IN A WARMING CLIMATE IT'S RODENTS AND NOT JUST INSECTS THAT HAVE THE UPPER HAND

 



Climate change affects everything and everyone.  Most scientists are agreed that insects will thrive, together with weeds and parasitic species, but there's another critter that stands to benefit from a warmer climate: the rodent.

The four legged, usually furry, animal has a good chance of surviving global warming because the shift in climate provides it with more seed.   

But the little critters are not harmless.  In New Zealand, the battle has been on for centuries, as rats and stoats (see picture above) have wiped out wildlife, and plant life.  

The link between global warming and rodent life is alarming, some say.  Invasive mammals can wreak havoc in an ecosystem if their numbers suddenly spike. 

The reason for this, scientists believe is that global warming enhances seed production, and that includes nuts, acorns and other vital staples for rodents.  The process of seeding, called masting, has shortened its cycle.  Some plants like oaks only seeds every few years.  With global warming the cycle has been accelerated with more frequent seeding events in succeeding years. 

Beech trees in New Zealand, in another example, used to mast only six to seven years, but that pattern has been accelerated and is now in the 3-5 years incidence.  The new masting cycle has been observed in the past decade.

With additional rodents also comes a surge of rodent borne disease.  Rodents are notoriously infectious carriers, as was the case in the Middle Ages when the rats carried the plague on their backs of disease infected fleas. 

In areas of severe drought however, masting could be reduced, as a counter effect. 

In the continental US, the problem of more frequent masting has caused an explosion of feral pigs, which are very destructive and dangerous to humans.   Feral pigs too are carriers of sickness, such as pseudo rabies, which can decimate livestock. 

In the South west, deer mice population is incurring a similar fate, and with larger numbers of deer mice there is also the possibility of higher numbers of deadly hantavirus infections.  


Source : Scientific American/  7.8.13


No comments:

Post a Comment