Capturing the Diversity – counting the turtle tracks

One of the key conservation tasks at this time of year was to record how many turtles were successfully laying on the beach.  Next morning  I joined Sam on Long Beach.  In the clear early morning light, he let his dog off the lead and we started near the turtle ponds and walked the full length of the beach.  As you went along, you looked out for turtle tracks.  The aim was to count all the tracks and divide by two and that gave you the number of the turtles beaching.  But it was a bit more complicated than that.  You had to beware of those turtles who might come up on the beach and, for whatever reason, decide not to nest that night or abandon their digging before laying any eggs; so called false crawls.  So once you got a track you had to trace where it went and if it led to a nest. So there was much tooing and froing along the beach before we were able to come to the final figure.  The fresh nests were easy to spot as the sand was rucked and often still damp.

The remains of last nights’ activity were plain to see. Some previous nests were disturbed and there were what looked like golf balls strewn over the sand.  Crabs were busily picking at them  in full view.  Because the egg laying season was coming to an end, some of the older nests had little tiny footmarks coming out of them and heading mostly for the sea.  The hatchlings were starting to emerge from nests and hundreds of tiny flippers had crossed the sand from about twenty nests the night before.  I saw one that had not made it, a little dead black body splayed in a hole.  And Sam found one poor hatchling who was still alive but had failed to muster enough strength to emerge from his egg.

P1010246

Still stuck in his eggshell

We made our count and recorded it in Sam’s notebook then headed back to the our respective breakfast tables.

Capturing the Diversity -Night walk on the beach

It was with great joy that I finally got a trip to Ascension Island in the March.  The Conservation Office was now headed up by Nicola Weber and her husband Sam.  I’d met them first when I taught a short course in GIS down at the University of Exeter campus near Falmouth, where Brendan was now a professor.  The debate about Ascension’s future had settled down somewhat, although many would say it was a stagnation rather than a settling.  There was to be no belonger status, the creation of an airport at St Helena was changing the dynamics for Ascension too.  It had meant that there were areas of the island in decline.  Fewer people were being contracted by the big companies on the island, which meant the population had dropped by about 15%.  The lack of options to be belonger or own property on island had forced several of the little entrepreneurial businesses to give up – even Tasty Tucker had shut.  The one potential bright spot on the horizon was that Ascension was being promoted as a living laboratory – a place where geologists and biologists, maybe even astronomers could come and do science, and there was a noticeable increase in supporting tourism with the arrival of more cruise ships in Clarence Bay.

Along with support from the likes of Exeter, RSPB and Kew Gardens, the Conservation Department had expanded. They now had offices and laboratory space right through their building, and one of the big elements was to construct Biodiversity Action Plans for the key species.  I was brought across to troubleshoot some problems that had been experience with the databases, which after so many years good service, were getting old and clunky, but still provided a fantastically long record of biology and could churn out useful maps and statistics.

On the first day there, Sam chatted casually about the fact he was going to conduct a turtle tour that evening.  My eyes lit up and I asked if I could come along.  He could not believe after so many visits that I had never been on one.  So I explained the timing problem.  With about half a dozen others, we turned up at Conservation with head torches with red tape over them (as they disturb the turtles less when laying),  had a brief talk about the green turtle from Sam, then took the Land Rovers down to the car park at the end of Long Beach, switching out the headlights as we pulled over the hill and on to the beach.

Sam used some night vision goggles to see if there was much activity. It was actually getting towards the tail end of the egg laying season and he didn’t expect to find more than a few each hour up there.  It didn’t take him long to spot some sand being flung in the air.  We trooped off walking along the road at the back of the beach.  Once Sam thought we were in line with the female, he led the way onto the sand.  Walking across here was difficult enough in the daytime, but with only a few dim red lights waving around you had to watch your step.  Not only were you heading up and down the sides of the green turtle nests, and they were deeper than I remember probably because many were fresh and the wind had not yet blown sand back in the depressions, but they were also soft spots in the sand as well as hard, again probably due to the excavations of the female turtles, and your foot could sink above the ankle with each step.

