Do Italian chamois prove global warming?

In the Italian Alps there are records of the weight of animals shot by hunters -- and the carcasses of chamois goats are now quite a bit lighter than they used to be.  Why?

The Warmist researchers below discovered that betwen 1979 and 2010 temperatures in the study area rose substantially  -- by around 3 degrees.  And that is the first oddity.  Global temperatures over that time rose by only tenths of a degree.  So there were some LOCAL effects at work on temperatures in the area.  The results tell us nothing about GLOBAL warming.

But do they tell us anything about what might be if the whole world warmed by the same amount?

Probably not.  In best Warmist style they used models to analyse  their data,  thus introducing possibilities of arbitrariness.  And the result is that there is no clear test of whether temperature was the driver of the effects observed.  And there was another clear driver -- population density.  The population of animals in the study area rose during the time of the study. So if there are more goats competing for feed each goat is likely to be less well-fed.  And calorie deficiency is well know to shrink body mass.

So competent research would have used some type of regression analysis to remove the effect of density before temperature effects were looked for.  The authors did not do that.  They simply plugged in both density and temperature into their models -- leaving unanswered whether there was any statistically significant effect of temperature after the variations in density had been allowed for.  Very sloppy!

Goats are shrinking as a result of climate change, researchers have claimed.  They say Alpine goats now weigh about 25 per cent less than animals of the same age in the 1980s.  Researchers say it is a stark indication of how quickly climate change can affect animals.

They appear to be shrinking in size as they react to changes in climate, according to new research from Durham University.

The researchers studied the impacts of changes in temperature on the body size of Alpine Chamois, a species of mountain goat, over the past 30 years.  To their surprise, they discovered that young Chamois now weigh about 25 per cent less than animals of the same age in the 1980s.

In recent years, decreases in body size have been identified in a variety of animal species, and have frequently been linked to the changing climate.  However, the researchers say the decline in size of Chamois observed in this study is striking in its speed and magnitude.

The research, funded by the Natural Environment Research Council is published in the journal Frontiers in Zoology.

Lead author Dr Tom Mason, in the School of Biological and Biomedical Sciences, at Durham University, said: 'Body size declines attributed to climate change are widespread in the animal kingdom, with many fish, bird and mammal species getting smaller.

'However the decreases we observe here are astonishing. 'The impacts on Chamois weight could pose real problems for the survival of these populations.'

The team delved into long-term records of Chamois body weights provided by hunters in the Italian Alps.

They discovered that the declines were strongly linked to the warming climate in the study region, which became 3-4oC warmer during the 30 years of the study.

The team believes that higher temperatures are affecting how chamois behave.

'We know that Chamois cope with hot periods by resting more and spending less time searching for food, and this may be restricting their size more than the quality of the vegetation they eat,' said Co-author Dr Stephen Willis.

'If climate change results in similar behavioural and body mass changes in domestic livestock, this could have impacts on agricultural productivity in coming decades.'


Environmental change and long-term body mass declines in an alpine mammal

By Tom HE Mason et al.


Climate and environmental change have driven widespread changes in body size, particularly declines, across a range of taxonomic groups in recent decades. Size declines could substantially impact on the functioning of ecosystems. To date, most studies suggest that temporal trends in size have resulted indirectly from climate change modifying resource availability and quality, affecting the ability of individuals to acquire resources and grow.

Here, we investigate striking long-term body mass declines in juvenile Alpine chamois (Rupicapra rupicapra), within three neighbouring populations in the Italian Alps. We find strong evidence that increasing population density and warming temperatures during spring and summer are linked to the mass declines. We find no evidence that the timing or productivity of resources have been altered during this period.

We conclude that it is unlikely that environmental change has driven body size change indirectly via effects on resource productivity or phenology [growth cycles]. Instead, we propose that environmental change has limited the ability of individuals to acquire resources. This could be due to increases in the intensity of competition and decreases in time spent foraging, owing to high temperatures. Our findings add weight to a growing body of evidence for long-term body size reductions and provide considerable insight into the potential drivers of such trends. Furthermore, we highlight the potential for appropriate management, for instance increases in harvest size, to counteract the impacts of climate change on body mass.

Frontiers in Zoology 2014, 11:69  doi:10.1186/s12983-014-0069-6

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