It would have meant running up the hill to the university to get there in time for the first lecture, and I'm not that fit, so I dawdled up instead and did a bit of admin while I waited for the coffee break.
Today's lectures were all themed on climate change, so it was good to link what I have been studying in Environmental Science with some of the issues faced by the penguins. Although there was some consideration of heat and increasing sea surface temperatures, more concerns were raised about the increase in frequency and intensity of extreme weather events like storms, winds and waves.
A consequence of rainstorms is that chicks' down gets wet and loses its insulating properties. Chicks less than three weeks old are particuarly vulnerable as they don't yet have waterproof feathers and can't thermo-regulate. Rebstock & Boersma found that 45mm of rain could lead to 100% chick mortality. Whilst such occurences are currently rare (once in every seven years or so), increased frequencies of extreme rainstorms will lead to increased chick mortality and decreases in colony size. Unfortunately, I'm not sure what practical action can be taken to mitigate this?Noella Tubbs from South Africa gave a presentation on thermo-regulation,which found that the temperature at which adult African Penguins suffer heat stress is much lower than previously thought at 28.6 oC. She did experiments using 'mock' penguins she had built to assess the temperature in various nest locations, and found differences of almost 10 oC in nests just metres apart, but in sun vs shade. Shade is obviously important in providing a more ambient temperature for the adults, and will mitigate them having to abandon their nests in order to cool down in the water. Concrete tunnels seemed to offer a good alternative where bushes are not growing, by providing shade and a through flow of air.
A third aspect covered by several presenters was that of wave action, which increases with the stronger winds that come from warming air due to climate change. There were a couple of points raised. First, heavy wave action makes the water more turbid and it carries lots of sediment, making it harder for penguins to see prey and feed. Other views considered the location and gradient of the thermocline. In settled conditions, this provides an invisible barrier above which phytoplankton thrive in the warmer waters, and fish will feed on them. This provides a distinct area that the penguins can hunt in, and many fish species will not move into the colder waters below so are easier to catch. In windy conditions, the water is mixed and the water column is a more constant temperature. This spreads out the prey, and makes it harder for the penguins to catch the fish. In all these instances, if the parents cannot catch fish efficiently, the chicks will suffer, and increased chick mortality means fewer penguins in the future.
On that not such a happy note, be reassured that penguins are watching over us from space :)
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