Mind Your Head!

If there’s one bird not to mess with on Gough, it’s the Tristan Skua. Despite being dwarfed by our larger albatross species and Giant Petrels, they are one of the most powerful predators on the island. And it’s not just the other wildlife that falls victim to the skuas; after just a few months in the South Atlantic we have been clattered on the head more than a few times by these territorial birds. This is because over the last month their eggs have been hatching and small chicks have been appearing around the island. So we can’t really blame the skuas for their attacks as they are excellent parents, simply protecting their chicks. It’s just unfortunate that a number of pairs choose to make their nests on the paths, or very close to them!

What you looking at!? (David Kinchin-Smith)

Fleeing for our lives (Em Witcutt)

Tristan Skuas are very similar in appearance and behaviour to Great Skuas (or Bonxies) back at home in the UK. They are thought of as a subspecies of the Subantarctic Skua and Falkland Skua and, fortunately, are one species which isn’t threatened out here. Gough is home to about 1000 pairs with another few hundred non-breeders which gather in groups around the island called ‘clubs’.

Our helipad is one of our busiest skua ‘clubs’ (David Kinchin-Smith)

Skuas are only really capable of incubating two eggs, which they do so by resting them on their feet. Both adults take their turn, with incubation lasting about a month. We discovered our first eggs on 1^st October. Our chicks will fledge after a couple of months of care from their parents, being fed a wide variety of Gough Island seabird delicacies. Adults employ a number of tactics to obtain this food, be it catching birds in flight during the day, walking around and listening to movement at night or even digging up burrows of our underground species. Our chicks will eventually join our skua ‘clubs’ and some birds may even remain on the island for the rest of the year - one of the few species to do so.

An incubating bird earlier this year (David Kinchin-Smith)

Just one week old (David Kinchin-Smith)

It is understandable to have mixed feelings towards Tristan Skuas after discovering their prey carcasses all over the island. However, they are the consummate survivor, devoted parents and need to feed like anything else. They are great birds and have definitely earned my respect.....and that’s not just because of the bruises on my head!

Displaying - wings raised and raucous call (David Kinchin-Smith)

David

Reference.
Ryan, P. et al. (2007) Field Guide to the Animals and Plants of Tristan da Cunha and Gough Island

'Shear' Greatness!

Much of our time over the coming weeks will be spent setting up a new study on Great Shearwaters. These were one of the birds I was most excited about when we first applied for this job. I have wanted to see a Great Shearwater for years. The vast majority breed on the islands around Tristan da Cunha. They occasionally pop up in the waters around Britain, but I’ve never managed to spot one. So when I learned that Gough is home to a million pairs, I couldn’t wait… and they certainly haven’t disappointed.

A beautifully marked Great Shearwater (David Kinchin-Smith)

One of our study birds posing for the camera (Em Witcutt)

They are in the process of laying their eggs at the moment, so tens of thousands are returning to the island every evening. Great Shearwaters nest underground in burrows, so once they have made it home they are well protected from predation and poor weather. However, when flying in from the sea, they are at risk of being predated by Skuas. To prevent this, and to keep the location of their burrows hidden from such clever adversaries, they gather in huge rafts just offshore, waiting for the cover of darkness to swoop in. As the sun sets, all of a sudden the skies are bursting with these beautiful birds, bowling past one another with inches to spare. It is one of the most impressive seabird spectacles I have ever been lucky enough to witness. 

One of the greatest seabird gatherings on earth (David Kinchin-Smith)

Home Sweet Home (David Kinchin-Smith)

While the population of Great Shearwaters is healthy, they do face threats. Similarly to many of our Albatross species, they are often drowned after diving for bait set by long-line fishing boats and being caught on the hooks. It is thought that almost every bird will have indigestible plastic in its stomach after mistaking it for food when fishing. Here on Gough they also have to contend with our killer House Mice, who have learned what easy meals seabird chicks are and take full advantage of their lack of defences. To ensure that these stunning creatures continue to flourish on these islands, we need to know as much as possible about them in order to properly protect them. This study will allow individual birds to be tracked for the next year, which will give us important information about their migration and feeding habits. It is an exciting study to be a part of, and gives us the perfect excuse to spend time with such incredible birds. This week we have been looking into their burrows with our ‘burrow-cam’ to find the birds who will be taking part, and to check on the progress of the breeding season so far. The outlook looks promising; the ground seems to be brimming with birds, and many are incubating eggs already. We’ll be keeping you updated on their progress in later posts.

Sneaking a peek with our 'burrow-cam' (Em Witcutt)

Caught on camera (Em Witcutt)

Em

not so Giant Petrels

Em and I have just returned from a trip to Low Hump on the South West side of the island. This is the home of our main study colony of Southern Giant Petrels. We’ve been visiting the colony every couple of weeks for the last few months to monitor the productivity of these nesting petrels.

As their name would suggest, Southern Giant Petrels are large. With some birds having wingspans of over 2m and big males weighing over 5kg, they are like stocky albatrosses. The bill must be one of the most impressive in the seabird world, as I hope the image below conveys.

What a bill! And eye! (David Kinchin-Smith)

Our adults returned to Gough in August. At Low Hump the birds nest amongst grassy tussocks, and often under bogferns and Phylica trees to shelter from the elements. The first eggs were discovered early in September and our first chicks towards the end of October. Incubation is shared by both adults and lasts around 8-9 weeks; shifts can sometimes be up to 10 days!

It’s a long walk to Low Hump, but we must visit fairly frequently in order to record both partners of a pair on the nest. Every adult is uniquely marked with a numbered ring, allowing us to identify individuals from year to year.

