Nesting Behaviour of Olive-backed Sunbird

Olive-backed Sunbird nesting

Olive-backed Sunbird nesting

Olive-backed Sunbird is the most common Sunbird in Java. This bird can be easily found around human settlements. In the morning, this bird often usually sings on tree tops.  Olive-backed Sunbird eats nectar of flowers. Although this bird is not a long time hovering bird like Hummingbird, but this bird can hover briefly while sucking nectar from flowers.

Last month I found a nest of the Olive-backed Sunbird near my house. The nest was located in a big tree (Ficus sp). In that tree, there were vines that have been dried with a hanging position. The vines were used for the foundation of the nest. In the morning, the birds went to search for nest material and went back to build the nest. Approximately once in every 30 seconds the female Olive-backed Sunbird took the nest material. The nest material was from spider nets and dried leaves. When in the process of nesting, there was a male Olive-backed Sunbird around the nest. But the male birds did not help to make the nest.


Completed Nest

Completed Nest

Olive-backed Sunbird’s nests completed within 5 days. The position of the nest entrance was facing the sun rises so I have not see any activity of this bird since the nest already completed. There was no sign of Olive-backed Sunbird since that time.  But other birds such as the Olive-backed Tailorbird often nearby the nest of the Olive-backed Sunbird. Is it possible if  that Tailorbird leave eggs in the Olive-backed Sunbird’s nest?




Recording and Analyzing Frog Sound

Bufo biporcatus

Bufo biporcatus

Download : Bufo biporcatus amr , Bufo biporcatus mp3

Two weeks ago, after National Seminar and Congress Herpetology Indonesia 2013, there was a workshop on sound analysis of the frog. The workshop was held at the Banyuwindu Village, Unggaran, Semarang. Before the workshop, we were hunting herpetofauna. Herpetofauna in this area was very interesting, because we could find a lot of herps though only in the rice fields. Moreover, the species of herpetofauna in this area was also very diverse.

At that time, I tried to record sounds of frogs and toads that I found. Same with birds that sound look the same but different, the sound of frogs, too. If we recognize the sound of frogs one by one then we can clearly distinguish the character of each sound. The clearest sound that I record is Bufo biporcatus. Male frogs or toads generally make sounds to attract the opposite sex. But it is a weakness to frogs and toads to make sounds because they can be easily identified by predators. Beside the sound record I also got a photo moment when the frog made sounds. Note to those of you who want to record the sound of frogs or toads, you should turn off the flashlight or head lamp before recording because frogs or toads do not want make sounds when they illuminated by flashlight or head lamp.

The sound of frogs and toads can be analyzed with sound analysis software. At the workshop, we were taught how to analyze the sound of frogs. Frog sound analysis is important because it can determine whether the temperature, humidity, air, body size, etc. can affect the frog advertisement calls. The parameters measured include:

  • Tone per each sound sequence (calculated at every sound sequences, used average)
  • Call duration (calculated at every sound sequences, used average)
  • Note duration (calculated at every sound sequences, used average)
  • Dominant Frequency (calculated at every sound sequences, used average)
    Note: repetition rate ([number of tones in the sound sequences -1] / call duration

At the workshop, we used Raven Pro software. Unfortunately Raven Pro is a paid software, the price is $ 25 per year. While the only free software from Raven is Raven Lite 1.0. Raven Lite 1.0 cannot do a similar analysis as Raven Pro, so I could not continue my learning about frogs’ sound analysis after the workshop finished.

