Sooo, if they are/were popular as pets, how come there's less than 1000 left worldwide? Those two facts don't reconcile for me.
Sooo, if they are/were popular as pets, how come there's less than 1000 left worldwide? Those two facts don't reconcile for me.
1000 wild ones. There's much more in captivity than in the wild.
They evolved to be quite dependent on the unique agricultural islands in the Valley of Mexico called Chinampas. These were drained by the colonizers. Which is why Mexico City is now facing a severe water crisis and also why these creatures are endangered
Lake Texcoco was only partially drained by the Spanish. The big project to drain the lake was undertaken by President Porfirio Díaz in the early 1900s.
> Which is why Mexico City is now facing a severe water crisis
No it isn't. Mexico city has over extracted ground water for domestic and industrial use and is facing a drought, that's why they have a water crisis. It has nothing to do with the Spanish in the 17th century.
You're spouting a lot of a historical nonsense in this thread.
Thanks, that's the clarification I was not getting from TFA.
Also why the whole region has so many sinkhole and similar drainage problems - it's literally built on a lake.
Yup. A lake that used to fuel the single most productive agricultural system humans have ever practiced. It's sad but there is a strong indigenous movement to bring them back. The axolotl actually became a major symbol of indigenous resistance because of this movement
> the single most productive agricultural system humans have ever practiced
This is simply not true. The highiest maize yield per hectare I can find anywhere online for chinampas is less than half the 13.5 metric tons per hectare that farmers get in Iowa. The more reputable numbers are less than 1/4 of that. It's probably true that they were among the most productive pre-modern agricultural plots which is a great achievement, but there's no need to make things up.
I'm not being hyperbolic.
They produce a lot more than just corn. Not only can they be farmed for hundreds of years without break, but they can be harvested 4 to 7 times per year. They are 13 times as productive per unit of area as conventional dry-land farming.
> In Xochimilco, roughly 750 hectares of active chinampas produce around 80 tons of vegetables daily. This translates to a massive, continuous, year-round output of over 38,000 tons per year across the entire area
So that translates to 50.7 metric tons per hectre.
---
> the most productive pre-modern agricultural plots which is a great achievement, but there's no need to make things up
Post-industrial agriculture is not actually more productive per area. It's just more productive per input labor.
> Agricultural yields within the most densely populated and productive preindustrial land-use systems compared well with modern yields and were sustained in some regions for centuries to millennia, even though they also tended to require extreme inputs of labor and other socially unsustainable hardships
https://www.pnas.org/doi/10.1073/pnas.1217241110
That article you linked doesn't mention Xochimilco at all so I have no clue what you're quoting. I can't find a single source for your 80 tons claim (other than some blog post that cites another blog post), which if true and I suspect it isn't is 20 tons less per hectare than many conventional vegetables like cabbage and tomatoes. Other sources I found cite a number that's less than half of what you're claiming. Do you have a real source that isn't a blog post?
>Post-industrial agriculture is not actually more productive per area. It's just more productive per input labor.
This is alarmingly false. As I pointed out many conventional vegetables yield 100 tons per hectare today. Moreover yes they are more productive per unit of labor. The Mexica and their contemporary polities around Lake Texcoco were miserable slave societies that used armies of captured war salves (tlacotin) to perform much of the work. They also used unpaid corvee labor through the coatequitl system, and serfs known as mayeques. So honestly its quite the social advancement that we don't have to press people into agricultural labor at spear point anymore.
> Agricultural yields within the most densely populated and productive preindustrial land-use systems compared well with modern yields
The references for this quote are about South East Asian rice agriculture, which today is still done more or less done the way it was in premodern times. This quote doesn't support your argument and is at best deceptive.
How much fertilizer does the Iowan farmer need to add to their field to achieve that? How many years can they maintain that yield without eroding the soil?
Who cares? Fertilizer is nitrogen that literally comes out of the air. Erosion is vastly overstated by permaculture enthusiasts and can be mitigated vy changes to tillage and irrigation. Erosion in the Midwest clocks in at about 0.04 mm per year, but there's plenty of new soil deposition around the Mississippi. It's a manageable issue.
this is extremely wrong, but anyway back to my day because there is just too much wrong in this to respond to each wrong phrase
Extremely wrong how? There's a great an well sourced section in Vaclav Smil's How to Feed the World about this very topic. I also cited a specific erosion figure. But I guess that doesn't matter.
looking forward to reading it! definitely skeptical about your erosion rates, will have to go do my own research later (quick look, USDA estimates for the Corn Belt (~5 tons/acre/year on average)). if your info is coming from one book then i'm doubly skeptical, though i would bet that a soil scientist would probably agree with me and i'm def wondering if you might've misread the book?
i'm not a farmer, but i do manage woodlands, have a huge garden, volunteered on farms over the years, worked in a sustainable ag non-profit, and have even tried distributing sweet potatoes, etc, so i have an avid interest in agriculture and our food system.
aside from the fact that the soil is one of the three most important components for growing food, therefore it's extremely important to take care of it if we want our species to live into future centuries... there is a lot of evidence that shows that industrial ag creates erosion problems (one easy example: all of the national forests in my area was degraded farm land that they converted to woodlands in the 30s, because they learned this fact that hard way then). believing that hunger is a solved problem because of 20th century style agriculture is a fallacy. the dust bowl is one historical example that shows how this system can fail spectacularly, and it's all based in how we manage the topsoil, a natural resource just like oil or water.
we lost the moment we tried to overcome natural systems with chemicals (we've had a good run but i believe it's gonna be an anomaly in history). you can use science + natural systems in your favor to grow food. taking care of the topsoil is objective number one. food is a byproduct of good soil. the soil is a living system and chemicals kill that ecosystem to our detriment.
technology is definitely not the answer here. you are welcome to go try to grow food on mars without soil. good luck!
