Moths are an important food source for the UK’s bats.
“Butterfly Conservation and the Bat Conservation Trust are asking people to take part in a “National Moth Night” on 15 May to find out more about the creatures and their habitats. They say UK moth numbers have fallen by a third in the past 40 years. This poses a threat to the bats that feed on them. There are now 17 species of bat in the UK, all of which are protected by law because their numbers have decreased so dramatically.”
“We need to learn as much as we can about which moths are facing the biggest problems so we can direct our work into protecting them and their habitats. That’s why we are appealing to the public to get involved and look for moths on their patch. Without moths, the whole of biodiversity starts to unravel.” – Richard Fox, surveys manager at Butterfly Conservation
When a species comes close to extinction, its link in the chain begins to loosen. Whilst measures have been taken towards moderately to highly endangered animals around the globe by creating wildlife sanctuaries, they have technically been removed from their natural ecosystem i.e. extinct in the wild. Certainly species have naturally (e.g. Ice Age) and unnaturally (celestial bodies colliding), come and gone over the centuries, but what occurs when a species continues to ‘annihilate’ numerous other species at an alarming rate? Once a chink in the chain separates, other species connected to that chain experience its effects. Regarding the article, moths, a primary food source for bats, are dwindling in numbers. If moths are dwindling in population, it’s corollary that bats will dwindle in population. Furthermore, consider the bats’ natural predators: raptors, owls, opossums and snakes. Frightening, to say the least.
So how does lighting fit into this equation? It’s very simple. Most organisms posses and operate under a circadian rhythm, i.e. 24 hour clock. The effects of Artificial light sources at on organisms’ circadian rhythms have been scientifically proven as detrimental. There’s an article here that attempts to hypothesize the relationship between the loss of moth populations and increase in light pollution. The article suggests two theories: moths confuse bright light sources for the natural moon light and once the moths are in the bright light, they’re literally blinded by the light and can not see how to escape it. Considering that, let’s move on to bats. To avoid its natural predators, bats fly in darkness to their hunting grounds. Regrettably, bats’ flight paths have become more dangerous, due to the lack of darkness. So what’s a practical solution to this problem? Shielded lighting. Shielded lighting directs the light where it is needed: downward. It can utilize lower wattage light bulbs to bright the same area a traditional unshielded high pressure sodium lights would. One can also employ motion sensors to emphasize light ‘when one needs it.’ When lights are pointed downward, organisms (humans included) can continue to function on their circadian rhythm. Sure, there are other factors that also affect species such as waste, water quality, pollution, etc. But consider the following fact: light pollution is 100% irreversible.
Let there be night!