Posts Tagged ‘Panama’

Pelliciera comparison and Belize alert

July 5th, 2009

Having just learned how to put PowerPoint presentations on the blog, I am providing two such slide shows created by Candy Feller. The first concerns Pelliciera rhizophorae mangroves, and the second sounds the alarm re the impact of development on mangroves in Belize.

Wetland or wasteland?

June 28th, 2009

As arranged, Karl, Rosabel and I show up at the camp by the river at Juan Diaz at seven. High tide is heaving the flotsam of trash in slow rhythmic waves. The Bay of Panama should be called the Bay of Garbage. It floats down the rivers and the tide distributes it along the beaches and up into the mangroves. We walk through it up to our knees to get to the canoe, a stumpy dugout that looks in danger of capsizing even before we get in, let alone once we start across the channel.

Wetland or wasteland?

KENNEDY WARNE
Wetland or wasteland?


Viĵil paddles us to the opposite shore, where we set out to find the old crab collector. We follow a trail under the roosting trees of pelicans, cormorants, frigate birds and vultures. The undergrowth is so spattered with guano it looks like someone with a paint gun has run amok. The stench of ammonia is intense. Pelicans hoist themselves off the swaying branches and wing across the bay, rising and falling against the distant skyscrapers of downtown Panama.

We slosh through the mud, the mangrove breathing roots and the trash. We are at least a hundred metres from the shore now, but light bulbs, soft drink bottles and flip-flops lie in drifts amongst the trees. On a patch of higher ground I am surprised to find cactuses growing among the mangrove roots.

Pelicans, mangroves and the highrises of Panama City.

KENNEDY WARNE
Pelicans, mangroves and the highrises of Panama City.


Antonio finds a path that winds through tall canal grass—an introduced species that looks like ordinary grass on steroids, growing head-high on thick stalks—and we reach the crabber’s hut. Embers are smouldering under a cooking pot, but the crabber is nowhere to be seen. Viĵil and Antonio whistle and call, but there is no response. They conclude that he has gone off hunting.

It isn’t possible to wait for his return. So quickly does the tide fall on the Pacific coast that we would be stuck here until evening. Even on the way back to the canoe the sea has retreated by hundreds of metres, leaving a brown silt soup below the wrack line.

Viĵil, Rosabel and Karl negotiate the mangrove trash-heap.

KENNEDY WARNE
Viĵil, Rosabel and Karl negotiate the mangrove trash-heap.


And so ends my visit to the mangroves of Panama and my journey among the mangroves of the Americas. Seven weeks, six countries, dozens of communities visited, hundreds of people met. It seems appropriate to be finishing up in a mangrove forest that is both a cornucopia and a rubbish heap. Juan Diaz epitomises the mangrove problem: treasured by the few, trashed by the many.

I don’t see much hope for the rainforests of the sea until their true value gains wider recognition. I don’t mean just a price per hectare, but their intrinsic worth. Karl Kaufmann mentioned something that has stuck with me: the need for a new narrative about land use. It is no longer legitimate, he said, for us to think of land as private, discrete assets. “From the point of view of the earth, my plot of land isn’t separate from everyone else’s. We all have a stake in what’s left.” This is a big topic of discussion, one I have I only started to get my head around. Smarter minds than mine have written about the need for a transition from an environmental metaphor of infinite wilderness, inexhaustible and impervious to human desecration, to one of the “house of nature,” finite and vulnerable, which each resident shares with everyone else.

An unusual sight: cacti among the mangrove pneumatophores.

KENNEDY WARNE
An unusual sight: cacti among the mangrove pneumatophores.


As I see it, my task with Last Stands is to help establish and promote the intrinsic worth of mangroves, and to make connections between one resident in the house (eg the consumer of unsustainably farmed shrimp) and another (eg the cockle collector who relies on healthy mangrove stands). A shared sense of values surely leads to a shared desire to preserve. Or as Jacques Cousteau once put it: people protect what they love.

Beside the canal

June 27th, 2009

With the afternoon high tide lapping at our ankles, Rosabel’s husband Karl Kaufmann and I are poking around in a patch of mangroves in a suburb of Panama City called Diablo. It’s in the former Canal Zone, a corridor of land that extended five miles on either side of the Panama Canal and was controlled by the US until 1979. It’s a leafy neighbourhood of spacious weatherboard duplex houses that were characteristic of the zone—an entity that ended in 1999 when the canal passed to Panamanian control.

