Comment by lemming
15 hours ago
This sort of thing is a huge problem here in New Zealand. The only native mammal here is a bat, we have mostly birds which evolved for a really long time with only avian predators. So they’re hilariously poorly adapted for surviving standard predators (cats, rats, dogs etc) which first the Maori and subsequently Europeans brought. For example, many of them are flightless and tend to freeze when threatened - works well against eagles but is a terrible idea when threatened by a cat.
As a result, we have many animals, mostly birds, which are totally unique and also critically endangered. Many of them can only survive on offshore islands which have been comprehensively cleared of predators at vast effort and expense. The islands need to be relatively accessible since humans have to get to them to maintain them, but it turns out that once in a while a predator will swim quite vast distances for no apparent reason, and it only takes one to mess up years of painstaking work. Quite apart from killing a bunch of birds whose total remaining numbers might range from the tens to the hundreds of individuals.
I too am flightless and freeze while threatened
My upvote didn’t feel enough for this comment. So here’s my kudos for a nice chuckle!
You are very kind! Thank you .
I love the visual of humans desperately trying to preserve what they consider the natural world, and when they turn their backs evolution does it's thing.
Nit: If predators periodically make their way to the islands without human assistance, don't the islands have native predators, by virtue of how we've woven ourselves into the definitions?
Alcatraz isn't really that far from land, about a mile away. They have events where you can swim to and from it. The currents make it dangerous, but the distance is unremarkable.
There are local clubs which swim from the island on a regular basis, year 'round. If not absolutely daily, several times a week.
Water temps vary by time of year, but are particularly mild from late summer through late fall. Even winter-time temps aren't particularly challenging. A dog could easily make the swim.
Currents are a challenge, but mostly if you're planning on landing at a specific point along the shore. If your goal is simply to make it to shore, they're far less an issue. Just swim cross-channel and you'll make it.
The physiological and psychological challenges are greatly overblown.
Most people cannot swim a mile.
Humans also aren't good swimmers, and we assume all land mammals are as bad as us.
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Is it really only a mile? There are coyotes on islands in Washington that would’ve swam further than that through some strong tidal currents.
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All the same every year > 2,000 people attempt the 12 mile swim to see a cute Quokka on Rottnest Island.
* https://rottnestchannelswim.com.au/
* https://en.wikipedia.org/wiki/Rottnest_Channel_Swim
Mind you, that's largely Australians who grow up swimming more than many US Navy SEALs do.
Come on down, the waters fine, the sharks rarely nip.
I'm suprised to see a HN comment along the lines of "most people don't ...", after all, most people don't program computers, start million and billion dollar companies, build out datacentres, fly planes, ... etc. The site is littered with people confidently doing things most people do not.
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Direct ecological management is unfortunately a bit of a game of using a bucket to fix a leaky ship. The equilibrium that established the ecosystem dynamics in the first place is disrupted. A new equilibrium might form over time, but we enforce the old one because that is what we documented when we first came to a place, even though it is no longer thermodynamically favorable.
Ironically, the ecology of an island itself came from events like a random animal swimming to it over the historical record and finding sufficient spare resources or an ecological niche they could satisfy sufficiently to reproduce. Distance from mainland and species diversity is very strongly correlated reflecting increasingly scarce odds of these "heroic journeys" at greater distances. Species themselves are capable of exhausting an islands resources and putting themselves into local extinction even with no human intervention (such as the case of the last of the mammoths on wrangel island).
A lot of work and money has gone in to preventing zebra mussels from spreading to new lakes in Minnesota. Think free sites for people to have their boats cleaned when they’re going from lake to lake, PR campaigns, etc.
My parent’s small pond, which has never seen a boat or any other real human activity, got them before the big lake it’s connected to did. Clearly there was some other way they could spread, presumably by bird.
Anyways, one by one every lake in the area no has zebra mussels. Even if they would only spread via human, it was clearly only a matter of time. As much as they suck (they’re sharp and attach themselves to basically anything in the lake) I’m not sure the expense has been worth simply delaying the inevitable.
Probably a swallow. They could carry them.
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> I’m not sure the expense has been worth simply delaying the inevitable.
Now that I'm jaded I ask myself how many government and private sector jobs were "created" (in sarcasm quotes because broken windows fallacy) washing all those boats for free over the years and whether they even expected to prevent the spread or if the spread is the justification for expansion.
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It's really odd stuff, humans are obsessed with declaring one moment in time as the "right one" and then trying to keep it like that forever. Evolution? We need to document gods work! People driving their SUV to protests for "conservation", the irony is thick.
We can acknowledge historical change while still acting to prevent unnecessary modern destruction. To my set of values, these ecosystems are worth protection from the accelerated decay almost always caused by human development, and losing them to indifference is a permanent tragedy.