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.
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
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
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.
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.
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> 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
>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.
> This is alarmingly false.
I'm sorry but I can't take your comment more seriously than a paper published in a respected journal that has been cited 1,099 times. It provides 4 sources to back up the claim I posted.
In scholarship on land use history this is pretty well accepted.
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As for the specific chinampas yields, such high yields shouldn't be surprising when you have 4-7 harvest per year and require no periods of being fallow.
The UN's FAO provides more specific breakdowns on yields on page 22 of their report
https://openknowledge.fao.org/server/api/core/bitstreams/cd8...
You're have to download it but the designation also has more specific figures
https://openknowledge.fao.org/items/ba8d198e-a18b-4541-b94b-...
> It is clear that the yield per crop varies depending on the species and variety sown. However, in the case of the chinampas, yields are between 10 to 15 tonnes/hectare. An average of 12.5 tons/ha
That's not 80 tons per hectare as you stated.
> I'm sorry but I can't take your comment more seriously than a paper published in a respected journal that has been cited 1,099 times
You took the quote out of context, it's about rice agriculture in South East Asia, not Xochimilco. I check the citations and you obviously didn’t.
You are blatantly making things up here and trying to back your bullshit claims with papers that you are misrepresenting.
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!
> and as Smil points out there are plenty of places where land being farmed industrially is gaining soil.
i would bet at least $100 this happens where they do cover crops and actually manage the soil as a resource to be preserved
Herbicide is a whole different discussion and probably too deep a rabbit hole so far down thread.
[1] https://nebraskacorn.gov/cornstalk/corn101/what-is-no-till-f...
> 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.
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).
I don't really expect to find endangered species at the local pet store.
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.
(in reality probably the law banning them as pets to protect them didn't include axolotls because the legislature didn't know they existed)
Those are just two reasons, but I'd bet they cover a lot of cases.
Do you also find it strange that e.g. various wolves are/have been considered endangered even though dogs exist?
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.