I was surprised readinng the comments that so many people feel as I do: human beings are the problem, not feral cats. This article just gives people permission to be even more cruel to animals than we already are. I am not a Christian or anything else for that matter, but I am very familiar with the Bible and we should be stewards of this earth, not the primary destroyers. We have the judegement and ability to conrol our population, but the Smithsonian and other institutions that should be shouting out loud that there are too many people and we should do what we can to curb our numbers are doing nothing to get this message across. And they have all those researchers who make one mess after another trying to control nature in one way or another. First annhilate wolves, then reintroduce them, then start shooting them again. What happened to our intelligence and humanity? People need to spay or neuter their cats and dogs. It is that simple. If we did that, there wouldn't be feral cats and dogs who suffer pretty terrible lives. But I think that given the choice, they would choose to live, just as we would.

Man has been the cause of every problem in nature. For that matter in everything on Gods Green earth. Ive been sayin it for 30 years "There are just to many people"and yet world wide we continue to multiply into greater and greater numbers every day.

Photo#10 is a mongoose.Ohahu is covered with them.Introduced to rid the island of snakes.As far as invasive goes there are a lot of animals that aren't on the list,including humans.It depends on where you live,and how you define invasive.I'm over sixty,and I've seen a lot.I believe the earth will heal.The thing I like the best about all of the other animals,they don't have opinions.They don't pass judgements on each other,and they live within their environment.They don't try to change to suit their fancy.Wether you're a creationist or evolutionist man belongs here.I don't believe we came from outerspace.I'm a Christian and I believe we are part of God's plan.All of those"invasive" are too.I don't believe God sees them as invasive.

I am surprised that the virgina possusm,raccoon and the rock dove also known as pigeons. These animals had spread since the settlers had come from europe. As well the coyote from the west to the eastern part of United States.
I known about the feral cats killing wild bird populations as well,the domestic young duck,goose and turkeys. When I was a younger man. I had to help thin out the feral cat population on my cousin's and neighboring farms with my 22 long rifle.

I'm really not sure about your findings. Here in northern Wisconsin I've only seen where the more Red Squirrels you have the less Gray Squirrels you have.I've read where they actually do more damage than grays, by eating bird eggs, nesting in buildings, and actually chasing down grays when they come into their area. If I'm wrong let me know.

NUMBER ONE: Human Beings. I was really surprised you guys didn't know about this.

JERRY ANDREWS - I APPLAUD YOU!!! WELL STATED!!!!

I totally agree- the first guilty party here is the human race---mostly Europeans , their greed, arrogance and selfishness. there is no God that will fix this, we have to take care of the world ourselves. zMaybe we acn stop some of this, but I doubt it. Way too many humans are not in TOUCH with the earth. We are of the earth.

You really should have included Homo sapiens in this list.

Coyotes are overabundent here in New Your State. They have greatly reduced the deer herds by eating the fawns. There is a hunting season for them, but it doesn't seem to do much good so I guess the reproduction of coyotes is true. I don't think coyotes should be more welcome in the state than wolves who always get a bad rap due to the old stories.

The article probably ought to specify that specifically European rabbits are invasive in the Americas, given that there are plenty of native species.

We humans supposedly have the greater adaptive ability overall. An expression of that adaptive trait would be in recognizing our environmental role and impact. At least some can acknowledge the part we've played in the invasive species introductions that caused such ecological concern. Hopefully we are adaptive enough to come up with proper solutions to the mistakes made and lay a course correction wherever possible; and more importantly, let's hope we can learn from past mistakes and not continue to repeat them.

Very nice assortment of animals here and some interesting comments. As a devoted Christian, it is our responsibility to be good stewards of the gift that God has given us. Though I think the Lord will be coming soon, we have to keep our house clean until that day. Whether you want to consider humans as invasive or not, we have needs of the resources that are here, but we should not destroy our homes (ie, the environment outside my door which includes the whole earth). It is sickening to watch areas that are livable being destroyed by greed. In the last forty years or so, we have doubled from 3.5 billion people to 7 billion people. Everyone of them is or was someones darling baby (or grand baby). Let's manage the world so that all of God's children (those alive today and those coming in the future) can enjoy a wonderful world.

You left out humans.