On a recent fishing excursion along the same river, I did not notice fireflies, perhaps I just wasn’t paying enough attention. I will go back.
Fifteen years ago, at the height of my prawn fishing craze, I travelled sections of the Suai River; and it used to be lit with firefly displays as well.
We would drive to Kampung Iran from Miri, which is about 130km away, and would be at the water’s edge by midnight. We would then get on our perahu and paddle to the best prawn sites. All the way to these sites, congregating fireflies lit up the riverbanks.
One evening, our boat engine broke down near Pasir Puteh, some 15km from Iran, and we were forced to paddle our way up river. The riverbanks then were glittering with fireflies. This kept us buoyant and at ease as we made the strenuous trip upstream.
Recently, I attended a Firefly Workshop organized by the Malaysian Nature Society (MNS), Conservation Division with several key firefly experts from Universiti Malaysia Sarawak (Unimas) and MNS. The Institute of Biodiversity and Ecosystem Conservation (IBEC) hosted it along with Unimas, led by Dr Andrew Alek Tuan.
The workshop was supported by experts, among them entomologists Dr Mahadimenakbar Mohamed Dawood of Universiti Malaysia Sabah; Wan Faridah Akmal Wan Jusoh of Universiti Putra Malaysia, and MNS Conservation Division senior conservation officer Sonny Wong.
It was really an eye- opening workshop and proved to be a new learning high for me.
We attended a series of talks and watched slide shows, followed by fieldwork of the first fireflies ever recorded in Sarawak at Sungai Buntal in Kuching.
We came across 90- display trees along each side of the river. The total distance covered was about 10km. We saw that there seemed to be two or more species of fireflies, because of the different flashing patterns.
To positively identify a firefly, samples need to be captured. The specimens are then examined under a microscope. It’s possible that the identity of fireflies discovered that day were different from the ones originally catalogued.
Fireflies are actually beetles, not flies. Entomologists know them better as beetles from the family of Lampyridae.
The most known firefly species are bioluminescent as adults. Less known, however, is that all known firefly larvae and eggs are bioluminescent. Fireflies are one of the indicator species of the health of a river system. The presences of fireflies indicate that the river is clean and supports a healthy mangrove system.
The life cycle of the firefly begins with the eggs in the mangroves, some 100 metres from the maximum tide level, as this ensures the eggs are not drowned during the high tide. The eggs hatch into larvae and feed on tiny snails.
It takes three to four months for the larvae to pupate into adults. The adults emerge and fly to the display trees where they attract mates. After mating, the females then lay their eggs and thus the whole cycle of firefly life begins again.
A firefly grouping on atree is called a congregating firefly. The tree is then known as a display tree. The commonly used display trees are Berembang or mangrove apple, locally known as Buah Pedada (Sonneratia caseolaris). Fireflies also prefer younger trees.
Each species of firefly communicates through unique flashing patterns. Most rivers in Sarawak once supported huge Berembang tree populations. However, they were heavily harvested for use as pilings for buildings and the local charcoal industry.
For many years huge swaths of mangrove swamps in Sarawak were destroyed in this way. Many firefly congregations were also destroyed together with the mangroves in the process.
After the Fireflies Workshop, I pledged to get back to the rivers where I used to see these fascinating little creatures. High on my target list are rivers in Miri, Suai, Bekenu and Niah areas.
I will endeavour to share the knowledge gained with the locals and impress on them the importance of fireflies and our river ecosystems
FIREFLIES WORKSHOP: Participants of the workshop learned more about these fascinating creatures, which are an indicator of the health of a river system.
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