Tuesday, March 26, 2013

Singapore: On the Boardwalk

After our brief tour in New Zealand, Eileen, Ryan and I flew back to Singapore for a few days with Eileen's cousin Chris Chang and his family. Chris very kindly agreed (on December 21, 2011 - I suspect this blog will never be up to date) to indulge my taste for nature and Ryan's newfound enthusiasm for wetland boardwalks by taking us to the mangrove boardwalk at Chek Jawa, on the offshore island of Pulau Ubin. Eileen, who is not as fascinated with mangroves as Ryan and I, decided to sit this one out, but we brought Chris's niece along instead.

Singapore is not awash in natural spectacles, but Chek Jawa has become a highly popular exception. Its chief visitor feature is its extensive boardwalk, allowing strollers access to an extensive cross-section of shore ecosystems and marine life.

Nipa palm (Nypa fruticans)
Nipa palm (Nypa fruticans)
On the shore edge of the mangroves are stands of Nipa palm (Nypa fruticosa), their gigantic leaves thrusting out of the mud like enormous feather dusters (their trunks are normally underground). Here are the odd-looking flowers (source of a local alcoholic beverage) and a cluster of fruit.

Common Palmfly (Elymnias hypermnestra agina)
Chek Jawa has an extensive butterfly fauna, including some species no longer common elsewhere in Singapore. This is a Common Palmfly (Elymnias hypermnestra agina).

Malay Viscount (Tanaecia pelea pelea)
Here is a Malay Viscount (Tanaecia pelea pelea).

Common Tiger (Danaus genutia)
Common Tiger (Danaus genutia)
I was hoping that this would turn out to be one of the Chek Jawa specialties, the Black Veined Tiger (Danaus melanippus hegesippus), but I'm afraid it is the widespread (but still extremely handsome) Common Tiger (Danaus genutia).

As we set out on the boardwalk, strange structures cropped up from the mud beneath us. Are these sea anemones, their tentacles withdrawn as they wait for the returning tide? Are they, perhaps, tunicates (sea squirts), the fruiting structures of some sort of alga, or something else altogether?

Are these the mud-encrusted shells of some sort of oyster?

Well, there is certainly no question about what these are. Male fiddler crabs waving their enormous claws in display are a highlight of mangrove flats throughout the world. There are several species at Chek Jawa, and from the height of the boardwalk (and from my level of ignorance of crustacean taxonomy) I could not say which these were. I think, though, that these photos show two separate species.

As the males sat displaying near their burrows, other crabs circled near them (most, I presume, small-clawed female fiddlers checking out the talent).

This one, I thought, seemed to looking rather beseechingly up at me (though getting anthropomorphic about crabs is probably not zoologically useful).

Face-banded Sesarmine (Perisesarma indiarum)
Here is a crab that is not a fiddler: a Face-banded Sesarmine, with a electric-blue facial blaze and chunky, muscular-looking claws like a pair of boxing gloves. There are two species at Chek Jawa; I think this is Perisesarma indiarum, which is distinguished by a seond blue blaze, like an upside-down V, under the main one. You can just see that feature in the photo. Face-banded Sesarmines are largely sediment-eaters, feeding on bits of decaying mangrove leaf and other objects in the mud, and are abundant and important recycling agents in the mangrove ecosystem.

Mangrove horseshoe crab (Carcinoscopius rotundicauda)
This is not a crab, though it is called one. It is, instead, a far more interesting creature, and one of most ancient of surviving animals: a horseshoe crab, a distant relative of spiders and scorpions that has been trundling about on shallow muddy shores for over 300 million years. There are only four species in the world today, one on the shores of eastern North America and the other three in Asia. At Chek Jawa I had the singular problem of trying to decide which of two local species I was looking at. Is this a Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda) or a Coastal Horseshoe Crab (Tachypleus gigas)? I'm still not sure. The easiest way to tell them apart is he cross-sectional shape of the tail (rounded in the Coastal, triangular in the Mangrove) - hardly something I could check from my elevated position on the boardwalk. Its  rounded shape and lack of obvious large spines lining its broad rear segment suggests to me that this is a Mangrove, but I could certainly be wrong.

Blue-spotted Mudskipper (Boleophthalmus boddarti)
From Ryan's point of view (shared, no doubt, by many others) the most entertaining feature of Chek Jawa is a chance on get on close terms with a variety of mudskippers. A number of species of these goggle-eyed gobies flick themselves over the mudflats to the delight and amusement of human visitors, including small children like Ryan. This one, if I have identified it correctly, is a Blue-spotted Mudskipper (Boleophthalmus boddarti).

Dusky-gilled Mudskipper (Periophthalmus novemradiatus)
This is a Dusky-gilled Mudskipper (Periophthalmus novemradiatus).

Gold-spotted Mudskipper (Periophthalmus chrysospilos)
Gold-spotted Mudskipper (Periophthalmus chrysospilos)
Gold-spotted Mudskipper (Periophthalmus chrysospilos)
Here is the most spectacular of the lot, the Gold-spotted Mudskipper (Periophthalmus chrysospilos). It may not look any more spectacular than the others, but that is because these individuals aren't displaying.

Gold-spotted Mudskipper (Periophthalmus chrysospilos)
Gold-spotted Mudskipper (Periophthalmus chrysospilos)
Gold-spotted Mudskipper (Periophthalmus chrysospilos)
When one male strays over the border of a neighbor's mud patch, however, the stage is set for a squabble.  Owner and intruder face off side by side and head to head, raising bright orange dorsal fins and stretching them to their full extent as the tension increases.  In the bottom photo the upper mudskipper has raised the ante by elevating his second dorsal fin as well.

