Sunday, April 27, 2008

Chek Jawa with the Naked Hermit Crabs, April 27 2008

Update: You can read more at Adventures with the Naked Hermit Crabs, and see some of the delightful new guestbook entries. Ria has also written about our voyeuristic tendencies and a sneak peek into the private lives of the hornbills over at the wildfilms blog.

Today, I spent yet another lovely afternoon on Pulau Ubin, guiding visitors around the Chek Jawa boardwalk with a few other Naked Hermit Crabs. Alas, my camera has gone a little bit crazy since my Semakau trip, so I didn't get to take any photos. The small handful of photos I took with my handphone camera will be shown further down, but let me warn you in advance, they do not depict a pretty sight.

I was originally intending to wake up bright and early and help Ria and July, who were having another guided session with Outward Bound Singapore (OBS). But true to my lazy nature, and my nocturnal habits, I decided to sleep in. I finally got up and headed for Ubin at noon.

As I was about to board the bumboat, I was puzzled to see a solitary large prawn (possibly Penaeus monodon) swimming around close to the berth. Very puzzling behaviour, especially since the prawn was hanging around just below the surface, close to a floating styrofoam box. I'm wondering if it happened to be an escapee from some angler's catch or bait box, or if it was actually a prawn that had managed to survive in these somewhat polluted waters.

Once I was on Ubin, I noticed two things: first was that the tide was very high, and the second was the jellyfish that was drifting around close to shore. I suppose jellyfish season is not over yet. I quickly joined July and Ria, and the OBS folks, who were over at the HSBC Volunteer Hub. There they got the unique opportunity to catch a glimpse of the nesting habits of the oriental pied hornbill (Anthracoceros albirostris), thanks to the cameras that have been set up at the nest boxes provided for these magnificent birds.

After lunch at Pak Ali's (yummy nasi lemak!), July, Ley Kun, Gaytri and I headed for Chek Jawa.

I guided a mixed group composed of young adults and a pair of elderly gentlemen, and they were fascinated with some of the things that I shared. Unfortunately, like last Sunday morning, it was high tide, and the colony of orange and porcelain fiddler crabs (Uca vocans and Uca annulipes) was once again completely submerged. At least the sand bubbler crabs (Scopimera sp.) that inhabited the high shore were a decent alternative.

Further in, the digger wasps (Bembix sp.) were busily buzzing around, though we did not get a chance to see them excavating their burrows.

The mangrove boardwalk proved to be very fascinating for the visitors; as I stopped to talk about fiddler crabs (a very tiny unidentified species was spotted at one stretch), we managed to spot a pair of giant mudskippers (Periophthalmodon schlosseri). And so while I moved on to talk about mudskippers, we got a real treat as a young Malayan water monitor (Varanus salvator) came swimming in from the mangrove creek, clambered onto land, and started foraging, oblivious to our presence. This spooked the mudskippers, which quickly put some distance between them and the reptile. After the lizard had vanished, the two giant mudskippers started to have a little territorial dispute, with mouths agape and dorsal fins erect, which in turn frightened the smaller dusky-gilled mudskippers (Periophthalmus novemradiatus). So in essence I managed to share quite a lot about three different mangrove inhabitants at a single spot!

At the shelter, one of the couples in my group had spotted some very small tree-climbing crabs (Episesarma spp.) in the mud, but I had decided to save my commentary until later, when the big ones would be seen around the mud lobster mounds. Big mistake, as that would be the only time I managed to see these crabs.

Further down the boardwalk, we observed a male purple-throated sunbird (Leptocoma sperata) as it flitted about.

But the real highlight of the day was to come just a few minutes after that. As I was walking with my head down, keeping an eye out for the elusive tree-climbing crabs, a large bird suddenly flew just overhead. At first, given its large size and dull plumage, I was wondering if it could have been an Asian koel (Eudynamys scolopacea), greater coucal (Centropus sinensis), or better still, a red junglefowl (Gallus gallus). But as the bird landed in a tree just off the boardwalk and turned its head to one side, the immense beak was unmistakable.

We had a hornbill. Hurray!

It seemed to be a juvenile, especially since it was quite small. It's a good sign that the hornbills on Ubin are breeding well, and hopefully, they will become much more common.

Despite my best efforts at trying to spot tree-climbing crabs, and encouraging my visitors to look out for them as well, I did not get the opportunity to talk about them. Ley Kun's group, on the other hand, managed to find them, after my group had passed through the area. But in any case, I think a hornbill is fair compensation for a lack of tree-climbing crabs, so there.

While we were up on Jejawi Tower, I heard some interesting bird calls coming from a coconut tree in the area, but could not see the source of the calls. Only when one of the birds took off and vanished into the forest did I realise that I had just seen my first wild hill mynah (Gracula religiosa).

The coastal boardwalk did not have much to offer in comparison, apart from a collared kingfisher (Todiramphus chloris), so while we walked, I just shared whatever I could about seagrasses, dugongs, coastal forests, and the beacons. My group was keen on finding out more about the shore walks conducted by NParks.

It was great that the golden web spider (Nephila pilipes) (along with her bevy of kleptoparasitic Argyrodes flavescens) was still there, right next to the trail at the end of the coastal boardwalk. The shrill buzzing of cicadas in the trees around us also gave me the opportunity to talk about the phenomenon known as cicada 'rain', (which others had the luck to witness).

While at House No. 1, and my group were busy filling in the guestbook, I looked out towards the viewing jetty, where a number of black-naped terns (Sterna sumatrana) could be seen flying about. It was a great day to see the terns as they flew above the water, occasionally even landing on the railings of the jetty. Suddenly, a white-bellied sea eagle (Haliaeetus leucogaster) soared into view, and I excitedly told my group, but they were so engrossed with decorating their pieces of paper that they didn't hear me, and the eagle soon vanished.

Unfortunately, there was a bunch of people who were not content with merely admiring the natural beauty of Chek Jawa. There was a pair of men who were trying to pluck coconuts with a razor blade tied to a long branch they had found, observed by several middle-aged women. This was taking place right in front of the back porch of House No. 1, where the visitors in my group were busily filling in the guestbook.



And then, to my horror, I saw the bottle they had placed on the wall, full of small marine organisms. There were several glass shrimp trapped within.


A pair of what I think were small thunder crabs (Myomenippe hardwickii).


There was even a goby (Acentrogobius nebulosus)! As well as a pair of purple climber crabs (Metopograpsus sp.), but they looked very dead.



I was upset, but not wanting to risk a confrontation, especially with members of the public around, I just took photos with my handphone camera. And since the people did not appear to be local, and because they did not react while I snapped away, I am hoping that they were just ignorant of the proper behaviours when exploring our nature areas. Not that it's really any different from deliberate poaching.

After some time, the group left, although I was too distracted to notice if they released the animals in the bottle, or decided to bring them home.

Subsequently, my group left, having thoroughly enjoyed themselves. July finally arrived with his group, and after that, Ley Kun's as well. The guides and several of the visitors who were still around were treated a spectacular aerial display, as the resident pair of white-bellied sea eagles began soaring over House No. 1.

Another hornbill was spotted, this time by July, as the minibus was turning into the Ubin town centre. Unfortunately, he was the only one who saw it.

And as the bumboat departed for mainland Singapore, I turned back towards Ubin, and watched as another white-bellied sea eagle flew over the boat, and headed inland, towards the heart of Ubin.

Today was yet another magical day out on Chek Jawa, full of new experiences, glimpses of the rich biodiversity, and an opportunity to share the beauty of the place with others. If only other visitors were able to understand and comprehend the destruction wrought by their thoughtless actions...

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