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.

Capturing the Diversity – Time for a fag

We continued our walk and covered maybe a hundred individual nests and counted the colonies on at least seven stacks.  We were so busy in amongst the cliffs and the lava field that I barely looked up to see our progress.  When I did the BBC transmitters still seemed to be the same distance away, but then I triangulated with the gold balls behind us and estimated we were about two thirds of the  way along.   At last I could see the large oil storage tanks that was our final destination.  It still took a good half hour to reach them.  There was no footpath, you just had to pick your way from rock to rock, and try not to trip up or get your ankle twisted in any holes you came across.

As we kept on stepping close to the cliffs and stacks to do the monitoring, I was grateful I did not yet have the knowledge that Ascension Island is shaped like a mushroom. Underwater surveys have revealed that the waves and water have eroded away significant amounts of the submarine rock, and that large chunks of the cliff are overhangs into the ocean.  Well most of it has lasted a few hundred years, I expect another couple of hundred won’t hurt, but Ascension may end up with a lot more stacks in future, although the older ones wash into the sea, and some of the island’s precious infrastructure could either get isolated, or tumble in to the sea when the rock breaks.

I caught up with Simon, Anselmo and Ray just as they reached the gravel surface of the little car park at the end of the track.  I looked back, and could see Ian struggling on behind.  It was a good ten minutes before he finally reached us, lobster red face and barely able to breathe, let alone talk.  Ray grinned at him and released the pipe from the water bottle stored in his backpack and Ian took as big a suck as he could muster.  Then he had a cigarette.  We all laughed so hard and Ian grinned from behind the smoke, “Not doing that again, no way” he wheezed.

Capturing the Diversity – How to monitor the bird nests

It took quite a while before we reached the first birds and they were situated on the first of a series of small stacks along the coast.  Again it was impossible to count every egg and chick, but they monitor using binoculars and count the adult birds.  But nearby, we started coming in to contact with the first birds who were nesting on the mainland.  The species here are black and brown noddies, some boobies and a few tropic birds.  Counting the noddy nests was a bit precarious as they do prefer cliffside perches, but the others tended to nest on the flatter ground.  To be accurate that the right nests are being properly monitored, numbered metal pegs were left at the nest site.  A database had been created by RSPB  that allowed the team to print out the records for the walk they were doing.  This would tell them where there were existing nests (with the numbers of the pegs they left there) that needed to be monitored again.  The job was to find these nests again; usually the team could remember roughly where they were but they also had the GPS coordinates in case they needed guidance.  The tags  meant that you could keep track of which nest you were looking at and work out the sequence.  Then they just had to update the sheet with the new status (number of eggs, chicks, fledglings or abandoned nests).  If the nest is empty the peg is removed, cleaned and used again somewhere else.  This did sometimes cause some problems for the database as peg numbers could get confused and give the wrong data on the printed out monitoring sheets.  One of my jobs was to clean up the mess in the database and help make the system more foolproof.  If a new nest was spotted on the walk then more details had to be captured; the location and the species of bird as well as the nesting status.  And the new peg number.

It was all rather complicated but did help to calculate the nesting success of different species.  It took some time for Edsel and myself to get our heads around how this could be used in GIS.  Yes, we could show the current status of nesting on the islands, but what was more important was that we needed to help them show where some species were getting more successes than failures, and any progression of nesting further and further on to the mainland or in new locations around the coast. Fortunately, the way the database was set up, you could slice and dice it whichever way you wanted, an Edsel had written a canny programme to automatically draw the results of these filters and label them uniquely.  In this way, monthly maps of nest status could be shown, different coloured dots for different species and the labels showing the status, and another map could show in a period how many nesting successes and failures there had been in each area.  Tara, when she did her studies quite successfully showed how the birds were gaining in their nesting confidence and moving further and further away from those refuge stacks they had once relied on to maintain the populations in the islands.

Capturing the Diversity – Starting round the cliff tops

The other bird monitoring walks were nowhere near as easy as that one with the Cripps.  On my first trip, after Edsel had already left with his frozen fish for Nashville, and I was waiting for the RMS to arrive, I set off with a large number of the Conservation officers.  Tara and Anselmo were leaving the island while Tara took up some studies, and a local househusband called Simon was going to temporarily look after the shop.  Tara wanted to give him as much awareness raising and training as she could.  Although a volunteer already, he had to learn the walks and get to know the staff. I liked Simon enormously, a hell of a nice bloke and very conscientious that taking over from Tara, even just to caretake, would be a big job.  So he joined us on this walk, along with Ray and even Ian,  another househusband (his wife was the midwife on the island)  who generally enjoyed a few days working just looking after the office side, had been persuaded to come along.

