Giant Petrel Census

The 1^st of December marked the beginning of an all island census to ascertain the geep population in its entirety for the first time in 10 years. As a reference point BI is split into areas named according to known locations, topographical layout or inhabiting species; and these are the areas we checked systematically for the geep population.

BI areas

A small part of North Valley, the right hand side of Bottom Meadows and all of Top Meadows constitute our more regular study area where we also check nests for eggs and chicks in order to work out productivity. So these areas were already counted for population as a result.

Blue marker posts indicate nests in the geep study area

But with so much of the island not regularly monitored for geeps the full census was set to take about 10 days! So it was time to get cracking as soon as we could.

Day 1 – Al and I completed a full survey of North Valley. By walking backwards and forwards across the entire area we could record the location of every geep nest on our GPS. We actually have two GPS’s each, one for each species, and completed transects a distance apart from each other, walking in parallel, to cover the area quicker. Even so, North Valley alone took 5 hours to complete largely due to the terrain - steep slopes covered in tussock! The tussock is exhausting to climb over but it pretty much covers BI so we certainly keep fit doing this work!

The terrain of tussock and steep hills is certainly a challenge!

Day 2 – Late on the 1^st and in the morning of the 2^nd the snows came in. This made completing the Wanderer Valley area even more difficult as the snow hid pools of mud, water and rocks and made climbing over the tussock very slippery. Can’t remember how many times I fell over!! But the snow did make the views spectacular whilst surveying.

Geep in the snow

Day 3 – I completed Goldcrest Point, tackling the steep tussock, and Lucy surveyed some mollymawk colonies nearby. We then joined forces to complete the census for Bottom Meadows; when Al returned from some seal work the three of us dodged a lot of furries to complete the census around Square Pond. In all surveying took a bit over 5 hours and we certainly felt the large distance covered in that time at the end of the day!

Dodging furries can be a tricky business! But this Bird Team can do it :) (photo courtesy of Al)

Side note 1 – Geeps normally feed out to sea; however, during the summer they will just as readily scavenge carrion on the beaches, and with plenty of furries around the geeps won’t hesitate to use their powerful bill and feed on seals that have died. When they feed like this the geeps adopt a somewhat unusual pose, with their wings outstretched and tail in the air it gives them a strange almost turkey-like look!

Geeps scavenging on furry carrion

Day 4 – Al and I completed the surveys for Johnson Top and Johnson Bottom, during which we came across my first opportunity to see a white-chin up close. I had been unable to provide a photo of this species in my previous blog because they are burrow nesting; but this little guy was very accommodating in sitting outside in front of a grey-head colony. Al also surveyed Long Ridge whilst I had some work to do at base. The survey is coming along very nicely now!

A white-chin hanging out with the grey-heads

Day 5 – The fifth day was a particularly long one as I was out for 7.5 hours in total. In the morning Lucy and I surveyed Wanderer Ridge, Wanderer Ridge Extension and Cobblers Mound; in the afternoon Jerry joined me to complete Bird Sound and a couple of patches of Mt. Cwm. Having not been over to this side of the island before it was amazing to get my first views from the bottom of La Roche, BI’s biggest peak – stunning!

View from bottom of La Roche

Day 6 – I’m continuing to venture further from base (which is marked by the star on the map) and explore the ends of the island even more now in doing this census. It is fantastic to be able to see so much of the island so early in my time here; and on Sunday afternoon Al and I managed to census the majority of Mt. Cwm. During this survey I came across a geep with a bill colour that wasn't obviously green or red like most geeps; the two species can occasionally interbreed and create hybrids with bills of indeterminate colour. It turns out this one is most likely just a pale billed southern, but they do keep us on our toes with the identification!

Southern geep with a pale bill

Side note 2 – By completing a full island survey of the population we were also able to find a few ‘spirit geeps’. These are white morph southern geeps and will constitute a small proportion of the population.

'Spirit' Geeps

Day 7 – Monday was an absolutely mega day! Lucy did the census for Molly Ridge and Molly Meadows whilst Al and I did Tonk Ridge and Molly Hill. We took this route as Al had to check some equipment at the top of Tonk, a 209m peak on the island; therefore I got my first views across the whole island on a clear day – spectacular!

Views either side of Tonk - you can still see the wanals on the top view as well as the Big Mac colony!

After these areas the three of us found all the geeps on Pearson Point. My first trip to this area meant it was also my first trip to the main shag colony where we collected some pellet samples from the floor for diet analysis. These birds are really pretty and it was great to see them as they incubate their eggs.

Shag colony

Not only did we complete these areas for the census, but Al and I also did a thorough check of the whole study colony area as well in order to keep our control data up to date – monitoring a certain area regularly allows us to work out the proportion of nests that have failed at this stage of the season; therefore our counts of the other areas can be adjusted to account for any nests that have failed prior to the census. 

Day 8 – Al, Lucy and I again joined forces to complete the Gony Ridge, Dank Fen, Round How and Morris Point areas in just 4.5 hours. This meant that everything West of Mt. Cwm has now been fully checked for geeps! With just the Eastern edge of BI to go we can see the finish line.

A northern geep enjoying a swim in the ocean

Side note 3 – The two species of geep differ in their breeding cycles in that the northerns nest about a month earlier than the southerns. The northern geeps lay in late September to early October, incubate for 57-62 days and fledge after another 106-120 days. Whereas the southern geeps lay in early-mid November and take 55-66 days and 104-132 days to incubate and fledge. Both lay just one egg each year. So as these timings suggest, during our census the northern geeps have largely been on chicks (the first hatched on 21^st Nov) giving us great views of the youngsters.

Northern geeps with their chicks

Day 9 – Unfortunately, with just one day to go, the rain set in and delayed us by 24 hours. So it wasn’t until the 10^th December that Al and I surveyed Farewell Point, Mac Cwm and the last edge of Mt. Cwm; thus completing the census! The relief of getting the whole count done can certainly be felt (I walked over 70km through tussock, mud and snow - on an island that is only about 4km x 1km), but it was a privilege to be a part of this survey. Counting every nest of these magnificent species whilst getting to see the entire island, including areas that people can be here for months, or even years, and not see, was a great way to kick-off my work on BI.

View from Farewell Point looking back at South Georgia, Bird Sound (the channel) and Bird Island

I’ve got to say that I really do love these prehistoric looking birds and now with the chicks to monitor there is plenty of work still to do in the regular study areas! Time to get climbing through the tussock again!

Geep chick

NB: results of the census will be released by BAS accordingly