But eventually we got close, and we could hear the grunts of a turtle.  We appeared to have arrived just at the moment of laying; which was useful as the turtle was far less likely to be disturbed.  Turtles are very susceptible during the early stages of nesting to being spooked, causing them to turn back without digging, or leaving a half finished hole.  Once the laying starts, as long as you are quiet and careful not to get in front of her, she goes into an almost trance like state and is unlikely to stop.  Sam focused his red torch on the back end of the female and we all stood behind this so as not to disturb the turtle.  We watched her large floppy ovipositor dip into the deepest part of the hole she had dug.  Shiny white eggs came gently out the end and piled up softly in the sand.  After a few minutes the pile had probably 60-70 eggs in there; Sam was surprised as often it could be a lot more.  But she stopped there and began an incredibly delicate operation with her back flippers.  She would reach wide of the eggs, scoop up sand and gently cover the pile of eggs, sculpting a smooth shape as she did so. She repeated this operation several times, producing a tough casing within which the eggs would have some protection.  I had always wondered how eggs survived on these beaches.  I had always considered green turtles to be the clumsiest of the species.  Whereas I’d seen hawksbill nests hidden away at the beach head, greens didn’t seem to care where they laid their eggs, and I had seen several waterlogged nests in Anegada all that time back in BVI.  Many people on Ascension had said that several green turtle nests might be exposed when another turtle decides to burrow, tens of eggs flung out onto the beach with the rest of the sand.  Here at least was evidence that the nest laying was more calculated.  Maybe this nest would not survive a direct attack, but maybe the weight of another female heading further back on the beach will not crush the eggs.

The Chamber completed the turtle changed completely.  Instead of the delicate mother and sculptor she became the backhoe.  The huge front flippers were used to throw as much sand in the hole.  Now Sam told us we could take more photos and the red torch light was not so necessary and we watched for many minutes as the turtle filled in the nest.  The effort it took to do all this was clearly completely exhausting.  She huffed and puffed with every heave of those giant fins, and she had to stop several times to summon up her remaining energy.  You had to consider that this was probably one of only two times a year this female would come on to land.  She had evolved to operate efficiently in the sea, her huge carapaces protected her from her enemies down there, as well as the pressure of the water, her flippers were made for swimming not walking or digging.

But this urge to create the new generation brought them back on land year after year once they were fully mature.  We all watched with anticipation of the moment when she would complete.  It appeared the nest was covered up, but now she continued to fling buckets of sand all over the place – we had to keep jumping out of her way.  Then she lurched her shoulders forward and began to drag herself out of the nest.  Again this was no quick operation.  Being on land for a couple of hours, carrying the eggs up the beach, digging the nest, dropping them in and refilling the nest had taken its toll.  She’d take a few steps, pause, breathe and look around, then continue on again.  We left her to it.  My first green turtle egg laying.

Capturing the Diversity – Back to Turtles

Over seven years of travel to Ascension Island, you may notice that I barely mention the turtles, which was the original driving force through Brendan’s work for my connection with the islands.  Somehow, all the trips I ever did were scheduled in the second half of the year when there was not much turtle activity.  So all I tended to see was the evidence literally in the sand.  Every beach was pockmarked with old green turtle nests, unless it was washed daily by the sea, it seemed the turtles had laid their eggs in every possible location.  I did see the odd dried out crusty eggshell but very little of the wastage of turtle breeding was not scavenged by the birds and crabs.  Once my trip came not that far before Christmas and I spied a few large turtles out in the open water.  Apparently these were the males waiting for the females to arrive so they could copulate with them.  I sat on the beach in the twilight one evening and watched a male clumsily climb aboard a female; my voyeurism mostly shrouded by the breaking waves around them.  I had left the island before any females started to come up to lay their eggs, though.

