Photo credit: from the USFWS site - a honeybee
“Invasive Species” is a term used by naturalists and conservationists to describe introduced species that have an undesirable affect on native wildlife or flora.
Without question, some non-native species can be very damaging, but something that is overlooked far too often is the benefit to natural areas that is derived from the presence of non-natives. National Geographic published an interesting opinion piece on July 24, 2014 on this very topic. “It's Time to Stop Thinking That All Non-Native Species Are Evil” challenges us to examine the common knee-jerk reaction of wanting to eliminate introduced plants and animals, because many species are having a beneficial effect on their new homes.
The simplest example of this is found in something all of us do every day. Many of the plants we farm for our dinner tables did not originate in North America, and in addition to being our main source of food, these crops also provide food and shelter to countless numbers of native wildlife. It’s hard to imagine an argument against the benefits derived by these non-native plant species.
On the more exotic front, we can look to California to see how the establishment of non-native species can be a positive.
When naturalists there ripped out and poisoned spartina grass, they found that their efforts were harming the endangered California clapper rail. Efforts to eradicate the grass have been discontinued as a result and spartina grass will stay put.
Thankfully, a new school of thought among ecologists is blooming that is considering the value of leaving non-native species alone. The best example of the benefits of non-native species is that of the honey bee. As we know, honeybees pollinate fruit and vegetable crops and carry out the same service for many species of wild plants. They are one of the most important species in North America yet they are not native to the New World, having been brought here several times in the 1600s.
Though we’ve been taught to think “Native, good; non-native, bad,” native species are not always beneficial species. The insect that is killing more trees than any other in North America is the mountain pine beetle Dendroctonus ponderosae – a species native to North America. Non-native beetles are not having such a devastating effect.
“We predict the proportion of non-native species that are viewed as benign or even desirable will slowly increase over time,” wrote ecologist Martin Schlaepfer of the State University of New York in a paper published Feb. 22 in Conservation Biology. Because only a fraction of non-native species will cause biological and economic damage, researchers predict the opinion of non-native species will slowly become more positive as their contributions become recognized.
Photo credit: from the USFWS site - a California clapper rail
Scott Carroll of the University of California, Davis calls for a new kind of science he termed “conciliation biology.” Simply trying to eradicate all exotic species can be costly, he argues, and can harm native species. Introduced cats were eradicated from Maquarie Island off the coast of Australia after having driven two of the island’s bird species extinct, but with the cats gone an introduced population of rabbits exploded, devouring the native plants.
Surely, challenging our beliefs about non-native species can lead to a greater understanding of the role they play. It should be kept in mind that non-native wildlife are individuals who enjoy their lives as we do, and killing them has ethical as well as scientific implications.
Another significant point to remember is that the species that has had the most devastating effect on the environment is Homo Sapiens. Human activity devastates wildlife species and their native environment and it is the activity of this single species that has harmed biodiversity more than all others combined.
Before vilifying non-native species and cursing them with the tag “invasive,” we should look closely at who they are and what they do, and perhaps come to appreciate both.
Joe Miele is a writer for the C.A.S.H. Courier. He works for a spay/neuter group and is a non-native resident of New Mexico