Comments on: Effects of invading island rats ripple across land and sea

By: Dave Briggs

Dave Briggs — Wed, 27 Feb 2008 20:13:59 +0000

Whaddya mean, we’re pests? My family has lived on this island for generations!
Posted by: Rat | February 25, 2008 10:58 PM
Don’t take it personally Rat! LOL! One man’s pest is another man’s cute furry little critter!
Dave Briggs :~)

By: Ed Yong

Ed Yong — Tue, 26 Feb 2008 22:11:32 +0000

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By: Noe

Noe — Tue, 26 Feb 2008 20:13:52 +0000

Autumn- in the context of small island ecology, we generally consider a native species to be one which arrived on its own, without human assistance. Obviously, in your Hawaii example, people have been living there for several hundred years and have brought a whole suite of non-native species with them (though there are still a few ecosystems there which have a high proportion of native species). Not all of these are invasive, though- for example, lychee trees are cultivated, but have not spread & propagated on their own. Think “invasive”=”weedy”. Rats are definitely an example of a species which has been very successful at spreading worldwide with human assistance.
If a new species were to get to an island on its own, I think the usual approach would be to leave it there, UNLESS the species in question was known to be disruptive in other ecosystems and the island was functioning as a refuge for species which were there previously (in which case land managers would try to prevent it from establishing itself). Unfortunately, nowadays so many island species are threatened that these isolated islands are the last refuge for many, and they are managed so as to preserve what’s left.
Salim- if you dropped a bunch of cats off on the island, they would likely kill some of the rats, but they would also eradicate the ground-nesting birds. A similar idea was tried in Hawaii with mongooses to kill rats, although there it turned out that rats were nocturnal and the mongooses were active in the daytime, so the mongooses turned to the birds as a food source instead. Oops! Cats are also extremely effective at eliminating bird populations because they kill for play- they don’t stop when they have enough to eat.

By: Salim Fadhley

Salim Fadhley — Tue, 26 Feb 2008 15:09:26 +0000

What might happen if somebody introduced a blight of kittens to chomp on the rats?
If the island is so over-run by rats how long does it normally take for some kind of opportunistic predator to take up residence? And what were the rats eating once they ran out of eggs & chics?

By: autumn

autumn — Tue, 26 Feb 2008 13:04:34 +0000

For an island biome, where does one objectively place the “native flora and fauna” in the time line of the place?
I can state very confidantly that Hawai’i's ecology is not native, but only if I allow that the “nativeness” of a location is somehow plausible, and that it is to be compared to some standard of “nativeness”.
Do we stop after a couple thousand years, or do we attempt to preserve every rafting species, as these are the most pure invaders.
Not trying to be dickish, merely asking when the divide between native and invasive apply to a once sterile rock.

By: Ed Yong

Ed Yong — Tue, 26 Feb 2008 12:06:02 +0000

The rat is disturbingly more eloquent than some of the commenters I've had in the past... Oh and for anyone interested in the effects of invading island rodents, have a look at this post from the classic site.

By: Rat

Rat — Tue, 26 Feb 2008 09:16:32 +0000

@Brigit: thank you for your kind comment. Actually I’m not here for pies … though if you have some handy … er, I’m here to find long-lost family members. There’s a story handed down from my many-greats-grandma that some of my distant relatives were recruited by scientists to assist them in experiments… though that particular grandma was said to be a little confused before the fox… uh, never mind. I’d love to meet some long-lost cousins.

By: Brian English

Brian English — Tue, 26 Feb 2008 06:11:03 +0000

That was Macquarie Island of course…..

By: Brian English

Brian English — Tue, 26 Feb 2008 06:08:57 +0000

I understand the little rodents are causing lots of damage to wildlife on Maquarie Island in the southern ocean. Aided and abetted by their cousin rodents in the rabbit…..

By: Brigit

Brigit — Tue, 26 Feb 2008 05:17:35 +0000

But look at those pretty, beady eyes. That rat wouldn’t hurt a fly. I swear, she’s just here for some pies, then she’ll go on her merry way.