Panama's cash cow: the canal.

KENNEDY WARNE
Panama's cash cow: the canal.


Karl, who has lived in Panama for 30 years and works as data manager at the Smithsonian lab, tells an amusing story about the city being unhappy with the name Diablo and changing it to Altos de Jesus, “Jesus Heights.” But the residents objected, and signs with the new name kept disappearing, until eventually the name change was given up as a lost cause. (So it is now accurate to say that the Panama Canal lies between the devil and the deep blue sea.)

We’re in an area of boatyards, boatsheds and rickety wharves. Karl remembers seeing Pelliciera here in the past, and, sure enough, as soon as we start looking we spot the distinctive pointy leaves and star-shaped flowers. Here on the Pacific coast, the flowers of Pelliciera are much pinker than they are on the Atlantic. Candy Feller wonders if they are distinct species.

A fly discovers the nectar riches of an unopened Pelliciera flower in Diablo.

KENNEDY WARNE
A fly discovers the nectar riches of an unopened Pelliciera flower in Diablo.


There’s something special about finding a treasure like Pelliciera in a neglected backwater in a place called Diablo. It’s partly why I became interested in mangroves in the first place. They’re maligned, they’re marginalised, they’re considered uncharismatic. Documentary makers aren’t beating a path to the mangroves. Their eyes are on terrestrial rainforests and coral reefs. I’ve got nothing against those habitats, but they’ve become ecological celebrities. Mangroves are underdogs. I like the idea of showing what they’re made of.

I turn to see a container ship slipping past, leaving the canal. The canal is being expanded at the moment, with the predictable attendant loss of mangrove forest. Karl asks me a question: Is there anywhere I’ve been on this journey where mangroves are held in high esteem by a majority of people? I can’t think of any.

In the evening Karl and Rosabel take me to the visitor centre at Miraflores Locks, where we watch the electrified “mules”—vehicles on rails on each side of the locks—towing ships through the canal. “The next TV you buy may have spent some time on an old mangrove site,” he says. “Panama grew up on the edge of mangroves, but today’s city is turning its back on them in favour of golf courses and recreational areas.”

A five-billion-dollar expansion will give the canal two new flights of locks and allow larger ships to pass through.

KENNEDY WARNE
A five-billion-dollar expansion will give the canal two new flights of locks and allow larger ships to pass through.


The mangrove outlook isn’t all bad. Along with the recent protection of coastal land along the Bay of Panama, resolutions have been passed that attempt to put a price on mangrove loss. Where mangrove removal is deemed a “public necessity” the land is valued at $20,000/ha. If part of a commercial project the price goes up to $150,000/ha. If mangroves are removed illegally, the fine is $300,000/ha.

Karl sees a problem with this approach. “If you put a dollar value on mangroves it’s an incentive to sell. You’re taking a public asset—the goods and services that mangroves have provided for hundreds of years—and putting it up for grabs in a one-time sale. And it isn’t even the people who get reimbursed for the loss of the asset, it’s the government.”

The correct approach, Karl thinks, is that for every hectare of mangroves taken, a hectare should be replanted. That way the public good is perpetuated for future generations.

Canalside mangroves of Diablo.

KENNEDY WARNE
Canalside mangroves of Diablo.


Rosabel and her colleagues are working to develop a conservation strategy for the Bay of Panama protected area, which they hope will be incorporated into the management plan. They expect battles ahead. Nearly half a million hectares of land near the protected area is under consideration for mining, and a further 40,000 ha just offshore is subject to applications for the extraction of rock and sand. The protected area is going to need sharp legal teeth to fend off developers. It will be interesting to see how the city balances its commitments.

Green charcoal in Chame

June 26th, 2009

White smoke swirls around a man who is shoveling soil onto a perfect conical mound. He shovels and then pats down the black peat, working his way round the mound. The wind changes and blots him from view for a few moments, then he reappears, still shoveling and patting.

Carbonero attends a smouldering charcoal mound.

KENNEDY WARNE
Carbonero attends a smouldering charcoal mound.


