Images of climate innovation

Of giants and kings

This aerial photograph shows adult king penguin brooding chicks (the regularly spaced dots) and last year's chicks, which are identifiable by the irregularly spaced, bigger dots. Predictions suggest an increase in icebergs being released from Antarctica as a result of warming effects under future climate change scenarios. At British Antarctic Survey, our research investigates potential changes to foraging habits of higher predators (king penguins) if giant icebergs were to block foraging routes.

An aerial photograph of a King Penguin colony, with adults and chicks

In July 2017, an iceberg the size of the UK county of Somerset named A68 - broke off from the Antarctic peninsula. One of the concerns was its potential to ground near the island of South Georgia and block access for iconic species, such as king penguins, to offshore foraging areas.

In anticipation, a BAS science team equipped 18 king penguins with GPS and Depth tags. These recorded the location every half hour and depth every 5 seconds, allowing 3D tracks to be reconstructed. Data were downloaded by a radio link to a base station situated at the colony, so tags did not need to be recovered to obtain the data. In this case, we found that no large fragments of iceberg obstructed penguin foraging, but had it grounded, it would have obstructed access to feeding areas, with potential consequences for chick growth and survival.

In addition to trackers, aerial images of king penguin colonies were taken, allowing population counts and showing colony density, to examine the potential effects of the giant iceberg on population size and breeding success. As King penguins take two years to fledge, we observed two cohorts of chicks in a colony in February. The old ones survived the South Georgia winter with minimal parental care, being fed between five and zero times over a 5-month period.

Tracks and surveys are being compared to previous comparable data from non-berg years and with oceanography data to determine whether there is evidence for the berg causing changes (e.g. due to lowered temperature, salinity, or increases in iceberg fragments). This innovative combination of remote sensing technologies helps develop our understanding of how wildlife populations are affected by and adapt to climate change and contributes to informing management decisions to protect fragile and iconic ecosystems.

Entrant: Norm Ratcliffe , British Antarctic Survey

Copyright: British Antarctic Survey