Foraging ecology of Emperor Penguins at the
Snow Hill colony, Antarctic Peninsula

©Graham Robertson

January 2011

Proponent: Graham Robertson, Australian Antarctic Division, Channel Highway, Kingston Tasmania 7050 Australia.


© Graham Robertson

The aim of the research program is to study the foraging ecology of emperor penguins at the Snow Hill colony in summer (December-March). Emphasis will be placed on seeking understanding of factors affecting survival of a) fledglings on their maiden excursion from the natal site and b) adults during the pre-molt and post-molt fattening phases of the annual cycle.

Of these two areas, knowledge of the pre-molt and post-molt fattening stages and their locations is especially important because both are critical to the emperor penguin annual calendar. Because emperor penguins typically lose more than 30% of their body weight during the molt, it is important they are able to fatten normally both before the molt and after the molt (to re-build body energy reserves) before the new breeding season. Once breeding commences male emperors must fast for four months (females fast for half this period) to successfully raise their chick. Any influences that impair the capacity of emperors to return to normal body weight before and after the molt has the potential to affect breeding frequency as well as the survival of adult and chick as the breeding season unfolds

Factors affecting survival are likely to be interactions with commercial fishing (krill, finfish) operations in the Weddell Sea and South Atlantic regions, and global warming related changes to the dynamics of the pack-ice zone and the food web. The results of the program will be published in the international scientific literature and submitted to appropriate management for a, such as the Committee for Environmental protection of the Antarctic Treaty and the Commission for the Conservation of Antarctic Marine Living Resources (oversees the management of ecologically sustainable fisheries in the Southern Ocean).

[slidepress gallery='marmabio-station']

Research questions

Question 1: What are the foraging ranges, extent of dependence on the pack-ice zone and extent of overlap with commercial fisheries of fledglings on their first trip to sea, and adults during the pre-molt and post-molt phases of the annual cycle?

Question 2: How do the foraging patterns of fledgling and adult emperor penguins vary between years?


Team leader Barbara Wienecki with a fledgling Snow Hill Emperor.

The project will be conducted jointly by the Instituto Antarctico, Argentina, the Universidad de la Plata, Argentina, and the Australian Antarctic Division.


Since this is a logistically complicated study that has never been attempted before, a step-wise approach is proposed as the best way forward. Thus, the first two years of the study will be devoted to understanding how emperor penguins from the Snow Hill colony use the pack-ice zone in summer. Ideally contrasting pack-ice years (ie. a heavy versus light) will fall within the initial stages of the study. The first two years of the study will determine the feasibility of completing the intended five-year program and to help shape the final three years of the overall program.

Years 1 and 2

Adult and fledgling emperors from Snow Hill will be tracked for several months in the first two years of the study to quantify foraging ranges and use of the sea ice zone. This information gathered will provide knowledge on these hitherto unknown aspects of emperor behavior and will aid in the design of the remaining years of the study, which will present unique logistical challenges


Years 3-5

As mentioned, the nature of the research activities in years 3-5 will be contingent upon findings in years 1-2. The information below is based on the assumption that continued logistical support by Argentina is available, and that the location and capture of adult emperor penguins in the pack-ice zone using a chartered yacht is considered to be feasible.

© Graham Robertson

Activities in years 3-5 involve a third (and last) year of satellite tracking fledglings, three additional years (making five years in total) tracking pre-molt adults, and three years spent tracking post-molt adults.

Data on pre-molt adults will be collected over each of the five years of the study. In addition to the initial assessment in years 1 and 2, research on the post-molt fattening phase requires knowledge of the location of molt grounds to enable birds to be located and instrumented (research on the pre-molt stage must always be coupled to tracking studies during the pre-molt period). Thus, the pre-molt phases will be studied over five years, whereas the post molt stage and the movements of the fledglings will each be studied over three years.

The total estimated cost of this project is $980,000 over five years. Visit our page on Crowdrise to find out how you can help us with this project.