Foraging ecology of Gentoo penguins

Project overview

The charismatic gentoo penguin is an iconic species inhabiting islands of the Southern Ocean and Antarctica. The Falkland Islands are home to proably the world’s largest population of these birds, with an estimated 130 000+ breeding pairs (34% of the global population). Because of this, determining the factors that may be affecting their foraging ecology in this region may assist in conservation measures on a global scale for these birds. Furthermore, the gentoos may be particularly unique in that they are considered sedentary and seldom leave the vicinity of their natal archipelago.This makes them a great indicator species for the state of the local marine environment.

Fundamentally, my project asks where and why do birds go where they do, and for what?To answer these questions, I have been utilising a suite of animal-borne technologies which include GPS devices, time-depth recorders, accelerometers and video cameras, as well as the laboratory methods of stomach content and stable isotope analysis.

My initial findings have shown that these birds tend to be considered generalists on a broader scale but at the level of the colony some specialisation occurs, likely driven by food availability and the surrounding habitat. Birds feeding in surrounding waters, which are generally shallower with gradual sloping seabeds, tend to have a broader trophic niche.

This is in contrast to those inhabiting colonies surrounded by deep water and a steeply sloping seabed.

Delving into the world of these birds through video cameras has proved a fascinating journey. We have seen, for the first time, these birds engaging in underwater intra- specific kleptoparasitism (food-theft within a species) and also come to realise that a common prey item, lobster krill (Munida gregaria), might be too intimidating to prey upon when in tight packed swarms.This latter discovery gained much attention at the 9th international penguin congress, where, I received the award for best presentation.

Publications:

Handley JM, Connan M, Baylis AMM, Brickle P, Pistorius P (2017). Jack of all prey, master of some: Influence of habitat on the feeding ecology of a diving marine predator. Marine Biology (In press) Carpenter-Kling T, Handley JM, Green DB, Reisinger RR, Makhado AB, Crawford RJ, Pistorius PA (2017). A novel foraging strategy in gentoo penguins breeding at sub-Antarctic Marion Island. Marine Biology 164: 33. Clucas GV,Younger JL, Kao D, Handley JM, Miller G, Jouventin P, Nolan P, Gharbi K, Miller K and Hart T (2016). Dispersal in the sub-Antarctic: King penguins show remarkably little population genetic differentiation across their range. BMC Evolutionary Biology 16: 211

Conferences
5-9 September 2016: International Penguin Congress
• Award: Best student presentation

14 June 2016: South African Network for Coastal and Oceanic Research (SANCOR): Student Conference
22-24 March 2016: Student Conference on Conservation Science: Cambridge, UK
• Award: Runner-up, best student presentation
10-11 March 2016: FLOCK in Kruger: BirdLife South Africa Conference

Skills development
18-21 March 2016: Introduction to Q GIS mapping software course 11-12 October 2016: Introduction to agent-based modelling workshop
12-16 December 2016: Introduction to statistical and machine learning course