Download more sounds -> Download Link



Analyse Data

Analyze Data

Lost in Sumatra Jungle

Lake Ranau

Lake Ranau (Photo by : Umilaela Arifin)

The Beauty of Lake Ranau
June 17, 2013, we continued our exploration in Bukit Barisan Selatan National Park. On that day we headed to Lake Ranau. The lake was very beautiful, big, surrounded by mountains, and there was an island in the middle. The lake was very similar to Lake Toba in North Sumatra, but it is not popular so not many people know the beauty of this lake. We had lunch at the restaurant by the lake. The fresh wind that blew from the lake and beautiful scenery in front of our eyes made our lunch more enjoyable. After lunch, we took pictures at the lake. After that, the exploration team was divided into two groups. I entered the group members that were only 4 members. Most of the members wanted to go to the highest point in around Lake Ranau. My group destination was lower than the other group. Initially, I was happy because the altitude point of the group that I follow was not as high as the other group. Then in the middle of the track I regretted because the track was pretty tough. Steep incline made ​​me almost desperate. Until finally we reached the top of the highest point of our destination (1000 m asl) before dark.

The beautiful Blue-eyed Frog,  Leprobrachium waysepuntiense.
When it was dark, we started searching herpetofauna from that point while slowly descending down the mountain. Then,  I was surprised to see a litter frog. The frog was dark gray with blue eyes and lateral body glows blue when it was flashed on with a head lamp. I tried to take the photo. Then I gave it to Mr. Amir. He told that it was Leprobrachium waysepuntiense juvenile. He was the one who described the frog first in 2010. After that we found the same frog species but the adult. After that, the searching went smoothly. We found a snake Astenodiphas laephis, several Agamids like Gonocephalus sp and Bronchocela sp, and other frogs such as Philautus sp.

When we went down the mountain , we did not find a way out . In other words we did not know where we went through. GPS looks like did not work because we always find a dead end (cliff). This is Bukit Barisan, the hills lined up each other. All the hills in that area looks the same. Hills in north south east west had the same shape and vegetation. After that, we tried to follow the stream, hoping the stream end up to Lake Ranau. Around the stream we found a lot of frogs Leptophrine sp. Walking down the stream in a long time, finally we tried to look at the GPS. Obviously the streams leaded to the sea. In other words, we had been far away from Lake Ranau. It was around midnight and it started to rain. After that, we tried to follow the track that we had been through with cutting the track with climbed the hill and down the hill one by one. But we always found a dead end. There was always a cliff at the end of the track, so we tried to turn around and tried to do the same, up and down the hill one by one. But it turned out that we were just tracked around there although we felt it went very far. At that time, the time was at 2 am. We decided to take a rest. The place was on top of a rocky hill. I did not know how many leeches and mosquitoes which suck our blood that night. Our clothes got wet because of rain, sweat, and blood. We did not care about that. We just wanted to rest because we were very tired. We slept on a rock, without tents, jacket, and sleeping bag. We slept with a growling stomach.

Awakened by a Tiger
At about 4 am, we were awakened by the roar of a tiger. The tiger must already knew our location since we already entered its territorial area. When the tiger roared, not only human are silent by its roar, but also other animals like elephants, the crickets and cicadas also were ​​silent because of  the tiger roars. At that time, I was actually proven that the tiger is the “King of the Jungle “. King of the jungle told in stories always synonymous with lion. But lion do not live in the jungle, but in Savanna. Lion do not live in Indonesia. Therefore, tiger is the most deserves to be called the king of the jungle in Sumatra. Besides, the tiger was able to make living things around them to be silent. I can only pray at that time hoping the tiger did not come to us. If we are dealing with a tiger certainly we would not defeat it because we were very tired and hungry. Even if we were in good shape we will not be able to fight it because we were not kung fu warriors or Tarzan. In the story, there are only two people I know can fight a tiger with his bare hands, Tarzan and Chinmi ( Kung Fu Boy ). In the story of Shin Sukoiden there is a story of kung fu warrior that fights the tigers, but they use weapons, such as spears and swords. Finally, I pray until half asleep. I was awaken at 6 am and the sun began to rise. We survived from the threat of tiger. Because it was already morning, we just realized that we slept beside a cliff.