He is a carbonero, a charcoal maker, and he is sealing up the ventilation holes in an earth kiln, lit just hours ago. The mound will smoulder for six days, and when it is opened the chunks of mangrove timber inside will have been transformed into charcoal.

The work is happening near a town called Chame, 50 km south-west of Panama City. In this region many rivers spill into the Pacific and the coast is thick with mangroves. The majority of people here depend on mangroves. They earn a living by cutting mangrove poles for construction or converting the timber into charcoal, and they sustain themselves by fishing and collecting shellfish from the mangrove forests.

Stack of mangrove wood prior to being covered with grass, then earth and converted to charcoal.

KENNEDY WARNE
Stack of mangrove wood prior to being covered with grass, then earth and converted to charcoal.


In 2004, Panama’s environmental authority (ANAM) became concerned about pressure on the mangrove resource. Three hundred families in the region were found to depend on mangroves for their livelihood. At least 100 charcoal kilns were in operation, each consuming 15 to 20 mangrove trees per month. Pole cutters were taking 100 trees per month.

“The forest could not support so many people cutting so much,” ANAM’s José Berdiales told me.

With financial backing from the International Tropical Timber Organisation, ANAM began a project to manage and conserve 4000 ha of mangroves in the Chame region. Some areas were placed off limits to cutting, some were slated for replanting, and some were to be used in agroforestry.

Once the mound is alight, the ventilation ports at the bottom are sealed off.

KENNEDY WARNE
Once the mound is alight, the ventilation ports at the bottom are sealed off.


Now, five years later, the project is in full swing. Near the charcoal mounds, I saw a small nursery of young mangrove seedlings. Reforestation began in 2005, and the resulting stands are already more than two metres tall.

Many of the initiatives have been implemented by Juliana Chavarria, a young ANAM staff member who explained some of the challenges to me.

“Some of the people weren’t happy to have any restrictions placed upon them,” she said. “They believe the mangroves will never end.” Juliana realized she needed to find ways to create a win-win outcome for the communities and their forests. For communities, the “win” that would have the biggest impact was more money in the pocket.

Juliana Chavarria with mangrove nursery.

KENNEDY WARNE
Juliana Chavarria with mangrove nursery.


One pilot scheme that has shown great promise has been the production and marketing of “eco-charcoal.” Ordinary charcoal sells for a pittance. Carboneros get $2 for a 35 lb sack from a distributor who on-sells the product to restaurants and other users in Panama City. Juliana negotiated with a supermarket chain and found that the same sack of charcoal would sell for $13 if it were repackaged in 8 lb lots. “Everyone benefits,” Juliana said. The carboneros get more money, the supermarket stocks a quality product and the consumer has the satisfaction of supporting a sustainable harvest.

The new product, developed with just one of the Chame communities, is about to be launched, and if successful will be rolled out to four other communities in the area.

The Chame project is Panama’s first mangrove conservation effort. But mangrove protection is by no means the norm in Panama, as the next few days would show.

Mangrove crab sellers on the road to Chame.

KENNEDY WARNE
Mangrove crab sellers on the road to Chame.

More on the snake caterpillar

June 26th, 2009

Annette Aiello, an entomologist with the Smithsonian, has provided me with the following excellent information concerning the caterpillar we found in the Pelliciera forest of Peninsula Valiente (see June 22 post).

The art of deceiving.

KENNEDY WARNE
The art of deceiving.


“My guess is that your spectacular caterpillar belongs to the moth family Sphingidae, the sphinx moths, which include the well-known ‘tomato horn worm.’ Several sphingid genera are snake mimics, and in most of the cases I’ve seen so far, it is the ventral surface of the body that is displayed to resemble a snake. You can see that in the attached photograph of a species of Hemeroplanes. The head, mostly hidden, forms the blunt nose of the snake, then behind that you see the ventral surface of the thorax with its three pairs of true legs folded against the body, and the large, dark, false eyes (that can be opened and closed with blood pressure) on the sides of the third thoracic segment.
Pholus labruscae

Pholus labruscae


“Continuing back, you see the first three pairs of false legs (prologs), which are the large black structures on the ventral surface of the abdomen. The larva is holding on to the substrate with its fourth pair of prologs. In contrast, your caterpillar presents its dorsal surface during the display. The only record I can find of a similar caterpillar is Pholus labruscae, shown figure d, plate xiii of Miles Moss (1912) publication “On the Sphingidae of Peru,” Transactions of the Zoological Society of London 20(2): 73-134. Moss describes the final stage larva as ‘Remarkably snake-like, either end appearing as the head of a snake.’ He reports that the caterpillar eats members of the grape family (Vitaceae).”

