Hi just another question, How do you confine an area with invasive species not native to an island country? Especially if my forementioned invasive species can fly and destroy the native bird population.
with a 12 gauge or a really really big net... You may have to modify the story a little to do it believably. Depending on your setting you could use a force field or invent some other technology. A better way may be to write in limits in the endurance of your invasive pests, such that they don't have the stamina to make it across the water to the mainland. That way your characters could worry about it (cuz there's always a chance...) but not have to do anything about it.
Make it so that the land / island around said confined area is uninhabitable by the invasive species. Perhaps this species can only nest in a certain type of tree which only is able to grow in this one area because the soil elsewhere isn’t sufficient, etc.
Honestly, you probably can't. Assuming they don't have the endurance to fly off the island you still have to cut it off from all human contact, which is probably out of the question since you mentioned it's a nation. You never know when one or more of your creatures are going to jump ship, or fishing boat, or airplane, or stiff tail-wind, or even drifting log. How do you think tortoises got to the Galapagos? And they're far from invasive. Of course, it's a little easier if they're big because then you can go a-hunting, but most invasive species aren't. They're almost always small, breed fast, do not have specialized mating or habitat requirements, and eat anything. Large varieties need to have the ability to either hide extremely well or take on armed groups of humans.
The government might try to bring in a predator species to wipe out the invasive species you're talking about. That solution could be a success or more likely an ironic failure...
Introduce a natural predator that predates on that species. Other then that you could poison the adults right before the offspring hatches. Then they wont be able to properly take care of their offspring, and you kill both generations at once. If you need a faster solution hunting would be an option with ofcourse a incentive for the hunters like 25$ per carcass.
It's not likely. That's why invasive species are such a big problem. The only way would be to systematically destroy the invasive species population down to a small enough level that the native species are able to compete with it. You can bring in another invasive species (but that doesn't usually bring about the intended results) or you can start some sort of program such as a hunting and egg-destroying project.
Also, predator-prey populations tend to stabilize. Bringing in a predator wouldn't eradicate them, only, at best, keep the population under control and stable.
you cant. look at the japanese beetle. or kudzu. theyre everywhere. and introducing predators doesnt always work. sometimes they just eat everything but what you want them too. If its something big like a wolf you could theoretically chase them all towards a trap. but if its say an insect youd probably be best off finding a disease that would only affect that specific organism. or take the andromeda strain route, find an organism/chemical/disease that wont hurt the natives but is deadly to the invaders
everyone else has covered it pretty well, the best method is prevention, but some animals are very adaptive (cockroaches in US came from Europe, snuck over on ships) and are quick to find themselves a niche. Some animals are bettered suited for a variety of environments. Once the pest spreads, you can try to introduce a predator, if it even has one, and hope that that works. You can hunt them down too, if they arent a protected species, but if they breed rapidly they will be hella hard to track down The Coqui frog in either Guam or Somoa, cant remember Species of Monkey in the West Indies Roaches and rats in the Americas Interestingly the poor Koala bears and Panda bears are both going extinct, and its not just our fault. When you have an animal that has a diet that consists almost exclusively one kind of species of plant (the former Eucalyptus and the latter Bamboo), combined with the fact that they dont breed, yaaa-theyre gonna die out. I dont care how cute they are, nature does not discriminate. Some animals are just better suited for success for a particlar epoch of time. All life on this planet now would die instantly if exposed to Earths atmosphere a few billion years ago, before we had an abundance of Oxygen. Nature is funny like that...
Beyond what has been indicated: Possibly sterilize all specimines of the invasive species before they're is released into the island habitat.
What, you think the absence of frog DNA is going to stop them from adapting? In the famous words of Ian Malcom "The plot will find a way."
You cant find and sterilize all of them, if you could do that, you might as well catch and kill every one of them too. I think the scenario is an involuntary introduction to the environment, so no preventive measures taken before, right? I might have got the OP wrong though
No can do. I think the inability to control the creature/plant is the defining characteristic of an invasive species. Sooooooooooo may examples, world wide. Many have already been mentioned here. Our efforts to control them are at best, poor, at worst, stupid. By stupid, I mean the idea that bringing in another species to control the first species is going to be a good answer. Again, sooooooooo many examples of how completely wrong that idea is. An invasive species with which not too many are familiar unless you live in the affected areas is Caulerpa taxifolia. It is pretty much sterilizing the Mediterranean Sea and giving California (and I believe also Australia) cause for concern.