Direct evidence of a changed ecosystem under a changing climate

At the risk of repetition, I stumbled on an article on BBC News, which I found interesting: Polar Bear threat to Solway geese.

It definitely serves as an example 0f adaptation to climate change.

In short, with the continuous loss of summer sea ice in the Arctic, polar bears are having to find new methods of food collection, which has led them to the nests of barnacle geese on the island of Svalbard. It’s been observed that the bears have consumed as much as a thousand eggs in a single sitting, which is leading to a reduction in yearly recruitment within the geese colony. On the bright side though, some geese nest on the cliffs which, until the appearance of the bears, was the more risky option for the fledglings, but now probably the species best option to avoid population collapse (will the species serve as an example in adaptive pressures to future generations as the peppered moth currently is?).

From an evolutionary point of view, it is interesting case study in natural variation and adaptation, so I’ll be keeping an eye out for studies on this. However, from the view of climate change, this serves as a warning for the changing already being carried out (and will continue to do so with increasing severity) to inter-species relationship and ultimately ecosystem function.


3 thoughts on “Direct evidence of a changed ecosystem under a changing climate

  1. Tim, I find this fascinating because the changes are behavioral. Since I am primarily oriented toward plants, I usually think of natural selection via genetics and also coevolution of different species. But here we have signs of rapid resilience. The question is how much stress can a system take before it breaks down entirely. For example, the birds die out leaving barnacles without a homeostatic regulatory system, population control.



    1. There is certainly a question of viable population numbers. The only example that I’ve read regarding geese populations is the Magpie geese. At this point, it might be inference assumptions from other species, regardless though – the bears are a major pressure on the geese species. It is an interesting situation, but one that will need human involvement in conservation efforts because, as you suggest – the loss of the geese is going to effect other species as well.


  2. This is just the latest in a long line of depressing stories about Scottish seabirds, especially those that feed their young on sandeels.

    Evidence suggests climate change, in particular warmer winters, has resulted in major changes in the plankton in the North Sea that have probably reduced the availability and nutritional quality of seabird prey such as sandeels. Data on breeding success of species most sensitive to food shortages such as Arctic skua, kittiwake and shag suggest that climate impacts are greatest in the northern North Sea and Scottish Continental Shelf.

    From this study (160k pdf), or you can check out the RSPB.

    It’s noticeable here, the only guillemots I’ve seen in the last three years have been dead or dying. It’s disturbing to find them on the beach, clearly distressed at your presence but lacking the energy to try to escape.

    There are also less shag (a kind of cormorant) around, and I haven’t seen any arctic tern for three or four years.
    Although the report says that herring gulls are doing badly for the UK as a whole, that isn’t the case here – both they and the local oystercatchers appear to be doing well here. If anything, the gulls are increasing in number. Maybe less competition – or maybe (in the case of the herring gull) they are migrating up here from less favourable conditions further south.

    Our seals and dolphins are also in decline, although we don’t really know why.

    We’ve also had recent sightings of a basking shark locally, and a killer whale in the Firth of Forth. Basking sharks are common around Devon & Cornwall, they’ve never been seen this far north before.


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