Through a combination of lab
and field based work, my project aims to investigate the influence
of geography and environment on
the energetics and behaviour of the little penguin (Eudyptula
minor). In recent
years the little penguin has shown vulnerability to human-induced
environmental change; showing decreases in both breeding success and
population size at Phillip Island (VIC). In contrast, other
geographically distinct populations such as the Furneaux Islands
(TAS) are thriving and even expanding. While these differences may
be due to local differences in resource availability, they may also
suggest a capacity for flexibility in physiology and behaviour and
perhaps indicate innate levels of resilience and tolerance to
change. Indeed if you examine the
literature, population differences are evident in regards to several
physiological traits including resting metabolic rate, oxygen stores
and thermoregulatory costs. Such differences could easily have
important implications on the foraging strategies utilised by the
penguins, as well as their reproductive success.
Lab based work
While little penguins
spend a large time at sea foraging they are not exclusively marine
and spend considerable time on land when breeding or moulting. Lab
based work will therefore focus on the different thermal and
energetics costs associated with these environments. To further
explore the existence of geographic variation in little penguin
physiology I hope to carry out these experiments on several
populations. By utilising the same equipment and protocol I will be
able to determine whether the previously reported variation was
simply due to methodological differences.
Field based work
Earlier work by the AERP lab has shown
that heart rate is a reliable indicator of energy expenditure in the
little penguin. Long-term data on energy expenditure is useful as it
allows identification of periods in the penguin’s annuals lifecycle
where they exert the most pressure on their environment (i.e.
highest rates of food consumption) and are thus most vulnerable to
environmental change.
Jon Green (Research Fellow) is currently
utilising this technique to investigate behaviour and energetics in
little penguins at Phillip Island.
I hope to expand on Jon’s
project by continuing to collect data at Phillip Island next season,
as well as at two new sites Troubridge Island (SA) in collaboration
with
Simon Goldsworthy
(SARDI) and the Furneaux Islands (TAS) in
collaboration with
Cath Meathrel
(La Trobe University, Albury-Wodonga). By comparing these three
geographically distinct populations we hope to gain further insight
into how the little penguin adapts to the varying biotic and abiotic
challenges it faces across its range. Additionally, by undertaking a
second year at Phillip Island we can observe how the penguins adapt
to inter-annual changes at a single location. We feel such data
would be beneficial not only in the development of ecosystem models
used by fisheries, but also to aid the conservation effort to ensure
the long-time viability of this species, with a particular focus on
geographically isolated populations.
