Capturing the Diversity- combing the beaches

Counting the turtle tracks is the easy part.  The difficult part is the work needed to be done on the beach to ensure the count is accurate.  Although tracks soften quickly as the wind blows the sand around,  you need to get an accurate count each day (or maybe each week depending on the frequency of turtle nesting events) so you have to wipe the slate clean before you start the counting again.  So the same day that the count is complete, the Conservation Team and any willing volunteers head out to rake the beach.  The first time I got roped into doing this I had not intended to be involved.  I had gone for  a late afternoon walk up to Fort Bedford, but I spotted a sizeable team of rakers out on Long Beach.  I watched them for a while trawl perpendicular to the sea, up and down, up and down, and started to feel guilty, so I dropped straight down through the thorn trees and went across to greet them.  They were only half way along and some were tiring so were pleased to see some fresh legs.

The aim was not to smooth the beach down like the machines which manicure the front of every resort hotel in the Caribbean or Med.  By raking roughly across the whole beach you are breaking the existing turtle tracks up.  By the archaeological principle of superposition, if you see a turtle track over the rake marks, you know there has been a turtle there since you raked. By this method you can distinguish the old from the new and increase the accuracy of your count.

But even so, it is back breaking work, and blister making too.  I helped out on Pan Am Beach one morning.  I was keen to go as for all the years of travel there, I had never made it down on to this beach.  It was a popular weekend spot, partly as it was just below the American base, and the name Pan Am stemmed partly from it being at the end of the runway.  I went with Natasha and Jolene.  Natasha was one of the few staff at Conservation that had worked alongside me since I first visited Ascension Island; if you wanted to know where anything was  or how to do something, she was probably storing it at the back of her mind somewhere.  When others were not strict at recording data in the databases she would be there to get them sorted.  Jolene had been around Conservation for several years too but my trips always had coincided with when she was at school or on holiday.

We dropped down the cliff edge on a rough cinder track and parked up at the beach hut at the far end.  For this trip we did the counting first, then worked on the raking.  As Pan Am was not so intensively used we got away with a simpler method, raking the front of the beach only, and then messing up (I mean marking) the new nests by raking across the tracks made by the female as it left.  It saved a bit of time but it was still a long morning of work.

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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.

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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 – 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.

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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.