John Christy, a fiddler crab expert I met in Panama (more about his work in a later post), adds the following comment:
“Kennedy – that is an amazing (!!) caterpillar, complete with liverwort-like patterning. It would seem to be highly specialized. You may well have something new. I wonder if the pattern mimics a particular snake? A quick google search produced Liophis cobellus as a “mangrove snake” of South America. It is a colubrid and looks vaguely like the caterpillar.”

Here’s a picture of the snake John referred to. Though not restricted to mangroves, it frequents mangrove forests, feeding on frogs, geckos and fish.
liophis-cobellus

Snake in the grass

June 25th, 2009

For a lot of people, spotting a green vine snake on the road, looking for all the world like a length of discarded ribbon, wouldn’t be a big deal. But when you come from a country without snakes, it’s a “Stop the car!” moment.

Well camouflaged green vine snake.

KENNEDY WARNE
Well camouflaged green vine snake.


I was on my way to a town called Chame, about two hours south-west of Panama City, to see a community project which aims to improve livelihoods and preserve mangroves—the kind of win-win scenario that all mangrove-rich developing countries should be seeking.

With me were Rosabel Miro, director of the Panama Audubon Society, and two people from ANAM, the Autoridad Nacional del Ambiente or national environmental authority, who were running the project. We had just driven to the top of a hill with a panoramic overlook of the Chame mangroves. Or at least it would have been panoramic if low cloud hadn’t blocked much of the view.

I had missed seeing the snake on the way up (looking out the wrong window, as usual) but in between us going up and coming back down the obliging reptile returned to the warmth of the asphalt. And then it paused in the roadside grass to which it retreated, allowing me a shot of its elegant head.

Two other photo ops during the Chame journey:
1. A group of environmental volunteers holding banners and giving out posters and pamphlets on the Pan-American highway.
2. Stopping for cheese-filled empanadas and chicheme, a refreshing cold drink which is basically corn kernels floating in sweet, thickened milk.

Environmental campaigners on the Pan-American highway.

KENNEDY WARNE
Environmental campaigners on the Pan-American highway.

'Let's live with the forest' is the banner message.

KENNEDY WARNE
'Let's live with the forest' is the banner message.

Empanada and chicheme, an excellent mid-morning snack.

KENNEDY WARNE
Empanada and chicheme, an excellent mid-morning snack.

Ecologist at large

June 23rd, 2009

When I was at university, involved in the cutting-edge discipline of sponge classification, I regarded ecology as “soft” science, suited to those who lacked the intellectual molars to chew more demanding meat. Ecologists, I liked to think, were the ones Mark Twain had in mind when he wrote, “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”

Candy Feller and team exploring a new river.

KENNEDY WARNE
Candy Feller and team exploring a new river.


Now I think differently. Ecology is about getting the big picture. And today, with the extinction rate in overdrive and ecosystems in crisis, how sorely humankind needs that perspective. Candy Feller’s CV calls her an insect ecologist, but this really means she’s interested in everything that has to do with an insect’s world of interactions, which is a wide world indeed. Tracking those interactions may entail analysing the sugar content of flower nectar or making aerial surveys of mangrove deforestation as much as it involves slicing open twigs to see what’s living inside.

Candy is part of an ecological subdiscipline called biocomplexity, the study of the mechanisms—physical, chemical, biological—that determine ecosystem structure and function. She came to mangrove ecology in an unusual way. She was a scientific illustrator, and was assigned to draw the underwater component of a mangrove ecosystem. Actually to draw under water, using waterproof materials and a scuba tank.

Pelliciera reflections.

KENNEDY WARNE
Pelliciera reflections.