So it was a bit hard to visualise what Long Beach in particular would look like with females laying. I got a bit envious of almost anyone else I talked to on the island who felt it was such a natural part of life.  Why did I keep missing this wonder?

Capturing the Diversity – The long slog back

Next goal was the top of Wig Hill and again we were clambering up and down multicoloured rocks – another noddy colony in the cliffs above us at one stage, several more booby nests.  We must have covered 40 or 50 individual nests that day as well as all the cliff monitoring and  colony counts.  But when you get down this way you make sure you do the maximum amount. It would be wasteful to have to make two trips.

From the peak of Wig Hill we could spy more noddies along the cliffs to the west.  This south coast was one of the key areas for several species; Tara told me they tried to count more from the sea when they were on their way to their Boatswainbird Island trips as some of the colonies were so well tucked in to the cliffs.

OLYMPUS DIGITAL CAMERA

A real sense of isolation

Then the time had come to return to the Land Rover.  Wig Hill had already been a climb, but ahead of us was a massif that towered three times the height, and to rub salt in the wound, we had to go down this hill first before tackling it.  We had been walking for over seven hours now, tired and footsore.  But we had to get back. So it was one foot in front of the other, no heroics, sheer stupidity to put on a spurt of speed, but just slow, slow, steady progress.

I stopped looking upwards as it would just demoralize me.  But looking back from time to time was useful.  I’d make sure I would stop before turning.  Wig Hill looked even more like a hedgehog from this angle, and I could see the western part of the Letterbox in all its glory. And each time I looked back these features were indeed getting smaller.

Stedson, a good 15 years older than the rest of us, struggled up that hill.  But he had the stamina of a pack horse and just kept a steady if slow pace.  It was clear that stop start was unhelpful – if you stopped both your mind and body told you that that was the end, and it was a tough job to tell them to start again.

Eventually we reached a col just near where our original path this morning would have taken us off the track round Cricket Valley.  Simon, Tara and myself paused there to let Stedson catch up.  I looked at Simon.  He could not say a word, he was so shattered, but he did permit himself one of those smiles of achievement .  My clothes had been drenched in sweat, and blown dry again by the wind.  It was all worth it for the recovery of the bird populations.

OLYMPUS DIGITAL CAMERA

A shattered tiredness but a sense of achievement

Capturing the Diversity – Where The Atlantic comes ashore

The next stage was to traverses one of these lava flows.  I was getting used to crossing these but this one was remarkable.  We had to climb a considerable way to get up on top of it – obviously it had been a thick coating of molten rock which had come down the mountainside at some stage.  It was relatively thin, but as I paused atop it, and looked first up and down, I was astonished to see it looked black in one direction and white in the other.  The lava field had been used as a nesting colony for hundreds, maybe thousands of years, but the birds sheltered on the uphill side of the outcrops of rock, giving them some shelter from the punishing south easterly winds.  So as you looked down, you saw all the guano from the ghost colony, looking uphill all the guano was hidden and you saw the true colour of the rock.

We were trying to make our way to South East Bay now, but again the most direct route was not the easiest, and we instead started heading north west.  I could see how much we had descended from our starting point.  I could not see the NASA site, but you could see the massive lump of earth that it sat on; and it towered above us.  While we plodded along on the surface , it did cross my mind that whatever more walking we did down here, we still had to somehow climb all the way back up there.

South East Bay is one of the most dramatic places on Ascension Island and can only really be seen in its true glory from the top of the cliffs.  From the NASA site, it appears a beautiful collection of coloured rocks and a sweeping bay of frothing water, but only from down here do you get the full impact of just how superlative the terrain is, and how dramatic the full force of the Atlantic Ocean coming into contact with the cliffs really is.

