Invasion of non-native species and ecosystem shifts
At a Kenyan conservancy, the invasive big-headed ant species disrupted a mutualism between native ants and acacia trees.
In which the native ants protected trees from grazers in exchange for a place to live.
When the invasive ants pushed out the native ants, the trees were left vulnerable to overgrazing by elephants.
Who browsed and broke trees at five to seven times the rate in areas with invasive ants.
Due to a more open landscape, lions were left without hiding places stalk their preferred prey of zebras.
Native species and ecosystem shifts – examples
Ecosystems are constantly changing, but the introduction of non-native species and human activities like climate change can accelerate these shifts.
Sometimes with negative consequences for native species.
1. Burmese Pythons in the Everglades:
Native species: American alligator, bobcat, deer, wading birds, fish
Introduced species: Burmese python
The pythons are voracious predators and have decimated populations of small mammals, reptiles, and birds.
This has disrupted the food chain and impacted the entire ecosystem.
2. Kudzu Vine in the Southeastern United States:
Native species: Oaks, hickories, maples, dogwoods, native grasses and wildflowers
Introduced species: Kudzu vine
Impact: The fast-growing kudzu vine smothers native vegetation, preventing sunlight and nutrients from reaching other plants.
This has led to the loss of biodiversity and habitat for native animals.
3. Cane Toads in Australia:
Native species: Quolls, marsupial frogs, snakes, lizards, small mammals
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