She found she liked mangroves. They reminded her of the rhododendron forests of her youth—the feeling of being enclosed and embraced by nature. These days Candy lives in Maryland, but at heart she’s a Carolina gal. I asked her what her favourite southern comfort food was. “Squirrel,” she said, without missing a beat. When she was little she and her brothers used to go out and shoot squirrels for breakfast. It was pretty much a no-brainer to find out she liked bluegrass music as much as I do. We swapped stories—I’d backed Emmylou Harris on a New Zealand TV show; she’d met Gid Tanner of the legendary Skillet Lickers. Then she opened up the iTunes playlist on her laptop and we spent an hour getting high and lonesome on four-part harmony.
Candy and Anne Chamberlain team up to trap tree crabs lurking in liverworts.

KENNEDY WARNE
Candy and Anne Chamberlain team up to trap tree crabs lurking in liverworts.


When she retires she says she’s going to work on a plant called Jack-in-the-pulpit, which was found recently to be pollinated by thrips. She finds that an interesting interaction—thrips are normally thought of as pests, not beneficial pollinators. “I don’t want to publish, just to know,” she says. “I like the idea of pushing my walking frame into the garden and studying wildflowers.”

Watching Candy in the field, I’m pretty sure the walking frame is a long way in the future. By midday I’m wilting in the heat, with Noel Coward’s lyrics about mad dogs and Englishmen running through my head, but Candy, mud-spattered and sweating, presses ahead with the work. She doesn’t miss much, either. Today she found a fish I had been hoping to see: the mangrove killifish, or Rivulus. It was swimming in a shallow puddle in the Pelliciera forest, darting down fiddler crab burrows when it was disturbed.

We bought the sweetest pineapples I've ever tasted from these paddlers passing our research site.

KENNEDY WARNE
We bought the sweetest pineapples I've ever tasted from these paddlers passing our research site.


Rivulus is the only known vertebrate capable of breeding without a mate. It can develop male and female sex organs and fertilise its own eggs. What’s more, it can breathe air through its skin, like a frog, and one specimen spent 66 consecutive days out of water, living in a hole in a tree. The fish’s ability to survive out of water comes in handy for Rivulus researchers, Candy said—they swap live specimens through the post.

When the field work was over for the day we explored a new river system. We passed groves of Pelliciera where the buttress roots and their reflections produced rows of diamonds at the waterline. Candy stood in the bow of the boat, surveying the forest, enthusing about the epiphytic orchids, wondering out loud why the Pelliciera on this coast seem to reach a certain height and then stop growing. The birders in the group had eyes only for trogons, toucans and other avian exotica, but I suspected that Candy’s mind was on the mangroves, pondering how they fit into the complex ecological pattern she is helping define.

When the collecting finishes, the analysing begins.

KENNEDY WARNE
When the collecting finishes, the analysing begins.


I came across a statement from the late great US writer John Updike. His goal as a writer, he said, was “to give the mundane its beautiful due.” It seems to me that this is what Candy Feller is doing for mangroves, and I admire her for it.

Ay caramba! A caterpillar that thinks it’s a snake

June 22nd, 2009

Today we found a caterpillar that belongs in the Guinness Book of Records in the “most bizarre” category. About 8 cm long and as thick as my little finger, it had a head like a snake, which it would lift up if you breathed on it. The tail end had a single Cyclops eye in the middle of it, complete with a fake eyelid that blinked.

The creature was positioned head-down on the trunk of a Pelliciera (perhaps so that a predatory bird would be attracted to the eye, the “decoy”). Pelliciera trunks here are covered with mats of tufting liverworts, which are favourite haunts of tree crabs. The trunk was bare around the caterpillar’s head, and looked to have been grazed by the animal.

I’m working on finding out what sort of moth or butterfly this magnificent beast turns into, but if it’s even half as spectacular as its larvae it must be quite a sight.*

(Click photo to see more pictures of the “snake caterpillar of Valiente.”)

Contender for the 'most bizarre' award?

KENNEDY WARNE
Contender for the 'most bizarre' award?