I initially copied the wrong number, the correct number is 1mm per year, coming from a Unas Amherst study not Smil’s book. It’s high vs pre industrial rates, but not catastrophic and as Smil points out there are plenty of places where land being farmed industrially is gaining soil.
How many years can they maintain that without petroleum inputs?
Ammonia can be generated through electrolysis as feed-stock for Haber-Bosch to get nitrogen, so literally forever. The reason we use petroleum is because it's currently cheaper than solar PV electrolysis.
How it was (a great interactive 3d reconstruction)
https://tenochtitlan.thomaskole.nl/
This is awesome, thanks for sharing.
Andrew Wilson, who works with the United Nations World Food Program, also made an in-depth minidoc on them: https://www.youtube.com/watch?v=86gyW0vUmVs
Wow this is amazing. Thank you!
Thanks to the author and HN - it was posted here sometime ago, and being that impressive it naturally stuck in my memory like i'm sure now it will in yours :)
[dead]
Contrary to the report, they are actually not difficult to keep as pets - they are just highly sensitive to pollutants in the water.
The unfortunate case for the wild population, is that they naturally inhabit a location which today has one of the highest human population densities in the world, and hence massive pressure on water resources. We could probably quite easily re-establish a breeding population in remote areas in Europe but would constitute an invasive species and hence wouldn't happen.
As a species, they are not endangered due to their very large populations now in the pet trade (though these then get inbred, become domesticated etc).
Axolotls have also been used for over 200 years for medical research related to regenerative biology. They’re unique among vertebrates in that they can regenerate nearly every part of their body, even parts of their brain. https://orip.nih.gov/about-orip/research-highlights/amazing-...
"in the wild" might be doing a lot of heavy lifting, or it may be based on subspecies or similar.
I don't really expect to find endangered species at the local pet store.
I have three axolotl's in the next room, there are no subspecies to my knowledge, except maybe for some cross breeding with Salamanders in the US.
They are common in scientific research as they have amazing regenerative abilities; they will often mistakenly bite each other's legs off as juveniles (they are not the smartest creatures) and then grow them back in a few weeks, good as new. They made it into the exotic pet trade and now they are quite common in captivity, but now critically endangered in the wild. There are attempts to breed and repopulate them, with some limited success.
Another interesting thing, in many countries and states it is legal to keep an axolotl and illegal to keep a Salamander.
They are actually fairly easy to keep in my experience, with two caveats. 1) you need to be able to keep the water below 24 Deg C, this means spending some money on chillers even in sub-tropical countries. 2) If you have a pair in the same tank (regardless of sexing) you need to be prepared to cull the eggs! (freeze them) Prices here went from ~$50NZ each down to around $10-15 each due to the Minecraft craze.
Why are salamanders illegal?
Because they burst into flame! 90% of wizard dwelling fires are caused by salamanders!
(in reality probably the law banning them as pets to protect them didn't include axolotls because the legislature didn't know they existed)
They're either an invasive species, and therefore should not be introduced to the area (and you know that many pets will be introduced once the novelty wears off). Or they're native to the area, and should be left alone because they're endangered or otherwise threatened.
Those are just two reasons, but I'd bet they cover a lot of cases.
Often Axolotls have been "grandfathered" into the legal exotic pet trade, and salamanders have not and they tend to be considered separate species, even though biologically it's a very blurry line. Also, it often happens in areas where there is a local wild salamander population that is being protected from poaching.
You likely don't have wild axolotls nearby so if a pet escapes it'll just die and not affect the ecosystem. OTOH, an escaped salamander might thrive and displace wild salamanders and disrupt the ecosystem. Or carry a disease, or ...
most places ban exotic pets that are able to survive in the local climate to prevent invasive species from outcompeting the local feral cat population.
my understanding is that thr light skinned / pink variants are the results of mutation and selective breeding - and obviously racism, light skinned being considered more cute - in the pet population and almost all examples in the wild are dark skinned.
Racism? Come on. A camouflaged pet you can't see in the tank isn't as fun as one where you can see all the crazy physical structures.
It's a similar story for Venus fly trap plants. It has a tiny habitat so it's exotic. They're easy to breed so it's cheap to start selling them. But their limited habitat is being destroyed, so they are endangered and also on the clearance rack at the garden store.
Why not. We found plenty of endagered species at zoos. They are endangered not only as a function of the number of species, but due to their vanishing environments.
It's a very strange definition. Would you consider domestic chickens "endangered"? Clearly if there are many kept in captivity and bred, there's little chance of them becoming extinct even if there are nearly none in the wild.
There is in fact a difference between domesticated animals and wild animals that are kept as pets.
Do you also find it strange that e.g. various wolves are/have been considered endangered even though dogs exist?
It's arguably different if it's the same species (wolves and dogs are considered separate even if cross-breedable) - and very few of the chicken breeds are found in the wild.
I suppose it's because we assume "endangered in the wild" means something that doesn't breed well in captivity and so is hard to reintroduce.
I believe all captive ones are cross-bred, so are distinct from the native species
the pet ones are almostly entirely captive bred so they are pretty distinct by now