What labwork could I possibly be doing when working on penguins you may ask? Well let me explain...
As part of my project, I am interested in understanding how the diet of rockhoppers may have varied in relation to changes in their environment over the last decades.
Rockhoppers are opportunistic feeders, feeding mainly on crustaceans, fish and cephalopods. But how do we know what they eat? Whilst older studies often used stomach flushing methods to obtain stomach content, less invasive lab techniques such as Stable Isotope Analysis (SIA) are now more commonly used to infer birds’ diet.
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SIA helps us understand where animals feed and what they’ve been eating by analysing chemical markers that naturally accumulate in their tissues based on what they eat.
Isotopes are versions of the same chemical element that have different weights. For example, carbon (C) and nitrogen (N) each have a heavier and lighter form. These heavier forms, called stable isotopes, don’t break down over time, and they leave a chemical fingerprint that can be traced.
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Carbon isotopes (δ¹³C) tell us where penguins have been feeding, for example, inshore vs offshore waters.
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Nitrogen isotopes (δ¹⁵N) tell us what they’ve been eating, by showing how high up the food chain their prey sits (from plankton to squid or fish).
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So I am analysing carbon and nitrogen in feathers (to look at long-term trends) and blood (to understand more recent, short-term diet shifts). These insights will help us track how penguin diets and habitats are changing in response to climate change.
👩🏼🔬 Step 1 - Blood and feather extraction
👩🏼🔬 Step 2 - Blood and feathers preparation for SIA
👩🏼🔬 Step 3 - Continuous-flow isotope ratio mass spectrometry
Samples are then sent to a specialised lab for continuous-flow isotope ratio mass spectrometry using an elemental analyser and induction furnace interfaced to a mass spectrometer.
