Tracking the secret life of snow petrels
Tracking the secret life of snow petrels
Australian Antarctic Division Ecologist, Dr Colin Southwell:
The Southern Ocean is changing, it’s changing due to a number of impacts, past fisheries, current fisheries, climate change, tourism. We want to try and understand some of the changes that are happening in the ecosystem, but it’s very difficult to do but very few of the species we have access to, to measure and monitor. Seabirds are a bit different in that they come to land to breed, and when they are on land, researchers can access them and we can study them.
We have been studying both penguins, both Adelie penguins and Emperor penguins over the last couple of decades. We will be extending that to flying seabirds as well and in particular we will be focusing on the snow petrel.
We know very little about snow petrels at present and that goes for most species of seabirds. They come to land to breed in October, they stay through the summer months, until about April, and in winter they will be foraging out in the ocean. We don’t know where they forage, we don’t know what they are foraging on during that time.
The research program that we will be doing on the snow petrels this summer will have a number of aspects. We will be doing a population survey on the islands off the Mawson area and that will be the first survey that’s been done, we will be using that as a baseline for future monitoring of populations. We’ve started monitoring breeding success of Béchervaise Island, the number of chicks that are produced each year and we will be extending that this year. We want to collect some samples of guano and feathers, so we can use those samples to infer what they are eating. And we are going to be attaching very small geo-locators which track where they are foraging when they move away from their foraging sites at Mawson, and Davis and Casey.
Snow petrels are very small birds, they weight about 500 grams. So we need to make sure any instruments we place on them are very small and don’t disturb them. The geo-locators are about the size of a 5 cent coin, they weigh about 1.5 grams. We put them on their legs, attached to a leg band. What they do is when the bird is flying they record information on the ambient light levels and the time and from that we can infer generally their location by latitude and longitude.
This research will help us understand the broader scale changes that are happening in the Southern Ocean. Through the fact that we are studying a suite of species, so the snow petrel is one species that we are studying, we are also studying the Adelie penguin and the emperor penguin. And what we are trying to achieve is a suite of ice dependent species. These species will tell us particularly what’s happening in relation to changes in sea ice in the long term.
Australian Antarctic Division scientists will add a new dimension to Antarctic seabird research this summer, deploying trackers on Antarctic snow petrels.
Very little is known about where the small white snow petrels forage and how they survive outside the breeding season.
Antarctic Division Ecologist, Dr Colin Southwell, said researchers will attach tracking devices to snow petrels at Australia’s Casey, Davis and Mawson stations.
“The trackers will be attached to bands around the petrels’ legs while they are at their breeding colonies and will log the birds’ positions over the next ten months,” Dr Southwell said.
“This information will tell us where the birds go and which marine habitats they use during the long winter months.”
Scientists will retrieve the trackers to obtain the location data when the birds return to the colony next breeding season.
“The devices were specially designed to have no impact on the birds, and are only the size of a five cent coin, weighing just 1.5 grams,” he said.The project is part of a wider long term collaborative study of Antarctic predators, including Adélie and Emperor penguins, using a variety of methods including tracking, population surveys and automated cameras to monitor breeding colonies in East Antarctica.
“This summer the cameras will be deployed at new locations along the coast, allowing us to monitor breeding populations without needing to visit the sites each year,” Dr Southwell said.
“We are already gathering valuable information from cameras stationed at breeding colonies on three islands near Mawson station and two islands near Davis station.”
This research will provide valuable information on long-term change in the Southern Ocean ecosystem and will feed into the Integrated Marine Observing System.
The Mawson and Davis station researchers will sail on the Aurora Australis on the first voyage of the season today and the Casey station team will fly south in early February.