Pantanal Dispatch Day 4

The work that Alexine Keuroghlian is conducting in the Pantanal is directly linked to the ecological issue of invasive species. In this particular case, she is studying the effects of feral pigs and javonteiro (European boars bred with feral pigs) on indigenous populations of white-lipped and collared peccaries. Because the introduction of feral animals and exotic species to an ecosystem can cause significant harm to the ecological health of a region and to native species – not to mention the potential economic and cultural implications – it is important to understand the issue.

Human actions have historically been the culprit in introducing exotic species to new regions. Whether by accident or on purpose, the introduction of exotics almost always has implications on the ecosystem. When placed in a new habitat non-native species often have no natural predators and as a result, can spread or propagate easily and quickly. This poses a huge threat to the native species in the ecosystem; when exotics and natives exist near each other, they compete for food and space, and can also develop unbalanced prey/predator dynamics. If exotics invade a region too rapidly, indigenous species frequently cannot successfully compete for resources, and natives can be smothered or killed. This will cause food webs in an ecosystem to be restructured with effects that can be seen up to the top carnivores.

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Exotic species can also import new diseases into native populations. While invasive species may have developed resistance to these diseases, indigenous species will not necessarily have immunity against these foreign threats. Because it takes time for immune systems to build up a defense against new diseases, native species may be weakened or entirely wiped out before they get the chance to combat the disease.

A threat similar to exotic species is the problem of feral animals. Feral animals are either domesticated animals gone wild or animals introduced into a region for recreation, pest control, or another specific purpose. Just as with exotic species, feral animal populations can rapidly multiply, allowing them to out-compete native species. They can also bring in new diseases and parasites to native populations, or directly prey on native species.

Preventing the transference of exotic species and the release of feral animals before they happen is the best method to address these problems. However, this is easier said than done. And once a harmful non-native species has been introduced, it can be very difficult to eradicate. There have been some successes in controlling exotic and feral species by chemical, mechanical and biological methods. Researchers like Alexine are helping to find answers to the dilemmas posed by non-native species, and preparing strategies for restoring ecosystems to their natural states – complete with healthy native flora and fauna communities.

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