AS the long, hot summer draws to a close, wasps can be seen in abundance, making the most of the ripe fruit in our gardens and parks. This year, there has been considerable attention to the increasing number of Asian hornets in the Island attributable to the warming climate. The presence of Asian hornets in Jersey is likely to change the Island’s ecological equilibrium. But as with any other predator, a natural feedback loop will balance the comparative numbers of hunter and prey. Already bees are exhibiting defensive behaviour by enveloping the interloper and collectively raising their temperature to ‘cook’ the hornet.
Climate change is often a factor in a new species taking hold and once established it can be very difficult to remove it from its new ecosystem. In the UK aggressive Argentine ants have been found in major cities. These ants often eat electrical wiring and they will displace native species by competing for food. Harlequin ladybirds first arrived in the UK and Jersey in 2004 and have now spread across the whole of the British Isles. Their presence has led to a noticeable decline in the 46 native types of ladybird.
New Zealand also has an issue with non-native species and the government has launched an ambitious plan to eliminate the most damaging non-native predators by 2050. These include rats, stoats and possums, which prey on birds, lizards and snails. New Zealand birds such as the kakapo evolved without the threat of mammalian predators and lost the power of flight, rendering them more or less defenceless against introduced European mammals.
Closer to home, there is a real danger that the mosquito that carries dengue fever will move into central and southern Europe if global warming is not held in check. A rise of more than 2 degrees would allow the mosquito to thrive in Mediterranean countries. Dengue fever is a very serious disease with no effective vaccine. Similar concerns have been raised regarding West Nile Virus, which has spread outside of Africa since 1999. A bite from an infected insect can cause encephalitis and lead to fatalities.
With the evidence for anthropogenic climate change mounting, the ecological disturbances are becoming more commonplace posing longer-term environmental health problems. As individuals and as a society we must acknowledge these issues, accept responsibility and take action to limit our use of fossil fuels and live more sustainably.