*UPDATE Annette Aiello, an entomologist with the Smithsonian, has provided me with the following excellent information:

“My guess is that your spectacular caterpillar belongs to the moth family Sphingidae, the sphinx moths, which include the well-known ‘tomato horn worm.’ Several sphingid genera are snake mimics, and in most of the cases I’ve seen so far, it is the ventral surface of the body that is displayed to resemble a snake. You can see that in the attached photograph of a species of Hemeroplanes. The head, mostly hidden, forms the blunt nose of the snake, then behind that you see the ventral surface of the thorax with its three pairs of true legs folded against the body, and the large, dark, false eyes (that can be opened and closed with blood pressure) on the sides of the third thoracic segment. Continuing back, you see the first three pairs of false legs (prologs), which are the large black structures on the ventral surface of the abdomen. The larva is holding on to the substrate with its fourth pair of prologs. In contrast, your caterpillar presents its dorsal surface during the display. The only record I can find of a similar caterpillar is Pholus labruscae, shown figure d, plate xiii of Miles Moss (1912) publication “On the Sphingidae of Peru,” Transactions of the Zoological Society of London 20(2): 73-134. Moss describes the final stage larva as ‘Remarkably snake-like, either end appearing as the head of a snake.’ He reports that the caterpillar eats members of the grape family (Vitaceae).”

Pholus labruscae

Pholus labruscae

Forest of flowers

June 21st, 2009

We’re off again, as Candy Feller says, “like a herd of turtles.”

Emily Dangremond (right) with Pelliciera blooms. Anne Chamberlain looks on.

KENNEDY WARNE
Emily Dangremond (right) with Pelliciera blooms. Anne Chamberlain looks on.


With us today are a couple of Smithsonian communications people, filming a documentary piece on Candy, and David Luther, a bird expert who works on the conservation of endangered species at the University of Maryland. A paper of David’s on vertebrates which rely on mangroves is about to be published in the journal Bioscience. This is good news for me, because I was hoping to find a list of mangrove-dependent creatures, and David has produced that very list—for vertebrates, at least. David says that almost half of these mangrove endemics—48 birds, 14 reptiles, 1 amphibian and 6 mammals—are endangered, many of them critically so.

One of his mangrove species is chattering in the branches as we wheelbarrow our gear to the boat: the mangrove yellow warbler, a canary-sized bird with canary-coloured plumage. The male has a rusty red head, as if it had been dipped in paprika.

Village in Peninsula Valiente.

KENNEDY WARNE
Village in Peninsula Valiente.


We weave our way through the Bocas archipelago and cross the bay to the Peninsula Valiente. The sea is silky calm and dotted with the canoes of the Ngöbe Buglé people native to this area. They are fishing, diving or just commuting; rivers and sea are the only roads in this area.

We stop at a village which looks like a film set: rough timber buildings on stilts at the water´s edge, blue smoke drifting through almond trees, jungle rising thickly behind. Half an hour further on and we come to Candy’s site: a forest which includes the mangrove species known as Pelliciera rhizophorae.

Candy Feller takes nectar from a Pelliciera flower.

KENNEDY WARNE
Candy Feller takes nectar from a Pelliciera flower.


Candy has a special affection for Pelliciera, which has one of the most restricted distributions of any mangrove. It occurs on the Pacific coast of Latin America from Costa Rica to northern Ecuador, and in just a few spots on the Caribbean coast. The trees have elegant fluted buttresses, straightish trunks and long spindle-shaped leaves. But their flowers are what set them apart. Almost all mangroves have small, unspectacular flowers—except Pelliciera, which breaks ranks by producing flamboyant, star-shaped, nectar-filled blooms. The nectar attracts hummingbirds (believed to be the main pollinator) as well as many insects. We even find tree crabs taking a dram. Pelliciera blooms year-round, but when flowering is at its peak the forest is alive with the whirring wingbeats and squeaking calls of hummingbirds. “Imagine being strafed by hummingbirds,” Candy says.

On a previous trip Candy discovered something unusual: when she shone a UV light on the flowers the nectar fluoresced. Today she wants to take nectar samples and have them analysed in a lab that specialises in fluorescence. This turns out to be too easy. The flowers produce so much nectar that she can fill a glass capillary tube in seconds—if, that is, she beats me to it. I’ve been in a sugar desert lately, and am making up for it by licking Pelliciera nectar (it has a delicate caramel flavour).

The fabulous blue morpho, with the fabulous blue hidden inside folded wings.

KENNEDY WARNE
The fabulous blue morpho, with the fabulous blue hidden inside folded wings.


