One good TERN deserves another

Happy (belated- stupid internet) Valentine’s Day from Gough Island!! Today’s blog is all about our Terns. It seemed like an apt choice, as Terns are faithful partners and will stay together for life, often returning to the same nest year on year. Although, advances in technology over recent years have uncovered all sorts of scandal that have gone unnoticed previously, both in Terns and other seabirds. If a pair fail to breed, they may well separate at the end of the breeding season, only to return to the same colony with a new partner the following spring. In some species when their partner leaves to fish or find nest material, certain individuals will take the opportunity to sneak off to a neighbour’s nest and initiate a sordid affair. Perhaps not such a happy Valentine’s after all….    

The happy couple; a pair of Antarctic Terns (David Kinchin-Smith)

Terns have been one of my favourite birds since I was small; something I inherited from my Dad. It’s really nice to have a species of Tern new to both of us here on the island, the Antarctic Tern. They are virtually identical to the Arctic Terns we have in the UK, and hearing their familiar screeching as they protect their young from predatory Skuas is a little piece of home in such a foreign place. This particular subspecies only breed on islands within the Tristan da Cunha group.

An adult Antarctic Tern in flight (David Kinchin-Smith)

Antarctic Terns are small but striking birds. With long white tail streamers, slender wings and beautifully graceful flight patterns, they can certainly hold their own in the stunning cacophony of birdlife on this wonderful island.

An adult protecting its egg (David Kinchin-Smith)

There are a lot of unanswered questions about how these Terns live their lives on Gough, but we do know that they return to the island at the start of the summer and have laid their eggs by the end of January. There seems to be quite a lot of variation in the timing of their breeding attempt. This could be because if their first clutch of eggs is eaten, they can lay another clutch and have a second attempt at producing young. Whatever the reason, after an incubation of around 24 days all of the chicks have hatched by now, and the majority have reached fledging age.

A newly hatched chick (Em Witcutt)

Just a few days old; a young Tern chick (Em Witcutt)

A fledgling ready to head out to sea (David Kinchin-Smith)

They will hang around for several weeks however, as the parents will continue to feed them while they learn to look after themselves. After this they head out to sea for the winter, migrating to the coast of South Africa, just like many of the terns I know from home. 

Protective parents... (Em Witcutt)

Em

Gough Needs Moor Bunting!

It’s not all about seabirds on Gough. I know, I’m as surprised as you! Gough is home to two endemic, and rather special land birds, the Gough Bunting and Gough Moorhen. There is still a certain amount to learn about both of these species, and I still find it incredible that they are only present on this small island in the South Atlantic (although moorhens are now found on Tristan having been introduced in the 50s). One of our jobs this season has been to establish 50 transects covering as much of the island as possible, to learn more about the populations and distribution of both species.

Adult Gough Moorhen (David Kinchin-Smith)

Adult male Gough Bunting (David Kinchin-Smith)

During the round-island count last week it was fascinating to visit areas of the island which are only walked a couple of times each year. For most of our four days, Em and I were joined by buntings; indeed we were woken each morning at Waterfall Camp by a rather vocal family. The young from this season were very evident as we walked around, as intrigued by us as we were by them. The buntings on Gough have little fear of humans having very rarely, if ever, encountered our likes before. This is a tameness which surpasses a friendly Robin in your garden; sit still for long enough on Gough and these birds will soon be hopping over your legs. But herein lies a fairly major problem. Before sealers accidentally introduced House Mice onto Gough in the 19th Century, these buntings were completely undisturbed. Having not evolved with mice on the island, the buntings have virtually no predator response and as such the population has been hit hard by egg and chick predation. There are now estimated to be fewer than 500 pairs on the island and it is thought that if the mouse eradication were not to happen we would lose the species within a decade; this would be the next extinction of a bird on a British Territory (RSPB - Gough Island Restoration Programme).

A very friendly juvenile bunting (David Kinchin-Smith)

Our alarm clock at Waterfall Camp (David Kinchin-Smith)

An intrepid mountaineer (David Kinchin-Smith)

The breeding season is over for the buntings and the birds won't be nesting again until Spring 2017 (October/November time). It was encouraging to see good numbers of juveniles in the highlands during our Tristan Albatross counts, so 2016 seems to have been a fairly successful season.

So onto our moorhens......the current population on Gough is thought to be between 4,000-5,000 pairs, and although similarly effected by the mice, the species is not in such imminent threat of extinction. However, our team medic who is on Gough for his 3rd season, says that the numbers around the base are well down compared to his first year here. Whether the distribution of the species has changed or whether the impact of the mice really is as dramatic as we fear, we cannot say for certain. But our transects should help reveal some of the unknowns for the species.

As with the buntings, the season is largely over for our moorhens. October through to December is the peak for the species, and youngsters from this year are fairly independent from adults at this point. Interestingly, Gough Moorhens may raise two broods each season, with chicks from the first helping adults to rear the second. When you leave base they are usually one of the first birds you see. And whereas a bunting may feed off the sole of your shoe, pecking at seeds and insects, if your back is turned a moorhen will feed directly from your plate. So the buntings are certainly the more well-mannered of the two.

Together, both species make Gough that much more special and remind us off what we could lose if we don't act.

A young Moorhen enjoying a sunbathe (David Kinchin-Smith)

David

Reference.

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

The Great Tristan Albatross Count (Part 2)

Our route around this wonderful island (Gough archive)

Em and I have just returned from an island-wide count of our incubating Tristan Albatrosses. One of our first jobs when we arrived in September was to do a similar count to record how many Tristan chicks had survived to fledgling age in the 2015-16 season. And we will do the same with the Gough 63 team in eight months time, to teach them the routes around the island (as we were taught) and to count the number of large Gony chicks for the 2016-17 season.

These two counts enable us to calculate an overall productivity for our Tristan Albatrosses each year and to see how different areas of the island compare with each other. We were both struck by the fairly grim realisation that three of every four nests we counted will most probably fail due to mouse predation, and it may be even higher. Yet another sobering reminder of why a successful eradication is essential to ensure the survival of this truly magnificent species. But on a more positive note, the UK government has committed £1.75 million towards the Gough Island Restoration Programme making this ambitious eradication more of a reality (Please read here: https://acap.aq/en/news/latest-news/2682-saving-albatrosses-from-mice-in-2019-the-uk-government-has-committed-1-75-million-to-support-the-gough-island-restoration-programme).

Crossing the Rowetts - right: Gonydale (David Kinchin-Smith)

And left: Albatross Plain (David Kinchin-Smith)

One of over 1000 birds we counted (David Kinchin-Smith)

Hatching in 2 months! (David Kinchin-Smith)

Returning home after 4 days (David Kinchin-Smith)

There are still a number of Gonys around that aren't nesting, and probably won't this year. However, pairs continue to court each other with wings spread wide and wailing sky-calls in a strange and wonderful dance. Dancing albatrosses........we are so privileged!

Fred Astaire & Ginger Rogers (David Kinchin-Smith)

What a chest! (David Kinchin-Smith)

David