Gold-spotted Mudskipper (Periophthalmus chrysospilos)
Eventually the winner, banner still raised, sees the abashed loser off.

Serpent Mudskipper (Parapocryptes serperaster)
Serpent Mudskipper (Parapocryptes serperaster)
Much smaller, and less strikingly marked is the elongate little Serpent Mudskipper (Parapocryptes serperaster). It has, though, its own striking method of calling attention to itself.

Serpent Mudskipper (Parapocryptes serperaster)
Serpent Mudskipper (Parapocryptes serperaster)
Every once in a while, one of the little fishes would leap straight up out of the water. I could not see exactly what motivated this activity, but I assume that it had something to do with either territory or sex, unless it was trying to catch a flying insect (something I don't think mudskippers do).

Spot-tail Needlefish (Strongylura strongylura)
Spot-tail Needlefish (Strongylura strongylura)
Less entertaining,though equally odd-looking, were small schools of Spot-tail Needlefish (Strongylura strongylura) swimming just under the surface where the boardwalk met the open sea.

Wild Boar (Sus scrofa)
On our return from the boardwalk, this young Wild Boar (Sus scrofa) stepped out to meet us.  Boars are increasing in Singapore's reserves, and the National Parks Department has had to reassure visitors about them.  This one, though, seemed, despite everything, quite harmless.  Well, it was only a little one.

Friday, March 8, 2013

New Zealand: Wetland and Forest

 When you think of New Zealand (or, at least, when I do), your thoughts are likely to run to glacier-covered mountains, dense, dark forests or rocky coasts overlooking the sea. Freshwater wetlands are probably not the first thing that would come to mind. One of the things I discovered on our December 2011 trip around the North Island with our grandson Ryan is that not only does New Zealand have such places, they have attractions I wouldn't have suspected for a small child. It was during a rainy turn around the boardwalk at Pekapeka Wetland that Ryan looked up to me and said, happily, "Grandpa, I like being in New Zealand!"

Pekapeka, certainly, makes for a pleasant stop.  It is a restored wetland, operated by the Hawkes Bay Regional Council, 10 km south of Hastings (we stopped there en route from Mount Bruce to Napier).

The wetland boasts over 80 species of plants, both native and introduced.  This is (I believe) one of the native species, Harakeke or New Zealand Flax (Phormium tenax).

 New Zealand has a fascinating collection of endemic land snails. This, unfortunately, isn't one of them. It is, instead, an invader from Europe, the Brown Garden Snail (Cantareus aspersus), and its presence has raised concerns about its effects on native vegetation as well as on the snails that really belong on the islands.

After a bit of reluctance, Ryan got to touch the snail -- for him, one of the high points of our trip!

On our way out of Napier, we stopped for another wetland walk, this one along the Ahuriri Estuary Walkway on the edge of town.  Like Pekapeka, this area is of fairly recent origin - but this time the cause is natural.  Until 1931, this was part of a vast tidal lagoon.  The massive Hawkes Bay Earthquake in that year lifted the estuary by 2.7 metres, draining most of it.  The walkway circles what is left.  These striking sculptures, by local Maori artist Hugh Tareha, are pou whenua, wooden marking posts used to designate places of significance or tribal boundaries.  We didn't know that at the time, and found them rather puzzling!

Here we found another exotic invader: the Hottentot Fig (Carpobrotus edulis), a South African plant that has become a highly invasive pest in many parts of the world (however attractive it may be).

The Welcome Swallow (Hirundo neoxena) is another new arrival in New Zealand (it has bred in the islands only since 1958), but unlike the Garden Snail and the Hottentot Fig, it got here on its own.  

Out on the water, at some distance, Ryan and I found a few native water birds.  These little blobs represent our closest look at the endemic New Zealand Dabchick (Poliocephalus rufipectus), the smaller of New Zealand's two grebes.

This photo does scant justice to the attractive New Zealand Shoveler (Anas rhynchotis variegata), one of the handsomer ducks in the country (for proof see here).  It is considerably more strikingly marked than the only other subspecies, the Australian Shoveler (A. r. rhynchotis).

Ryan was most fascinated, though - as small boys would be - by the crabs.  Mud crabs (Helica crassa) and their burrows are abundant features of estuary life, and the crabs themselves have an ecological important role as environmental recycling units.  Anyway, Ryan thought they were pretty neat.

From Napier, we drove back across the North Island (once again, in the rain) to Hamilton and the first step on our journey back to Malaysia.  I convinced Eileen (and Ryan) to put up with a brief detour to the Pureora Forest Park west of Lake Taupo.  I was hoping to turn up one of the most interesting of New Zealand's forest birds, the Rifleman (Acanthisitta chloris), but between the rain and the time of day it was to no avail.  

Nonetheless, it gave Ryan and I a last brief taste of the rich and splendid temperate rainforests that once blanketed the island.

The most magnificent ornaments to the forest, to my eye, were the several species of tree ferns.  I think this one is a Wheki (Dicksonia squarrosa), but fern experts out there may feel differently.

Some more tree fern views: a fiddlehead, and a set of drooping fronds (which, on some species, remain as a sort of"skirt" under the living leaves).

Of course, a lot of the forest ferns were much smaller!

The humid forest floor was decorated with the minature parasols of umbrella moss (Hypnodendron spp.)...

...and lichens of various sorts.

My last New Zealand birds: Piwakawaka, the New Zealand Fantail (Rhipidura fuliginosa)...

....and the tamest of the tame, a North Island Robin (Petroica longipes), perhaps hopping out to check whether Ryan and I were merely humans, or perhaps a family group of moas stalking by, kicking up a few tasty insects as we passed.