Searching a Way Out
Around 7 o’clock we decided to continue the search of the way out. We came down the hill to find a stream. We drank as much water while eating the rest of the snacks that we brought. Although only a little, the snacks could add to our energy on that morning. The stream was located in the valley between the hills that look the same. At that time the stream was very beautiful with morning sunlight. Above us, there were a lot of birds chirping. Hornbill with large numbers passed over us and perched on top of a large tree. Hordes of Siamang Gibbons scream loudly on the big trees. That forest’s the most beautiful forest I have ever seen.
We continued to seek a way out. When the water supply ran out, I drank water from the water on the leaves. We tried to eat whatever we can ate to add energy. At 12 am, we reached the top of a hill and had visible views of Lake Ranau. We continue walking down the forest and finally few found a way out of the forest around 2 pm. We lay down beside Lake Ranau while thankful to God we’re still alive after what we’ve experienced in the forest.

Expedition Members: Amir Hamidy (Lembaga Ilmu Pengetahuan Indonesia), Utpal Smart (University of Texas at Arlington), Umilaela Arifin (University of Hamburg), Kemal Iqbal Nawie (Brawijaya University), and a Guide from Bukit Barisan Selatan National Park.

Leptobrachium waysepuntiense - Bukit Barisan Selatan National Park

Leptobrachium waysepuntiense – Bukit Barisan Selatan National Park

Sleeping beside the cliff

Sleeping beside the cliff (Photo by : Umilaela Arifin)

After sleep with desperate faces

After sleep with desperate faces (Photo by: Umi Arifin)

Drinking a lot of water

Drinking a lot of water (Photo by : Umilaela Arifin)

Beautifull stream and forest

Beautiful stream and forest (Photo by : Umilaela Arifin)

Finally, a way out

Finally, a way out (Photo by : Umilaela Arifin)

Bird Lovers

Tradition of keeping birds in cages in Indonesia
Bird lovers in Indonesia are known to be people who keep birds in cages. Keeping birds in cages has become a tradition for the people of Indonesia, especially in Java. According to Javanese traditional assessment, someone has considered perfect if he/she had had five points, namely: Wismo, Wanito, Kukilo, Turonggo and Curigo / Keris.

  1. Wismo means house. Someone who already has house exactly has enough income and life is well established.
  2. Wanito. Someone who has been married and had a wife (as well as of course a woman who has been married), it means choosing the right way of life and responsible.
  3. Kukilo means bird. The philosophical explanation is: Bird’s singing is melodious like music. To hear a soft voice, someone feels calm, good, and happy. How beautiful, if a father, patriarch spoke in a soft voice, it’s certainly very calm and pleases the entire family.
  4. Turonggo means horse. Transportation horse is a practical tool in the past. He can be used to pull carriage or ride for traveling. In this case, the vehicle should have a life (having a way of life) that can be well controlled so that someone’s life is well established.
  5. Curigo or Keris. Kris (traditional dagger in Java) is sharp at the edge. It symbolizes sharpness of thought. It is very important that someone has a sharp mind with extensive knowledge.

From the five assessments above, three of the five points assessments (Wismo, Wanito and Kukilo) are likely still maintained by many Javanese.

Market demand and supply
Bird trade to keep in bird cages is very alarming. A organization network that collect birds can collect millions of birds a year and being sold include cockatoos, parrots, starlings, sparrows, finches, white-eyes, thrushes, cuckoo and partridge. Birds in cages are popular pets in Indonesia. Birds are kept to meet domestic demand together with the amount exported. Some species of birds are reported almost vanished due to this activity, for example Straw-headed Bulbul, starlings, White-rumped Shama, and Zebra Dove. It should be noted that the current stock market is also a lot of birds imported from China. This may indicate that domestic resources are insufficient to meet the demand anymore.

Bird lovers in Europe
Unlike Indonesia, in Europe bird lovers are known as the birdwatchers. Birdwatchers are people who observe bird in the wild. Observations activities referred to bird watching. They do bird watching as a hobby, no matter old or young, bird lovers in Europe love birds by letting birds live freely in the wild.

Is tradition of keeping birds in cages can be stopped?
In my opinion, the tradition of keeping birds is now incompatible with the increasing of degraded nature condition. In contrast to the condition in the past when the birds are still many around us as well as the habitats were still good. Now, the birds are hard to find around us. Bad tradition can be stopped because it is not taught in any religion. In Islam, if we keep animals, then all of the animal rights should be fulfilled. Are we able fulfilled all the animals rights that we keep including the right to reproduction?

