Bob Ewing --“Butterflies have migrated across Eastern Canada this spring in unprecedented numbers, reflecting the warm winter throughout North America and raising alarm bells about what it might mean for other species.”The comments section of the CBC story, about the increase in butterflies in Eastern Canada, for the most part, shows that readers missed the real opportunity this story offers. The commentors prefer to toss around the climate change football with the supporters saying this shows climate change is real, and others denying that it is.
Change is natural and, in fact, is the only thing we can count on. The increase in the number of butterflies demands attention but discussion is better focused on what this means from an ecosystem perspective.
What changes does an increase in a species mean for the ecosystem within which that change occurs? The simplest way to understand this is to look at the food chain.
The food chain provides information about whom or what eats who or what, in other words, who is predator and who is prey. This may sound simple, except for the fact that all living things play both roles, predator and prey. Modern humans, when it comes to food, do their hunting, for the most part in grocery stores and farmers markets, and all they need to feed themselves is money or access to money or credit.
Back to the butterflies, they are eaten by and eat other beings within the ecosystem. When the number of butterflies increases the food the butterflies consume is in greater demand and supply will eventually be impacted. More butterflies mean more snacks for birds and other beings which dine on the winged wonders.
This will, for a time increase the supply of the birds etc. This means that those that feed on birds have a bigger buffet to pick from and so on and so on until something happens and balance is restored. What we do not know is what changes actually take place within the ecosystem when the balance is upset.
The missed opportunity I referred to in the opening of this piece is a learning one. Events, such as an increased migration of butterflies, or the death of bats, provide us with both a formal and informal means to develop classroom and other discussions around how ecosystems function.
When we study food chains and the interconnected relationships between the various members of the chain we are able to gain an understanding of how Nature works.
Everything eats and this is the common ground that connects us all together. Everything plays a role and we do not really know what role any one element plays until after it vanishes, and things begin to change. Balance is likely to be restored, and life continue but we do not know what that life will be like.
What we do know is that a creature had someone for lunch and was someone else’s lunch.
Questions remain: Who will go uneaten and who will go unfed if that creature is removed from the ecosystem?
What effects will these changes bring? These are questions that need to be answered before we shrug off a species’ disappearance, and roll on as though nothing of import took place.
