Image credit: Jasper Koster / Phys.org

But is there a twist to this tale? From the research article we learn this:
‘The geese spend the winter and spring on the Solway Firth, United Kingdom. They utilize areas in Norway for spring staging, and breed on the high‐arctic archipelago of Svalbard (Figure 1; Owen & Black, 1999). Recently, a small but increasing number of barnacle geese spend the pre‐migratory period on the Solway before heading directly towards Svalbard (LG, unpublished), which was disregarded in the current study due to a lack of quantitative data.’

Why are they now – apparently at least – staying longer on the Solway (south coast of Scotland) in the spring and bypassing their ‘spring stage’ in Norway? As Dutch researchers asked two years ago: Can barnacle geese predict the climate?
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Migratory animals are actively adjusting their traditions to climate change, new research has found.

An international team of researchers from the University of St. Andrews, with Norwegian, Dutch and British colleagues, found that barnacle geese have shifted their migratory route within the last 25 years, reports Phys.org.

In research published in the journal Global Change Biology, the research team concluded that individual geese have decided to change to the new route, and that other geese now learn the new habit from each other.

The study is among the first to provide hard evidence that wild animals are inventing new traditions to cope with climate change.

The migratory birds, who traditionally fueled up (staged) just South of the Arctic circle in Norway on their journey from the UK to their breeding grounds on Svalbard, now mainly stage in northern Norway far above the Arctic circle.

The conclusions are based on analysis of 45 years of observations by the Norwegian Institute for Nature Research, the University of St Andrews, the University of Groningen in the Netherlands, BirdLife Norway and the British Waterfowl and Wetlands Trust.

Dr. Thomas Oudman of the School of Biology at the University of St Andrews said: “It makes sense that the birds went even further North, because where snow used to be very common there at the time of their arrival in Norway, these days it is often freshly green there: the most nutritious stage.

“What surprised us is that it is mainly the young geese who have shifted. The youngsters are responding to a trend they could not have experienced during their short life.”

Adult geese are also increasingly shifting north, although they often return to the traditional area in their old age.

Dr. Oudman added: “These patterns point at a complex social system, which enables the geese to rapidly colonize newly available areas.”

Contrary to most other migratory birds, barnacle geese flourish even while their natural habitat is rapidly changing.

Full report here.
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Study: Northward range expansion in spring‐staging barnacle geese is a response to climate change and population growth, mediated by individual experience [open access]

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September 5, 2019 at 04:48AM