It’s time to change from bird keeper into birdwatcher
With the decreasing habitat for birds and increasing of bird hunting, the tradition of keeping birds in cages should be stopped. Instead, our way to love birds is to watch the birds fly freely in the wild. It’s time we change into a birdwatcher. If your friend or parents keep birds in cages, do not copy it. Start of ourselves to observe birds in the wild. Spread your bird watching hobby to the people around and your future offspring. Let us and our future generations continue to fix the tradition “bird lovers” by observing birds in the wild. Let the wild take care of them.



birds in cages

birds in cages

The Changing of Scaly Thrush Foraging Location in Cangar

Scaly Thrush Foraging on garbage

Scaly Thrush Foraging on garbage

Initially in the open area
Scaly Thrush was often found on the ground. These birds foraging on the ground to search earthworms. In the rainy season these birds will be easy to find. This is due to the wet ground will allow the bird dig easily to get the worms. Even if it is rain the birds will easily approachable. My friend even approached this bird easily from 2 meters when heavy rains.

Moving to a garbage dump
Finally, two weeks ago we rarely found these birds in the previous spot. These birds moved to find food in a garbage dump. I was very surprised when these birds foraging among rubbish. The birds foraging there even though the place was surrounded by thick smoke from burning trash.

Some possible causes of moving foraging location: 

  1. Foraging has been pressed against the large number of visitors.
    Cangar were increasingly crowded by tourists. These birds were afraid because of the possibility of humans around the site looking for food. So that the birds were looking for another location that is not open, garbage dump.
  2. Growing number of cats around.
    Cangar cat population was highly increasing. The cats were eyeing the birds that like to got down on the ground looking for food. Therefore, Scaly Thrush moved to another location that was not open to avoid the cats.
  3. Looking for other kind of food from the garbage.
    Scaly Thrush possibly searched for other food like maggots in the garbage. But, whether maggots can be used as a substitute for an earthworm? In my opinion, earthworms remain a favorite food for these birds. I still found these birds were looking for earthworms in another spot in Cangar although not as frequently as in garbage dump. Is this bird tried to search human leftovers in the garbage? According to my friend, Island Thrush in Ranu Kumbolo often found eating human leftovers like rice and instant noodles. Although Island Thrush is different species of bird, it is still in one Family with Scaly Thrush. Originally they were used to eat earthworms, but found other foods such as human leftovers. Were those being substitute foods or just extra foods? I think those were just extra foods. The habitat around was still very good for the birds to look for their main food.

Maybe, There’s more possibility of the moving foraging location of Scaly Thrush. Therefore, we need further observations on the behavior of the Scaly Thrush in Cangar.

Scaly Thrush eating worms

Scaly Thrush eating worms

Differences between birdwatch shorebirds and forest birds

WimbrelsLast Sunday I tried to birdwatch shorebirds in Wonorejo Surabaya for the second time. I found it difficult to take a picture of shorebirds there; because the open area makes these birds easy know our existence. So those shorebirds that I wanted to observe and document are easily escaped. Last week, in Cangar I easily observed and documented forest birds. I even did it with mobile, walked around to look birds. From my experience in both places, I got a lesson that there are differences to birdwatch shorebirds and forest birds:

1. Techniques (mobile or stay at one spot). The habitats for shorebirds generally open so we have to determine the location of the observation point first and stay in the first place. The Observation point should be protected by shrubs or trees so that the birds will not easy to know our existence. Unlike the shorebirds, the forest bird observation does not have to stay in one spot. We can find more species by moving. When we find the bird, we can quietly approached the bird because many plants around us can be used for hiding.

2. Observation instruments (monocular and binocular). On shorebirds, we should observe birds by using monocular. Monocular are generally able to see objects farther than binoculars. The monocular should also be equipped with a tripod so that we can easily make observations while we stay in one location that we have set before. In addition, by using the monocular we can easily count the number of birds at the site location. Unlike the shorebirds, forest birds should be observed by using a binocular. Binocular would be very useful if we observe with mobile technique in the forest.