The first thing to strike me was a curious hill on the far side of the bay.  It had a steep white cliff, which had a funny little promontory of white rock sticking out the front.  The white rock was capped by a carpet of lava, this time a deep rusty red colour.  The lava coated the whole backside of a rounded hill.  The effect was to make you think you were looking at a giant white hedgehog with red spines.  It was not a surprise to hear that it was called Wig Hill.  In the centre of the bay, where it more or less turned right angles from the south coast onto the extended peninsula of the Letterbox, another lava flow, another black one, poured down into the sea.  It was obviously  relatively recent and the sea had yet to erode it back to a natural coastline; instead black rocks extended well out into the bay.  But the sea was having a good go.  Massive rolling waves came into the bay at high speed, bashed against the solid rock and sprayed up, some coming higher than the cliffs themselves.  Time after time these waves would crash in, and the spray and froth would fizz and shimmer for many seconds after the undertow had sucked the water back out of the bay.  I certainly would not want to be in a boat down there – you would be smashed to smithereens hundreds of times.  Death would be a mercy.

OLYMPUS DIGITAL CAMERA

Stedson, Simon and Tara monitoring the noddy nests on the cliffside

The main reason for coming to this cliff edge on the western side of the Letterbox was to monitor its noddy colonies.  I was still feeling a bit tender on my ribs, and I had already seen noddy nests, so I volunteered to look after their bags while Simon, Tara and Stedson went down in amongst the nests.  I got another sense of vertigo as I looked down.  Tara said – once you are down there it is not so bad, but I watched those big waves crashing below us, and did not want to chance having more mishaps.  So for about ten minutes I just sat there mesmerized by the strength and beauty of the ocean as it came ashore.

The Letterbox on The Letterbox

We were on an almost flat surface, a red billiard table of fine gravel.  Stedson pointed out a number of small depressions.  These were not some volcanic features from centuries back but in fact the result years of target practice by the military.

OLYMPUS DIGITAL CAMERA

The curious crater

I looked around nervously in case a fighter jet came screaming over the horizon.  Stedson laughed -” it’s not done now”, he said.  On the edge of the cliff we came across more military hardware, this time in the shape of three frigate birds.  They were not animals but wooden decoys and apparently the navy would sail around this side of the island and crew would shoot at them to improve their aim.  Nearby , Stedson had some of his spurges that he had planted out and he checked them as we passed.  They were kept in cages to reduce the amount of cropping any passing herbivore might attempt.  Why a rabbit would head all the way out to this desert when there were rich pickings up on the mountainside was beyond me.

The weather had turned gorgeous as the morning had progressed and as we reached a real live Royal Mail letterbox that is the end of the “Letterbox” walk for Letterbox, we dug into our sandwiches, soaked up the sun, and eased our aching feet, and in my case, my aching rib cage.

I had to sign the book in the letterbox.  The aim of these walks is to allow people to have a target; you open the box to reveal a plastic bag containing pencil and paper so you can log your achievement and read the comments from other visitors.  There is also a little rubber stamp that you can put in a tourist guide to prove you reached the destination.  Most letterboxes are simple sealed boxes or even pipes, but this one was grand.  A proper UK style rectangular shaped red post box.  Like all post-boxes they are stamped with the initials of the monarch of the time.  This one was Edward VII Rex.  Considering he only reigned for about ten years, this is a fairly rare example.  The only other one I have ever seen was in …. Georgetown here on Ascension Island too.

After lunch we ambled over to the western side of Letterbox.  The land here was no longer a billiard table as lava flows had spilled over the underlying geology. But this was the area where the most successful colonies of nesting birds on the mainland of Ascension, save for the Wideawake Fairs.  Several species together flocked together in around 6 colonies, and Tara, Simon and Stedson estimated the number of birds individually and averaged out their findings.  Mostly masked boobies were present here although a few brown boobies were also mixed in.  The rocks around were white with guano and the smell was overpowering.