I walk through the forest, scouting for flowers and for the peacock flash of blue morpho butterflies, whose seemingly random fluttering always seems to be out of camera range. For a while, the best I can achieve photographically is a morpho at rest on a mangrove leaf, when the heavenly blue is hidden, and all you see are an eye-patterned grey and black. Then I find a butterfly trapped in a golden orb spider’s web, with the spider feeding on its dead body. It seems unsporting to photograph the iconic creature’s demise, but it could be my only chance to record the wing colour, so I shoot a few frames. “Frames”—the old film terminology lingers. “Files” doesn’t have the same magic.
Blue morpho, golden orb.

KENNEDY WARNE
Blue morpho, golden orb.


We eat lunch of boiled eggs, tomatoes and bread, and are treated to the sight of a basilisk, or “Jesus Christ lizard” running across the river and up a mangrove tree. “Basilisk,” I learn, comes from the Greek for “little king,” a name bestowed by none other than Carl Linnaeus, father of taxonomy.

Candy, Emily and Anne follow a similar collecting pattern as yesterday, gathering seedlings, twigs and flowers, collecting crabs and, on this occasion, measuring the salinity of the peaty mud in which the trees are growing. I help with the fiddler crabs, whose large claw has an off-puttingly wide set of pincers at the tip. I find that their posture is worse than their pinch, and manage to collect several without being nipped.

Young basilisk, or Jesus Christ lizard.

KENNEDY WARNE
Young basilisk, or Jesus Christ lizard.


We arrive back at the lab at sunset, and though it’s been a long, hot day Candy can’t resist putting in a couple of hours in the lab, slicing into the twigs and seedlings with a knife to see what’s living inside.

In front of the main building two bat researchers have set up a mist net and are catching bats at a rate of one every couple of minutes. Just as in nature, institutions like the Smithsonian have their diurnal and nocturnal residents. We mangrovistas are winding down, thinking of gin and tonics and what’s for dinner, while the bat brigade is gearing up for a night of excitement. The main researcher thinks he may have captured a new species.

Night belongs to the bats . . . and their captors.

KENNEDY WARNE
Night belongs to the bats . . . and their captors.


I take a torch down to the boat ramp and spotlight the mangroves, watching tree crabs chomping leaves and flowers. Howler monkeys are making a racket in the jungle beyond the lab, while poison dart frogs keep up a constant chirruping. It’s a great life, and tomorrow I get to do it all over again!

The nutrient economy

June 20th, 2009

It takes an hour by speedboat from Isla Colón, where the Smithsonian research station is located, to reach Isla Popa, where Candy Feller has one of her experimental sites.

Anne Chamberlain (left) and Emily Dangremont tickle the mangrove roots for crabs on Isla Popa.

KENNEDY WARNE
Anne Chamberlain (left) and Emily Dangremont tickle the mangrove roots for crabs on Isla Popa.


Candy’s main project in Bocas is to look at how nutrients affect mangrove growth. “Nutrients are the currency of food webs,” she says. She studies how that currency moves through a mangrove ecosystem in the same way that economists study how money moves through an economy. The three major elements she’s interested in (the dollars and cents) are carbon, nitrogen and phosphorus. She compares the ratios of each element in the mangrove trees in her study plots, and also in the herbivores that eat mangroves. Those consumers include everything from tree-climbing crabs to twig-boring miners. Candy has found more than 100 species which feed on mangrove twigs alone.

Some of the associations are intricate and fascinating. For example, the exit hole of one borer may be the entrance way of the next species in the chain. One of Candy’s favourites is a nemertine worm which takes up residence in an empty beetle gallery. The worm traps its prey by everting its insides. Charming!

Candy Feller in the dwarf mangrove forest.

KENNEDY WARNE
Candy Feller in the dwarf mangrove forest.


So thoroughly do creatures use the mangrove habitat that a seedling with its leaves in the air and its roots in the water will have terrestrial borers burrowing down from the top and marine borers burrowing up from the bottom.

As well as measuring the nutrients in an undisturbed system, Candy has added nutrients in the form of fertilisers to see how the mangroves and their associated flora and fauna respond. This is an important line of research because nutrient over-enrichment is a growing problem for marine ecosystems around the world. As fertilisers run off the land and into the sea, the delicate nutrient balance of mangrove and other communities (seagrass beds, coral reefs) can be thrown into disarray.

