As with most introduced and invasive species, the Brown Tree Snake has had devastating impacts on Guam’s ecosystem. Since the introduction of the snake, there have been many losses to the local ecosystem, with the extirpation of many local and native bird and lizard species, and population decreases of the flying fox and other lizard species (Rodda & Savidge, 2007; Rodda, Fritts & Conry 1992; Wiles et al 2003; Rogers et al 2017; Wald et al. 2019). However, indirect losses, such as a decrease in forest trees due to the absence of essential seed dispersers have a lack of recognition (Rodda & Savidge 2007; Rogers, et al. 2017; Fritts & Rodda 1998).
The reason for the Brown Tree snake's exponential increase on the island was due to the fact the snake has no natural predators in Guam, which is why it was able to quickly extirpate local forest bird species, as well as native lizard species (Rodda & Savidge 2007; Rogers et al. 2017; Fritts & Rodda 1998; Mortensen, Dupont & Olesen 2008). In Fritts and Rodda’s The Role of Introduced Species in the Degradation of Island Ecosystems (1998), as well as Mortensen, Dupont and Olesen’s A Snake in Paradise (2008), six of the ten to twelve lizard species – they are not completely sure as to how many native species there were as the islands with similar animals and ecosystems have varied numbers and the disappearances of some species were poorly documented (Fritts & Rodda 1998) – are now extirpated on the island. However, in another article, Rodda, Fritts, and Conry (1992) predicted that the Brown Tree Snake would cause such extirpation on not only lizards but birds and bats as well, however, it was not a reality at the time.
Save your time!
We can take care of your essay
- Proper editing and formatting
- Free revision, title page, and bibliography
- Flexible prices and money-back guarantee
Fritts and Rodda (1998), again, were the first to report that ten of the twelve native bird species have been extirpated, but this has been reinforced by other journal articles, particularly by Wiles (2003), Savidge (2007), Pollock (2019), Rogers (2017) and Wald (2019). Pollock, Savidge, Kastner, Seibert, and Jones state that a reason for the extreme decline and extirpation of Guam’s native bird species is that the birds have no native predators on the island so they can be considered “ecologically naïve” (Pollock et al 2019) making them more susceptible to predation by the snake species. Wiles, Bart, Beck, and Aguon (2003), however, were the first to go in-depth into the decline of the avifauna, and avifauna was the most affected by the introduction of the Brown Tree Snake. They identified fifteen bird species, some native, some introduced, that had been greatly affected, and another four that had recently shown a decline with no recovery (Wiles, et al. 2003). They identified twelve species that had been completely extirpated on Guam, with only two of them being introduced species (Wiles, et al. 2003).
Wiles, Bart, Beck, and Aguon recommended the instillation of nesting boxes on the outskirts of the forest to encourage the native birds to live away from the predatory snakes while still being in the forest to gather food and implemented this on the island, hoping it would also encourage the birds to return to the island (2003). Pollock, Savidge, Kastner, Seibert, and Jones also recommend the instillation of nesting boxes, however, expanding on the idea, they recommend placing them in urban areas at a distance of at least one hundred and fifty meters away from the forest edge (2019). They decided to be a good distance away from the forest as the adults are still able to access the forest easily while also protecting their young, reducing their predation by twenty-five percent or more (Pollock et al. 2019). They found that the urban areas serve as a refuge for the birds from the Brown Tree snake predation, possibly due to the snake control measures in place in these areas and the snake’s aversion to humans (Pollock et al. 2019).
Stuck on your essay?