3. The movement of birds (fast and slow). Shorebirds generally not as fast as forest birds. If there is a group of birds that had been stay in one location to find food, then we will easily observe the birds. The movements that are not fast will allow us to observe and document them. Whereas forest birds, generally is always moving from one tree branch to another branch so we have to quickly observe and document them.

4. Color (uniform and colorful ). The color on shorebirds generally uniform: white, brown , black , and gray. This is a difficult for birdwatchers if they are not used to be to identify these birds. Differences in these birds are generally found in shades of the feather. While forest birds are so colorful so that will be easy to identify the difference of the species. But, generally female forest birds like Flycatcher do not have as good color as male birds. So that it would be difficult to recognize the females.

5. Escape. One bird escape, every birds escape. That’s what happened to a group of shore birds that I observed. Whereas forest birds, one bird escape is not a problem because there are still other birds.

The description above is my personal opinion based on my experience. Therefore, both the difficulty and the easiness at different places is a matter of each birdwatcher. Some birdwatchers found it easier to observe shorebirds, some the opposite. Well, I think it depends on our habits. For me, the forest birds are easier to observe, although my eyes are not quick enough in identifying them. Shorebirds color pattern are uniform so that they are not easy to identify, otherwise forest birds are so colorful so they are easy to identify. Perhaps this is because I more often make observations in the forest, so I ‘m used to identify forest birds.

one of the forest bird, Grey-headed Canary Flycatcher (Culicicapa ceylonensis)

one of the forest bird, Grey-headed Canary Flycatcher (Culicicapa ceylonensis)


one of the shorebird, Little Tern (Sterna albifrons)

Rana hosii, from Java to Sumatra

Rana hosii from Bukit Barisan Selatan National Park

Rana hosii from Bukit Barisan Selatan National Park

In June-July 2013, when I joined the  herpetofauna exploration in Sumatra precisely in Bukit Barisan Selatan National Park, I often found Rana hosii. This frog had green color and very abundant in fast stream habitats around mountains. Commonly found on the rocks stream to the plants around the stream. Because of the high abundance, we did not take a lot of samples of this frog because it was already too many Rana hosii samples collected.

Two weeks ago , I visited my friend’s house at the foot of Mount Welirang. He brought me into the primary forest to explore herpetofauna there. I was escorted by him down to the fast moving mountain stream. I thought I would get a lot of Rana hosii in the stream as I got in Sumatra. Sure enough I found a lot of this kind there.

The finding in this two places, can be concluded that there  are some differences:
1 . Abundance. In Sumatra we could easily find Rana hosii not only in primary forest but also in secondary forest. While in Java, it is very hard to find in the secondary forest. I had to enter the good forest area to find this kind of frog.
2. Color. In Sumatra we often found Rana hosii in green sides as green as the back side while in Java I found Rana hosii in green on the back only.

Rana hosii from Mount Welirang

Rana hosii from Mount Welirang

Rana hosii is said to be a poisonous as the English name “Poisonous Rock Frog”. But the poison has no effect on humans when humans touch it, not swallowing it. The poison may effect on insects and other frog that attach to the skin or animal that hunts it. Therefore, the abundance of these frog in their habitat can be caused by a form of self-defense mechanism of the poison. Regarding color, according to some sources that I read, Rana hosii indeed have a lot of color variation. According to Iskandar (1998), in his book The Amphibian of Java and Bali, mentioned that in Java Rana hosii mostly in green sides as green as the back side. Possibility the writer took many samples from West Java which is closer to the Lampung area where I found a lot of Rana hosii with uniform color. But it is not the same with in East Java, where I found just a lot of green color only on the back side.

Reference: Iskandar, D T. 1998. The Amphibians of Java and Bali. LIPI. Bogor.

Fast-moving Stream in Sumatra

Fast-moving Stream in Sumatra