As we step off the boat there’s a surprise: a golden orb web spider has spun a metre-diameter web at head height just to one side of our access point. I hope I don’t forget its location. The spider is close to 15 cm from leg tip to leg tip, and I don’t fancy the thought of it falling down the back of my shirt. (The spider gets its name from the fact that the silk of its web is a golden colour, not white.)

Golden orb web spider near the boat.

KENNEDY WARNE
Golden orb web spider near the boat.


At Isla Popa there is a marked difference in height between the mangroves on the shore and those inland. The shore mangroves are five or six metres tall, while those inland are a bonsai forest of dwarf trees less than a metre high. Candy has found that the shore mangroves are limited by nitrogen while the dwarf mangroves are limited by phosphorus. Adding phosphorus to the dwarf trees results in dramatic growth increases, but adding nitrogen to the shore trees has much less impact.

I head into the dwarf forest with Candy while Emily Dangremont, a graduate student from Berkeley, and Anne Chamberlain, one of Candy’s associates at the Smithsonian, work on the shoreline mangroves. Our tasks include counting seedlings (living and dead) and collecting leaves, seedlings, winkles and two sizes of crab from around the fertilised trees. These will all be physically and chemically analysed back at the lab.

Leaf scars provide an estimate of the age of the dwarf mangroves—as much as 300 years old.

KENNEDY WARNE
Leaf scars provide an estimate of the age of the dwarf mangroves—as much as 300 years old.


The dwarf mangroves (which Candy refers to affectionately as “Charlie Brown trees”) are a revelation. Candy points to the leaf scars on the branches. Each time a leaf falls, a permanent record of its existence is left on the branch. Between two and three leaves fall off per year, so the number of leaf scars gives an estimate of the age of the tree. (You can’t use the normal method of counting rings because mangroves don’t lay down rings annually, but on a more irregular basis.) Though these dwarf trees are smaller than a metre in height, it turns out they are several hundred years old. They grow in a layer of peat that is close to two metres thick, which has formed from the fine roots of generation upon generation of mangroves.

In Bimini, similar dwarf mangrove forests were denigrated as “stunted mangroves” by the Bimini Bay Resort development company, which justified its plan to destroy such stands on the grounds that they were biological rejects—losers in the game of life. Seeing these ancient forests in Bocas, collecting the crabs that nestled in their leaf bases and the molluscs that clung to their branches, underscored the crassness of the developer’s rhetoric. Who can say how much life owes its existence to these trees? And who has the right to deny it?

Further inland still, where the mangroves mudflats meet the terrestrial soils of the jungle, the mangroves are much higher—10 metres or more—and festooned with epiphytes. Bromeliads, orchids and arum lilies perch and twine on trunks that are felted with moss, liverwort and filmy fern. Candy thinks of the epiphytic community as a separate freshwater ecosystem suspended over the saltwater mangrove one. It is sustained by the high humidity and rainfall of Panama. (Bocas receives up to five metres of rainfall annually, spread throughout the year—but, luckily for us, not on the days we are in the field.) The epiphytes provide yet another level of complexity in an already complex system.

Epiphytes on the mangroves are a feature of Panama.

KENNEDY WARNE
Epiphytes on the mangroves are a feature of Panama.


I walk back to the shore mangroves to help Emily and Anne catch crabs. The most effective method is to “tickle” the algae-covered roots at the water line with your fingers, hoping to flush the crabs from their hiding places and cause them to climb up the tree. If you’re quick enough, you can grab the crab before it realises its danger and jumps into the water.

Aratus, the tree-climbing crab we’re going after, has an infuriating knack of staying on the opposite side of the branch to the side its pursuer is on. This isn’t such a problem if the branch is narrow, but on a thick trunk I sometimes circled round and round (with occasional feints in the opposite direction) and only glimpsed bits of disappearing leg or pincer as the crab kept deftly out of sight.

It’s great to be in the company of scientists again, sharing a quest for knowledge. Je ne regrette rien, but at times like this the scientific career path I set aside for journalism has the allure of the road not taken.