Impact of climate changes on an Antarctic seabird: linking foraging behaviors to demography.

Stéphanie Jenouvrier, Biology
Julie Kellner, Biology


Project summary

There is now ample evidence of the ecological impacts of recent climate change in marine ecosystems. Seabirds are relatively large marine organisms relying entirely on the ocean environment to feed and are good bio-indicator species of the ecological consequences of climate change on marine ecosystems.

In polar ecosystems, the sea ice environment is a critical habitat for many seabirds because it
influences the entire food web and provides a platform for resting, molting, feeding and breeding.  Therefore, the life history of Antarctic seabirds is tied to sea ice, and several studies have shown strong population responses to change in the sea ice environment. Climate model simulations developed in the fourth assessment report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) project that Antarctic sea ice will shrink dramatically by the end of the century. Such changes will almost certainly affect sea-ice dependent species.

While previous work has provided insight into the role of climate change for some seabirds, considerable uncertainty remains due to limited understanding of some of the climate-species linkages. The aim of this proposal is to include a more detailed representation of the processes by which sea ice affects the demography of an Antarctic seabird, the southern fulmar (Fulmarus glacialoides1). We are particularly interested in the processes by which seabirds acquire resources (i.e. foraging behavior and efficiency) and allocate their energetic resources (i.e. food load) between breeding, survivorship and growth. We will link these processes with a dynamic population model which incorporates contrasting sea ice conditions for different years.

Our project includes 5 objectives. First, we will describe foraging behavior in relation to sea ice
using satellite ARGOS trajectories of the southern fulmar. Second, we will estimate the impact of sea ice on the numerous demographic parameters using an extensive long-term data on the demography of the fulmar (48 years) and up-to-date statistical capture-recapture models. In addition, our third objective is to quantify the effect of foraging and weight changes on the demographic rates. Then, we will include these relationships between sea ice- foraging behaviors - weight change of adults and chicks into a demographic model to understand how sea ice affects population growth through its impact on foraging and weight changes. Finally, we will project the population responses of the southern fulmar to future change in sea ice by linking our demographic model to sea ice output from General Circulation Climate and Ocean Models developed in the AR4 of the IPCC.

The two first objectives expand current studies of foraging behaviors and demography involving
undergraduate and graduate students currently supervised by PI Jenouvrier. The three latter goals involve the development of novel approaches to understand and forecast the effects of climate change on species by including the acquisition and allocation of resources in demographic models. These approaches can be applied to other seabirds and marine organisms sensitive to sea ice changes, and will help guide conservation and management programs.