There are several naturally grown things which are good for an island like birds dropping. Guano is filled with nitrogen, a fertilizer that enhances the growth of plants and birds are the robust supplier.
However, there are some bad things as well, such as invasive rats that tend to destroy everything coming into their way, like eggs and chicks of bird, which do not know how to deal with their mammalian predators. But, the result of this sort of invasion is far from the impacting the ecosystem only, and even to the regions which never comes in your thought, which has the surrounding coral reefs on the island incorporated.
Graham, which tracking the element, could experience that how rats have impacted the population of seabird, that eventually impacts the nitrogen stores of the island. The collected samples of the soil of various parts of the island show that the region where there is no invasion by the rats, the amount of nitrogen elements from bird’s dropping is 250% more than the area invaded by the rats.
The research team as well discovered a higher level of nitrogen components in fish and reef algae in the area which is rat-free. Graham says, “The rats are responsible for interrupting the system, and seabirds avoid visiting that part of the island which impacts the nitrogen deposit.”
Director of science, Nick Holmes, Island Conservation group, says, “Rats were antedating the newborn saplings that were sprouting and consuming the seeds.” So, this makes the rats an unwanted group of engineers of the forest, and it is very much clear that forest is the baseline of every ecosystem, be it seabirds or invertebrates.
In 2013, as soon as the researchers started the eradication of the rats, the native seedlings increased by 130%, and the counting of arthropods such as crabs and insects went on high like a rocket with an increase of 350%.