Invasive Species Effect on Ecosystems

Taylor Schullo

Intro to Environmental & Sustainability

Principe & Parajuli

12 September 2022

Invasive Species Effect on Ecosystems

    The article "Pigs to the Rescue: An Invasive Species Helped Save Australia's Crocodiles" published by the New York Times, mainly focuses on two areas of the world: Florida and Australia.

    Feral Pigs were brought to Australia by English settlers in the late 18th century. The population has grown to 24 million today and across 40 percent of the land mass. While they tried to cull, or kill, the pigs and other invasive species, they were difficult to kill. Comparing them to saltwater crocodiles, they are Australia's largest apex predator which was close to extinction in the 1970s. In the northern territories, there were about 3,000.

    Without the feral pigs, "the population (crocodiles) wouldn't have recovered to the same level that they have," said Dr. Campbell, who studied their relationship (5). The population is back up to 100,000 in northern Australia because those crocodile's are eating the feral pigs. Populations of crocodiles have increased where pigs go near water, and areas with less pigs have seen a slower increase to the crocodile population. Using DNA analysis, scientists examined blood, skin, and bones to prove the crocodiles are indeed eating the pigs. They have been crocodile's main food source for the past 50 years.

    Another invasive species found in Florida, the wild pigs brought by Spanish settlers. Mark Lotz, a panther biologist, stated, "Hogs may have saved Florida panthers from extinction" (6). The panthers lost their main food supply of white-tailed deer due to culling. With about 150 adults left surviving in the wild, all remain in southern Florida around the hog population. 

    In the north of Lake Okeechobee in Florida, the island apple snails escaped an aquarium to now live in the wild. The snail kites birds started eating these snails and changed their breeding preference because of apple snails' large size. Studied for over 10 years, females wanted males with bigger beaks; snail kites have grown bigger because of apple snails.  

Not all invasive species have helped an apex predators or be good for the environment. The Florida hog has caused 1.5 billion dollars in damages to the areas every year. Australia has "lost 29 mammals since European colonization, and feral predators are implicated in 28 of these extinctions" (8).  Overall, combating invasive species is a hard process. By saving a species to control the population of another is a great example of how our ecosystems naturally work out. 

References: “Pigs to the Rescue: An Invasive Species Helped Save Australia’s Crocodiles.” New York Times, 16 Aug. 2022.