Capturing the Diversity – The missed step

After we had studied the spurge, I though walking was relatively easy on this ridge, and I was able to look around me as I stepped.  Big mistake.  I was looking at Boatswainbird Island as I tucked my boot tip under a piece of rock .  I  went forward, my foot stayed behind, and I was tripped.  But it did not stop there.  I went head over heels , my hands stopped my head from getting a gash from the ground, but instead the palms were badly grazed.  It must have only lasted a couple of seconds but I felt I would never stop turning; I think I somersaulted three times.  I came to a halt when my ribcage bashed against the ground.   I looked up and saw the other three looking at me helplessly.  Stedson shouted “Are you all right?”  I shouted back “Yes”, then stood up ….and winced.  I looked at my hands covered in blood and bits of grit.  I tried to move and my rib cage shrieked back at me.  But we were miles from the car, there was no way to just call a halt, so I had to put up with the pain and walk on.  As I moved more the first pain started to ease.  It would come back a day or so later, just as I was getting ready to head off to St Helena on a rolling rocking ship.

The Letterbox looked temptingly close, but to get there we still had to drop down into a wide ravine and up the other side.  We had several individual nests to check out as we progressed.  The masked boobies were not particularly perturbed by our presence.  One or two would move away from the nest as we approached, but hung around just out of arms reach.  Some would defiantly sit on the nest and it was quite difficult to determine what was underneath.

We could not take the straight route onto Letterbox which would drop us too low and make us reach a dead end against a cliff.  The Letterbox appeared like a fortress with sheer sides even on the landward side; our approach to it would be from the north west corner, which was a considerable hike from where we were.  Eventually we did climb on top and the unevenness and raggedness of the lava fields disappeared.

Capturing the Diversity – Stedson’s Spurge

This ridge was proving to be a marker for nesting success.  Over the last few years, there seemed to have been a expansion of nesting from the Letterbox area itself up this slope  We recorded the data and moved on.  Stedson started to get more interested and wanted to show me a little gut in the ridge.  Running steeply downhill, the gut cut a gully only a few feet deep, and at first sight was scouring away at the volcanic rubble here, but through a series of terraced steps some of the smaller washed material had been trapped.  This thin grey gritty soil had become the habitat for tiny plants, more or less the only greenery around this area.  This was a type of Euphorbia, or spurge, endemic to Ascension Island.  Stedson had been instrumental in both identifying it and building up its population.  He took out some polythene bags and collected the tiny seeds.  As well as a small number of very small natural populations over this part of the island, he was trying to find where to introduce them elsewhere.  Probably the only native which ever managed to colonise the dry lowlands of Ascension where there was hardly any soil or water and oodles of scorching sunlight and drying winds, this was a tough little plant.  Other more widely spread spurges do exist on Ascension Island, but this one has a gorgeous reddy stem, with the little bulbous leaves, storing away all that precious water it needs to survive within a thick plastic like skin.  And the tiny flowers are so pretty with their little white heads.  But all on a minute scale and unless there was a large carpet colony of them, most people would never even notice they were there.

Stedson was different.  He had an eye for spotting individual plants in amongst others or the empty terrain like here, and he had built up his own knowledge of their environmental niches, so much so he could more or less predict where you might find one of his precious endemics. I remember a tour he took around one of the uppermost paths on Green Mountain, Elliot’s.  While we were happy to see the mix of vegetation at different stages of the trail, he could spot the tiny collections of endemic ferns in a rockface or on a ledge.

Capturing the Diversity – two hours in and finally some birds

As we turned the corner I got the first glimpse of Boatswainbird Island.  Too many times I have heard people refer to the Ascension Islands, as if this was an archipelago.  In actual fact it is really only one lonely island.  OK , so there are two, but Boatswainbird is really just an oversize stack, a fragment of volcanic rock which became detached from the main land and is gradually eroding back to sea level.  It has been the lifesaver of the breeding birds, though, a Noah’s Ark against the flood of cats, rats and humans.  The Conservation team travel over there at least once a year to check up on the breeding, particularly the frigates who rarely breed anywhere else.  It has sheer cliffs on four sides good for noddies but a relatively flat top perfect for thousands of other birds to nest.

