Above picture: Welcoming the new season in front of Crawford Bay on Marion Island’s south-east coast. From left “birders” (ornithological researchers) Chris Jones, Mpumelelo Mabutyana, Michelle Risi and Kyle Maurer get airborne on their August ‘Round-Island’; photograph from Michelle Risi
As seabird biologists living on Marion Island, our workload is determined by the number of breeding birds present at any given time of the year. Winter is relatively quiet with regular monitoring checks of Wandering Albatross nests, as chicks need nearly a full year to grow before fledging. These checks bring moments of joy, as we watch chicks flap their wings to strengthen their flight muscles or soak up all the attention from mom or dad during a feeding visit. However, they are also marred by moments of great sadness when mouse wounds are seen on chicks or when we need to recover a metal band from a chick carcass that has succumbed to mouse wounds and will never be resighted as a breeding adult. The seasons are changing, and spring is a time of hope as it brings with it a new season of breeders and the aspiration that Marion comes closer to a time when there will no longer be House Mice present to prey upon on the island’s seabirds.
As our days become longer and slightly sunnier, we are kept increasingly busy. The first arrival of the summer breeders is the Northern Giant Petrel (NGP). Their first eggs appear at the beginning of August. They like to breed on the leeward side of rocky outcrops, so searching for nests becomes the ultimate Easter egg hunt. These birds are fierce predators but while on the nest they are gentle giants and a pleasure to work with. We never tire of adults attempting to brood our hands as we try to read their colour leg bands. We have three monitoring colonies that we regularly visit throughout their breeding season from laying in August right through to fledging in February.
At the start of September, we will be venturing out on a ‘Round-Island’ count of NGP nests, a great activity that certainly adds lots of mileage along the whole coastline to our legs as we zig-zag between the many, many rocky outcrops searching for nests and recording their coordinates on our hand-held GPS units, while checking the birds for metal and colour bands. We will end up with a whole-island count for the number of NGPs breeding this 2023/24 season, that will be compared with previous seasons to enable us to ascertain trends. NGPs also have no respite from mice as, when we were last on Marion in 2017, we observed the first definite mouse wound on a breeding adult, something which was unfortunately observed again at a higher incidence rate last season.
Other events to look forward to are the return of the Grey-headed Albatrosses to the island’s southern coast. During our August ‘Round-Island’ we spotted a handful of adults flying about the coastal cliffs and at least one adult that had landed on Grey-headed Albatross Ridge to begin refurbishing its nest. The Ridge must be the most magical place on the island (we are a little biased though as we get to spend a lot of time there, staying in the nearby field hut) but nothing can compare to a completely full ridge buzzing with thousands of albatrosses flying overhead and reuniting on their nests down below. So, it’s safe to say that summer is on its way, but for now, we are just trying to soak in and enjoy the island and its birds as much as we can, as we leap into spring!
Michelle Risi, 80th Marion Island Overwintering Team, Marine Apex Predator Research Unit, Nelson Mandela University, South Africa, 05 September 2023
The Mouse-Free Marion Project is a registered non-profit company (No. 2020/922433/08) in South Africa, established to eradicate the invasive albatross-killing mice on Marion Island in the Southern Ocean. The project was initiated by BirdLife South Africa and the South African Department of Forestry, Fisheries and the Environment. Upon successful completion, the project will restore the critical breeding habitat of over two million seabirds, many globally threatened, and improve the island’s resilience to a warming climate. For more information or to support the project please visit mousefreemarion.org.