Rewarded with stunning views.....(David Kinchin-Smith)

.....and birds (David Kinchin-Smith) 

Almost all the eggs have now hatched in our study colony and our chicks will remain with us until around April when they fledge. Our nest checks this time brought the rather unusual sight of an adult brooding two chicks where previously there had been one. All we can think is that a chick from a nearby nest had been abandoned and has now been adopted by the super parent from nest 37!

Where there had previously been one..... (David Kinchin-Smith)

A larger chick, no longer brooded (David Kinchin-Smith)

Gough is likened to Jurassic Park, and our Giant Petrels certainly support that comparison. Ryan et al. (2007) describes the birds often having “fierce physical contests over food” where they may “charge with wings spread, neck and chin feathers raised and tail cocked and fanned to look as intimidating as possible”. For me, this behaviour combined with their remarkable rumbling call makes them Gough’s dinosaurs.

Southern Giant Petrels are another species that fall foul to long line fisheries, and are listed as Vulnerable because of it. They are an incredible, prehistoric seabird that we must protect; not to mention excellent parents!

Very attentive parents (David Kinchin-Smith)

David

Reference.

Ryan, P. et al. (2007) Field Guide to the Animals and Plants of Tristan da Cunha and Gough Island

Rock-a-Bye Baby

Gough’s Rockhoppers have been busy incubating for the last month or so, and now their eggs are beginning to hatch. A few days ago we discovered our first chicks and now the beaches are a’rocking with the cheeps of many little penguins!

Welcome to Gough Little Rockhopper! (David Kinchin-Smith)

So before some more very photogenic Rockhoppers (especially for my Mum), here’s a bit of penguin science for you......

The Tristan Group holds more than 90% of the global population of Northern Rockhoppers, with Gough being home to between 30,000-80,000 pairs. In 1984 the island boasted a population of 144,000 pairs, and it is quite concerning that the reason for this decline is largely unknown. As such the species is listed as Vulnerable. Adults are instantly recognisable by their lavish golden plumes, which protrude rather comically from above their eyes; these are longer than those on the closely related Southern Rockhopper. But what the chicks lack in eyebrow they certainly make up for in cute-factor. Adults stand just tall enough to be able to peck you above your wellington boot, so from the picture you can get an idea of just how very small our chicks are!

Truly magnificent eyebrows! (David Kinchin-Smith)

Rockhoppers return to Gough each year towards the end of the winter (late July/August time). As is quite often the case in seabirds, these penguins generally retain the same mate from year to year. The nest is a relatively simple, shallow scrape created by the female, which she then decorates with small sticks and stones brought by the male. She lays two eggs, and perhaps rather unusually, the first egg is often smaller than the second. It is incredibly rare for Rockhoppers to raise two chicks; the larger b-egg hatches first, giving this chick an advantage over the other in obtaining most of the food. The chick from the a-egg simply cannot compete with its larger sibling. We discovered our first eggs in early October and now chicks are appearing everywhere!

Incubating and inquisitive (David Kinchin-Smith)

Incubation is shared between adults, with each taking it in turns to head out to sea and feed. Small chicks are then brooded solely by the male, with the female returning with feeds for the little hungry mouths. However, the poor male remains unfed for his three to four week careful guard and is very ready for the female to take over after this stint. He then heads out to sea to feed up whilst the larger chicks form crèches and are fed by the females for a further week. Our chicks will be fledging towards the end of December and into January so we will update you on their progress nearer that time.

David

Reference.

Ryan, P. et al. (2007) Field Guide to the Animals and Plants of Tristan da Cunha and Gough Island

Pairing up at the start of the season (David Kinchin-Smith)

Some of our nesting Seal Beach birds (David Kinchin-Smith)

An adult enjoying a well-earned nap.....(David Kinchin-Smith)

.....and apparently so is this chick (David Kinchin-Smith)

Remember, Remember, the eggs of November...

As seabird fieldworkers, one of the questions we are asked most often is ‘How do you count the birds?’ It certainly isn’t an easy task, and it’s one that we have been spending a lot of time on recently. This week we finally finished our incubation counts for Atlantic Yellow-Nosed Albatrosses, Sooty Albatrosses and Northern Rockhopper Penguins. For each species, we have to work out how many pairs of birds are incubating eggs within a number of study areas. This is a huge undertaking, but is worthwhile as it helps us to understand any long-term changes in behaviour or population sizes. Each species came with its own challenges. The Penguins huddle together in huge groups and nip at our legs as we walk through, and trying to find a Sooty Albatross nest through thick fog is nigh on impossible! Not that we're complaining; it was a lot of fun and gave us a great excuse to explore new parts of the island.

We finished just in time; the Penguin eggs will be hatching any day now so we’ll be back out in the colonies counting chicks very soon. We’ll then leave them in peace until they are almost ready to fledge, when we’ll go back to count how many have made it through this most vulnerable stage of their lives. By comparing all of these numbers, we will know how successful this year’s breeding season has been for each of the 3 species. 

Room with a view; a particularly imposing Molly nest (David Kinchin-Smith)

Hunting Sooty Albatross nests up in the hills (David Kinchin-Smith)

Sooty Albatrosses also nest on coastal cliffs (Em Witcutt)

Not ideal counting conditions! (Em Witcutt)

Sooty Albatrosses blend into their rocky background very well... (Em Witcutt)

How many Penguins can you see? (David Kinchin-Smith)

Standing out from the crowd... a semi-leucistic Rockhopper Penguin (Em Witcutt)

Em