If they swam there, no. Invasive species have to be introduced by humans, by definition! The effect of grizzlies on the island ecosystem is unknown, and that may be more of what you're talking about.
> If they swam there, no. Invasive species have to be introduced by humans, by definition!
So what do you call it if humans introduce a species to an island A that's really close to another island B — and then the species happens to make the short hop to island B on its own? In a causal sense, that species would not have made it to island B if not for us introducing it to island A.
The article says they probably swam across the Johnstone Straight, from the mainland. There's no mention whatsoever of introducing grizzlies to any nearby island.
If you're asking hypothetically, I'd guess it comes down to whether the islands were separate ecosystems, but Wikipedia would be a much better source than me.
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally.
> The term "invasive" is poorly defined and often very subjective.
I too read the Wikipedia article and this sentence prompted me to survey a few other places. Federal law in the US for instance.
Your quoted definition doesn't appear in the article covering _invasive_ species, only in "introduced species" which of course implies a human introduced them.
The first paragraph is Wikipedia's definition for invasive species as a kind of introduced species with additional attributes. It's the first sentence in the article.
US federal law might be different, I wouldn't know.
