Invasive Species: For the Better and For the Worst

    Invasive Species: For the Better and For the Worst

By: Kyanna Gonzalez

     Invasive species, for the most part, have a bad reputation in regard to environmentalists and biologists. Interestingly enough, some invasive species can benefit native populations who are endangered by providing an abundant source of food. In the article “Pigs to the Rescue: An Invasive Species Helped Save Australia’s Crocodiles” Anthony Ham writes how with over twenty-million residing in Australia, feral pigs are considered an invasive species and are estimated to contribute to the major loss of mammalian life as well as habitat loss. Arriving in the late eighteenth century with European settlers, the feral pig population expanded across Australia in the 1980s when the wild buffalo populations plummeted in part due to human efforts to contain the buffalo population growth (Ham 2022). With more available resources and land to grow, feral pigs grew to become an abundant source of food for a native apex predator that was coming close to extinction.  

    The saltwater crocodile has resided in Australia for millions of years and Mariana Campbell, a researcher at Charles Darwin University in Australia, describes these apex predators as being fairly lazy hunters who like to sit and wait for their prey to come to them. The invasion of the feral pigs allowed for dwindling crocodile populations to regain their size numbers. Dr. Campbell, who studies saltwater crocodiles in northern Australia, found that due to the high volume presence of feral pigs, the native crocodile population growth rates have increased due to a drastic change in their diet. Over the last 50 years, crocodiles have switched their diet to prey on more land animals than their ancestors who mainly consumed aquatic animals (Ham 2022). To obtain her conclusion that the feral pig's invasion directly impacted the crocodile’s growth in population, Dr. Campbell and her team of colleagues observed the amount of nitrogen and carbon found within the native crocodile's bones and compared them to bone samples of their ancestors. The bone analysis concluded that the feral pigs residing in Australia were now the crocodile's primary source of food. 

    Across the world, apex predators have benefited from invasive species. American alligators, across the gulf coast, were on the brink of extinction in the mid-twentieth century until a semi-aquatic rodent called the nutria invaded the coast. The presence of an abundance source of nutria allowed for the American alligator population to increase at drastic levels (Ham 2022). Another example of how invasive species could positively impact apex predator populations includes the wild pig and the Florida panther. With an estimated population of only 150 currently surviving in the wild, studies cited in Ham’s article imply that the wild pigs residing in Florida are the Florida panther's primary food source, and Mark Lotz, a panther biologist with the Florida Fish and Wildlife Conservation Commission, states “Hogs may have saved Florida panthers from extinction” (Ham 2022). With Florida having a subtropical climate and being the center for exotic ports, it has overall become a hotspot for invasive species. Ian Bartosek, a wildlife biologist with the Conservancy of Southwest Florida, draws attention to the fact that the state of Florida has “more established nonnative animal species than any country in the world” (Ham 2022). 

    As humans continue to import and export non-native species there is an environmental impact that needs to be addressed and made aware. Although some invasive species can benefit endangered populations, there is still a disruption within the local ecosystem that creates rippling consequences for all the life residing in that ecosystem. Purchasing local flora and fauna and refraining from exotic species can continue to promote and help maintain a healthy and balanced ecosystem in your community.

Reference Section

Ham, A. (2022, August 15). Pigs to the rescue: An invasive species helped save Australia's crocodiles. The New York Times. Retrieved September 11, 2022, from https://www.nytimes.com/2022/08/15/science/invasive-species-pigs-crocodiles.html