Conservation work does too much killing – at least that is what compassionate conservationists’ say. The University of Technology Sydney describes this ideology as “an interdisciplinary field which promotes the treatment of all wildlife with respect, justice, and compassion.” Conventional wisdom from conservation and invasion biologists describes just the opposite: all invasive species are bad, need to be killed, and are “guilty until proven innocent.” However, many ecologists are calling for a more nuanced approach to this paradigm, especially in an age where climate change is forcing migration. Not only that, but in the era of globalization it is virtually impossible to eradicate all invasive species.
It is a known fact that the warming planet is changing animals’ habitats. A direct result of climate change is species having to move to survive. Countless examples of this have been cited: dark unicorn snails, white-tailed deer, maple trees. However, many ecologists view these species as “invasive alien species – the subset of alien species that spread widely in areas where they are not native, affecting the environment or human livelihoods” (Pyšek et. al, 2020). Although it is undeniable that many migrating species have negative impacts on their new homes, is it humans’ job to exterminate them for trying to stay alive? These animals are, in a way, practicing personal conservation. They are leaving old, inhabitable homes and occupying new habitats to conserve their species.
And who is to say what species are native, and which are not? Mark Davis, a biology professor at Macalester College in Minnesota says that judging a species based on its origins is highly controversial. In Banu Subramaniam’s book Ghost Stories for Darwin, she cites the symbiosis between a native and an invasive species: the monarch butterfly, native to California, and the eucalyptus tree, introduced from Australia about 125 years ago. While she acknowledges the trees have negatives, it is important to note that the endangered butterfly is now dependent on these trees during their annual migration; “In a world with profound human-induced movements of flora and fauna, a decision to suddenly decree what is native/ foreign seems rather arbitrary” (Subramaniam, pg. 138). It is also arbitrary to believe that just because something has not existed in a space since the beginning of time, it must be killed off. After all, how many years does a species need to exist in an area for it to be considered “native”?
Speaking to Subramaniam’s point, many humans pick and choose what they want to be native, and what they consider invasive; many states list the honeybee as their state insect when, in fact (according to the United States Geological Survey) honeybees are not native to North America. They were imported from Europe in the 17th century. But because of their incredible pollination skills, helping much of the flora and fauna in the United States, there is a growing conservation movement surrounding this species. Invasion biologists claim that we should not introduce honeybees in areas where you want to foster the growth of native bees, but it seems that many Americans have chosen to ignore that fact.
Additionally, an important paradox to consider is: what about species that are endangered and invasive? In 2015, a paper was published in the journal Conservation Biology, written by Michael P. Marchetti and Tag Engstrom, two California biologists. Their paper discusses the difficult question of what to do about animals that are invasive in some parts of the world but endangered in others. They provide the example of the wattle-necked soft-shelled turtle, native to Vietnam and China (and endangered there), but invasive to Hawaii (and detrimental to the precious freshwater ecosystem on the island). Dr. Olden is quoted in a New York Times article saying that “If we identify a plant or animal that might not be able to respond to climate change, do we roll the dice and intentionally move that species northward, or up in elevation?”
But all of this begs another, more philosophical question: do humans’ study and practice conservation biology to save the world, to “play God”, or to make themselves feel better? After all, in this age of climate change and what some scientists have labeled the “6th mass extinction event”, humans have now created species that only exist in captivity. They are virtually extinct in the natural world. If these animals are no longer filling an ecological niche, or playing a part in an ecosystem, why must we keep them alive? We can ask the same question about non-native species – why not let nature play its course?