Tara dropped us off at the golf balls on Pyramid Point not far from Comfortless Cove.  These are secret listening devices.  So secret that they are painted bright white, stand out on a promontory on the west coast and most people navigate by them if they are walking in the area.  So it was hardly hidden away.

As I stared out along the coast we were to traverse, I could see our destination – the cluster of aerials that were the BBC transmitters dominated this part of the island, and we were to be picked up in a car park just beyond them.  But our route had no set footpath, only the conservationists regularly tromped through this area.  I soon saw why.  There are no mountains here, this is another outlet of the lava flow, but the lava is very recent and the sea has managed only to cut into the rock where the tide currently reaches.  So the cliffs are severe, but like all these coastlines, where there was soft rock, the waves had cut away deeper.  The resulting coast was very incised, and birds, still fearful of predators, would prefer their nests to be at the end of spiky promontories and cliff edges rather than next to a nice footpath.  We had to weave in and out between these peninsulas and around the deeply incised coves.  As I later discovered, the gradual erosion of the lava was not always from top down, the waves were niggling away at weaknesses as sea level, below the cliffs, wearing away the rock to form deep caves, or just rushing in to all the gaps in the existing fissures.  From a distance the shoreline looked low and benign, but as you got into the twists and turns of our route, your realised just how dramatic the coastline was.  We turned one corner to be confronted by a beautiful curved arch of lava, like a totally black rainbow.  More rubbly lava overlaid this arched entrance to a watery cave.  Only when I saw one of my colleagues walking over the top, I saw how dwarfed he was by this structure.

In another place we were weaving our way inland. I followed Ray and Anselmo who knew the route well, but wondered why we were coming in so far.  Then I saw the land to my left dropped steeply down and at the bottom, there was the sea crashing in and out.  In another place I spotted an almost perfectly square swimming baths in amongst the bedrock.  I would never have swum in it – with each rock of the waves it would almost empty then refill in a matter of seconds.  In another location, I saw again that Ray and Anselmo were heading inland.  I followed on, with another deep jagged valley of rock below me to the left, and then a high cliff of lava that appeared a hundred feet higher than where I was.  I looked up and saw Ray and Anselmo above me heading back towards the coast.

We moved at different paces.  I was so in awe of the landscape I went quite slowly, Anselmo and Ray were leaping ahead as they knew they had so many nests to find in the next three hours.  Simon attempted to keep up with them, behind me Ian was wheezing away.  Ian was a slim built Geordie who loved his fags.

Capturing the Diversity – Dampier’s Drip

Before desalination, this must have been the supply for all the barracks and residences, stores and everything.  Rain did happen on Ascension, but apart from on Green Mountain it was very rare.  We truly were on a desert island.  The water catchments too, were not the first solution to gathering water.  When Ash and I had come down the mountainside from our rat monitoring walks, I mentioned to him that one location I had never been to was Dampier’s Drip.  It was only a short detour from our route back to Georgetown, a small track broke off at one of the final hairpins as you descend and took us to a shady tree glade hard up against where Green Mountains steep sides meet the lower plains.  William Dampier was one of Britain’s most famous explorers at the turn of the 18th Century, and circumnavigated the globe.  His name adorns many placenames from South America to Australasia.  He had to abandon his ship, the Roebuck, in Ascension Island off Clarence Bay in 1701 and was marooned on the island for five weeks till another passing ship was able to pick him up.  He must have thought what a godforsaken island Ascension was – the harsh volcanic landscape would have been much more stark than now – most of the vegetation we see today has been introduced since those days.  The crew’s prime concern must have been to get some freshwater, and they must have searched long and hard before locating this little cliff.  If you look up you might see that although it can hardly be described as a valley, there is a definite V shape, with outcrops of very soft lava cliffs worn into caves and hollows,  and the water from the rainfall and clouds up on top could come down to this point.  It became a place where water collection was common place and there are still old tanks there.  Old shards of bottles have been collected up, quite perversely perhaps.