Where we were heading had a similar make up – a nice flat surface that probably once was coated in bird nests.  But to get there we had to negotiate some difficult terrain.  We were still clinging to the side of White Hill, but that now dropped straight down to the sea and unless we could find a way to drop elevation we would just come full circle and be back at the Devil’s Ashpit.  A gash in the hillside opened up – you could hardly call it a valley.  It was just where when rain fell, water scoured the soft volcanic rock and had dug out a channel. But it was enough for us and we dropped down with it for  a couple of hundred metres.  It continued down over a cliff edge, but here we turned right, climbed up out of it and were on a ridge.  And after an hour of walking, we saw our first bird nests.

Contrasting sharply with the black lava, a bright white Masked Booby sat guarding a nest.  I keep writing that word but hope you have not got the wrong idea.  This nest is no picturesque collection of twigs, leaves and moss; it is not some great architectural structure that would make a stork or a weaver bird proud.  It is a small scrape in the surface of the rock, enough of a depression to stop eggs from rolling too far away.  Nest sites are obviously used time and again, as the rock might be ground down to a thin greyish soil – a little bit more of a cushion for an egg or chick than bedrock.  But what mainly marks these places is the guano all around.  I’ve always had mixed emotions about the smell of shit.  There are theories that the smell of one’s own faeces is in some way comforting and maybe animals feel less disturbed when sitting in amongst their own droppings.  But I would imagine its use was more to deter others to come near as it is so disgusting.  Creatures which rely on the sea in particular have a certain odour to them.  When I travelled through New Zealand on holiday one time, I could always tell when a seal was about by the overpowering pungency of rotten fish coming from its orifices.  And here the guano smell had a similarly acidic aroma.

Capturing the Diversity – Starting the longest walk

It was a good job that Ian did not accompany us the next day.  I’d signed up for the longest of the bird monitoring walks, to an area called Letterbox.  I am not sure it was the worst; apparently the scree run down to Spire Bay and the long steep climb back was the most challenging but it was relatively short.  At the time of this visit, the closest road to the Letterbox was at the NASA tracking station.  From here we were to make a sweep of most of the south east coast of Ascension.  We arrived as early as we could, and the day started out misty with a drizzly rain blown in from the south east.  From the car park you could just about make out most of our route, although it was obscured behind hills or down in dips in a few places.  With Tara and Simon, Stedson had come with us.  He helped out with the bird monitoring if he had to but he also wanted to check up on one of his plant restoration projects down on Letterbox itself.

OLYMPUS DIGITAL CAMERA

A good view of where we were to walk (from the NASA site) – looks easy from up here

We started just back from the NASA station opposite the Devil’s Ash Pit, a very easy track which ran along the edge of a crater called Cricket Valley, which was deep and coated with a unique ecology of dense scrubby plants.  After about five minutes we turned off onto a narrow path, and that was the end of the easy walking for the day.  This trail passed underneath White Hill and down a steep valley that would eventually drop into the ocean at Spire Beach.  There was a path here but it was one foot wide, i.e. the width of my foot.  The ground rose at a 75 degree angle above the footpath, and dropped sharply away on the other side; indeed the path itself was often at an angle.  Now I do not suffer much with vertigo but I did get a nasty giddy feeling as I went on down.  I had to control it because there was no room to sway around here.  I was glad that the mist was quite thick as it meant I could not see much of the valley below, and my hand kept touching the wall of hill to my right just to reassure me I was still upright. Stedson pointed out another path which dropped away steeply from ours – this was the route down to Spire Beach.  I saw what they meant about this being the most difficult walk and was glad in a way I didn’t have to head that way.

Our path curved around the north side of White Hill and eventually reaches much flatter land with more room to spread out.  The mist was beginning to clear and I could see down to Spire Beach below – a beautiful bay cut off on all landward sides by steep cliffs.  You could see why birds and turtles would think it safe to leave their eggs down there.