South Georgia only has one songbird, the South Georgian Pipit, so its song should be heard throughout the entire island such is the lack of competition. Unfortunately this is not the case. Ever since humans arrived on the islands back in 1775 with their rat-infested boats, it is likely that these vermin have been present. Rats can have devastating affects on whole ecosystems, especially in those species that nest on or beneath the ground.
South Georgia was no exception to this dictum, with rats preying on both chicks and eggs. Huge areas of potentially viable nesting habitat were left barren of birds with the South Georgian Pipit completely extinct from entire peninsulas. In 2011, the South Georgia Heritage Trust invested huge sums of money into the largest rat eradication project in the world in order to return this incredible island to its former pristine self. Because of the nature of the island and the conditions, the challenge was huge. Some parts of the island are completely inaccessible except by helicopter and boat, and its not infrequent to experience 80-100 knot winds.
However, there was one factor working in the favor of the team, in that the glaciers split the island into smaller sections, providing unpassable terrain for the rats. This meant that the project could target specific peninsulas in sequence, making the project slightly more manageable, although when I say “manageable”, it should be noted that each individual section to be baited was larger than any other project of this kind to date!
The glaciers themselves provided the team with another challenge. Since they are receding at incredible rates, often greater than 1m a day, these subsections would soon no longer be divided, allowing the rats to disperse freely across the island, meaning the team was up against the clock!
Although the eradication team went through two helicopters, both torn apart by the wind, it seems that the project has been a success. Throughout the season, I have been lucky enough to hear the dulcet tones of South Georgian Pipit songs across my Maiviken Study site. It was originally thought that these could just be migrant birds passing through but the songs continued and the sightings increased until it wasn’t long before I saw the adults flying with food in their bills, suggesting that chicks were present.
My surmise was confirmed when a week later, I eventually heard the rasping calls of the begging pipit chicks. It’s amazing the distance at which these can be heard and how easy they make it to locate a nest. Armed with my camera, I took quick photo evidence before leaving the nest alone.
All bird species nesting here on the South Georgian mainland will have been negatively effected in some way by the rats and it will be interesting to see the rates at which they recover. Some of these species, such as diving petrels and storm petrels nest in burrows high up in the mountains and so recovery is hard to measure. However, both pipits and pintails nest within the tussock grass that surrounds most of our seal colonies and it is easy to see how well these guys are doing already, just one season after the eradication finished.
I have since discovered another four breeding pairs of South Georgian Pipits at the Maiviken beaches, all of which now have successful fledglings. And I can’t walk more than 20m in the tussock without seeing South Georgia Pintail ducklings running through the undergrowth!
The work is never done. Now that the invasive fauna have been wiped out work has began on the invasive flora.
To find out more about the project follow this link to the South Georgian Heritage Trust website