The tale of Dampier finding this crucial water source has passed into island legend and his name is attached to this location.  A wonderful tale of survival in the wilds, except for one big detail.  If you follow Dampier’s very accurate description of the route you need to take to find his water source, it takes you to the other side of the ridge and into Breakneck Valley.  It makes more sense that a reliable water source is over the south east side of the island where the wind tends to blow from (and the water catchments were situated).  But obviously someone thought that this Dampier’s Drip gave enough supply to build the tanks.

Capturing the Diversity – 2/3 the power of the island

As we walked back, I was staring right into the eastern array of the World Service transmitters.  Five huge Faraday cages supported a network of wires from which the BBC World Service pumped out its content over the Short Wave.  Peter Gillies, the manager of the power station, had given Edsel and myself a tour of the facilities earlier on our first trip in return for us talking to him about mapping all the amenities on the island.  This oil fired station at the time created most of the electricity on the whole island, save for a few smaller generators at the airfield and US Base, and the small wind farm near Travellers Hill.  Of all the electricity generated by the power station, up to 70 % went into powering the BBC transmitters.  I was gobsmacked by the sheer quantity of power throbbing through those wires.  The position of Ascension slap, bang in the centre of the ocean meant it could beam radio to both western Africa and South America.  Originally it would use tapes of programmes shipped down from London, nowadays the live World Service feed is directly downloaded through a satellite dish near the power station and broadcast out through the transmitters.  A big chunk of the power stations other use was to produce desalinated water for most of the island.  Peter showed us the drawings of the electricity poles and the water pipes, and in the centre of Georgetown and Two Boats we got maps of where the streetlights were and the sewage pipes leading to the small treatment plant next to Long Beach.

He also dug out some very old maps of Ascension Island.  I loved these as it showed how different elements of the island had changed.  One map, barely 100 years past, showed that the roads went different routes to get across the island – and I wondered why they had been abandoned.  I also saw the pipeline that came down from the water catchments.  Ash and I had walked past these catchments on our route around the Bishop’s Path.  Large concrete surfaces had been pasted onto the south east facing  mountain side to catch the prevailing  rain and cloud mist that were often covering this area.  The water was channelled down to small hole at the bottom, and from this a pipe connected under the ridge, through a series of holding tanks where the flow could be controlled a lot better; and then dropped past Two Boats to Georgetown and the main storage tank opposite the church.

Capturing the Diversity – a surprise in the water

I was OK.  I used the time to work with conservation.  I say work, for much of the time, I just joined in with their activities like the cat scat monitoring and the bird monitoring.  Graham and Margaret asked if I wanted to join them on a short walk along the north east coast to monitor some noddies.  They picked me up from the Obsidian early on the Sunday morning and we drove the few miles up round the back of Georgetown and north to English Bay.  Just before the power station we turned right and parked next to the BBC’s old beach hut, the Klinka Klub.  The walk to the nesting area was only about half a mile as the booby flies, but with difficult terrain and lots of little bays and humps to negotiate, it took us nearly an hour to get there.  There are a series of small sandy beaches tucked in amongst the end of the lava flow here, as well as a couple of gravelly ones.  While it is dangerous to swim out in the sea here, they do make for more secluded picnics than the popular beaches at Comfortless Cove and English Bay.  They are also some of the more popular Green Turtle nests.

It was the first and only time I walked over the most northerly part of Ascension Island.  From the coastline, where the sea had cut little cliffs out of the lava flows, you could see the gentle sweep of the flow right back up to their source from the central volcanoes.  Those peaks were red scoria cones which glinted in the sunlight in stark contrast to the white and black of the lava.  And then Green Mountain, fat side on, towered above us.

Graham and Margaret were fantastic company; Graham with his job was well respected on island, and one of the right hand men to the Administrator.  He had been very interested in the GIS work Edsel and  I had been doing.  He said he had little need of our skills, but we did find him helpful in passing an eye over some policy statements we had to complete on data sharing and he had a wonderfully dry sense of humour which balanced his sober legal standing.  Margaret, over there as a partner to a government employee, did not need, indeed was discouraged from doing paid work, but she threw herself in to a series of voluntary activities.  They had a lovely daughter who had been with them over the summer holidays, but schooling for teenagers on Ascension was limiting, and like many, she boarded back in the UK.

Graham stopped on a small clifftop overlooking a bay full of rock pools and jagged outcrops of lava.  He pointed across the way and I could just make out that there was more guano on the black rocks there.  This was the small noddy colony we had come to monitor.  We dropped down carefully into the bay itself and made our way a little closer.  Being tight against the cliff it was difficult to access the nests directly.  There were only a few nests to look at and the best technique was to use their binoculars and watch a single nest for a few minutes.  The birds usually shuffled about and if there were chicks in there they would usually make themselves visible to you at some stage as they were often fidgety in the daytime.  You knew there were eggs too if you saw the noddies resting in a certain way, although it was probably impossible to determine how many – a lot of this monitoring had to be best guesswork.

The monitoring results recorded on the sheets, we started to backtrack.  Graham, generally a very quietly spoken man, almost shouted “look there” and pointed to a shallow rock pool only a few metres away.  Tucked along the length of one side, beneath and overhanging piece of lava, was a spotted moray eel.  Normally you only get to see the heads of these when you are swimming or snorkelling, the rest of the body has been carefully reversed into a long hole to protect it from any predators or other aggressive eels.  This one had been somewhat caught out by a retreating tide and had taken refuge as best it could here tucked as far in against the rocks as it could manage.  It gave a marvellous opportunity to appreciate the intricate markings all along its trunk.

Capturing the Diversity – Counting Birds -while waiting for a plane

Over the years, I went on several of the bird monitoring walks that the conservation group had to do.  The RSPB programme was intense; because apart from the wideawakes,the number of birds was so low, almost every nest was being counted regularly.  They not only looked for evidence of nesting, but needed somehow to monitor the progress and success rate of the laying.  Over a period of 6-12 weeks, dependent on the species, they would have to visit the same nest 3 to 5 times. Where a new pair had set up a nest, they looked first for evidence of eggs, then the chicks at various stages of development, up to the point where they get their flight feathers and fledge (i.e. fly away).  This sounds like a simple progression to monitor, but the reality was much more complicated.  The species monitored might have up to three chicks at different stages of development, some eggs may never hatch and the nests were still susceptible to predation by rats and frigate birds, or the chicks would die because of some clumsy accident or neglect from the parents.  Evidence of seeing a fledgling one time and an empty nest the next was generally seen as a success, but almost any other combination of results – empty nests too early in the cycle, or evidence that a second egg laying has happened (by the same pair or another pair of parents) were all counted as failures.

OLYMPUS DIGITAL CAMERA

Graham and Margaret – Third and fourth from right – with the other Conservation team members – 2005

Almost all the nests were on secluded coastlines a tough walk away from any vehicular access.  So the effort to monitor the birds was immense, and the conservation staff were few and pressed into many other activities.  Fortunately, there were a merry band of volunteers who also helped out at the Conservation Office.  Two of my favourites from all the trips were the Cripps family.  Graham was the Legal Secretary for the Government and had an office just along the corridor from the Conservation Office.  His wife, Margaret, was a keen volunteer for Conservation and helped out on tours, at the little display room and shop, and on the bird monitoring side.  On my way back from St Helena on the first trip, I was delayed several days.  On arrival on the RMS, I had already been expecting three days wait for the next plane home.  The schedules were not synchronized in any way and you had to build that in.  But worse was to come.  I was totally phlegmatic about the air bridge having been delayed nearly two days on the way down.  My fellow passengers from the RMS were not so relaxed.  They were mostly billeted in the Obsidian Hotel with me, and even if I did not eat at the restaurant every night, I would usually end up there for a sundowner at the Anchor Inn there.  Most had rushed round the island trying to pack in all the sights while they had the three days, and were pretty much ready to board the flight and head to the UK.  The rumours came in on the second day we were there that the southbound flight to the Falklands had not come in that morning.  More rumours started circulating that the jumbo jet had been involved in an accident on the apron at Brize Norton.  Someone driving the air stairs up to the door had missed and driven into the fuselage, making a hole right through it.  The jumbo would be out of action for over a week while it was repaired.

Calculations started going on in my head – I had been away already for over six weeks, one of my longer work trips.  The Obsidian Hotel was the best place to get the most up to date picture, although you realised mostly they were getting it from the same rumour mill as everyone else, just more efficiently.  They told us that an RAF Tri-Star was being laid on to do the route, but it still had to go all the way to the Falklands and back before picking us up for the UK leg.  That added another four days to our stay in Georgetown.