With Greymoor, I we received something that seemed contradictory, and yet; actually solved a puzzle. In the various delves and locations in which chaurus can be found in eso; you may have noticed that there are large egg mounds, very similar to the ones we see in TES Skyrim... HOWEVER, unlike those egg mounds, the ones in eso spawn a single pale chaurus youngling, almost as large as the mound it came out of, already looking like a fully formed chaurus. Already, this doesn't seem to match with how many eggs can be held in one of those mounds... however, the amount of adult chaurus we actually encounter in-game in Skyrim seems to line up more with the single youngling emerging from the mound...

Now, if you paid attention to the falmer totems in TES Skyrim, you'll have noticed there are very small chaurus hatchlings that are used to adorn the totems, the centerpoint between the bones... roughly the size of your hand, rather round, and having not yet developed the long bodies of their elder counterparts (the beginnings of the tail and the head's jaws can still be seen, though). If they hatched like this, there would be many, many more chaurus we should see in skyrim, right? By all means, any cave inhabited by them should be absolutely swarming and infested by chaurus... So, what gives? Do chaurus hatch like the dead young we see on the totems in TES Skyrim, a bunch of them in a single mound, or do they hatch as young adults from an egg mound, with only one per mound? The answer, I believe, is a yes and a no: an in-between of these two ideas.

From what we can see of the egg mounds, particularly in TES Skyrim, is that there are a large amount of eggs in a single mound... and that the young, which are not interactable in-game but can be seen on the totems, are only the size of your hand... but when you take into account a SINGLE large youngling leaving the mound in ESO... a dark picture begins to emerge. It is very likely that many, many eggs are laid in a single mound, however... they grow up much in the fashion of various species of predatory birds and the like; the chaurus that is the first to hatch, either the oldest, or the strongest, once it hatches: begins to eat its younger siblings and the unhatched eggs in the mound. Eventually, when it has eaten all of its siblings, it has grown large and strong enough to emerge as a proper chaurus, and the single youngling emerges, already large enough to survive on its own and hunt for larger prey. This is actually quite a genius reproductive strategy, imo...

It's slow and steady; a process that ensures that at least one infant in every clutch lives long enough to reach an age where it cannot be easily predated on: safe and cozy with a long-lasting source of food in a sheltered mound until it's forced to emerge. In a way, it's a direct contrast to frostbite spider reproduction, which is either a boom or a bust. Frostbite spiders emerge from their egg sacs in great numbers, but are very small, about the size of a human hand, much like a hatchling chaurus. They can partially depend on the protection of their mother, but are more or less on their own... this kind of swarm-emergence method of reproduction is either very successful, or very disastrous, depending on the circumstances... a frostbite spider's entire clutch of eggs could end up surviving, which heavily increases spider numbers, or all its young can end up dying after hatching due to their very vulnerable age and size... The chaurus method, if my hypothesis is correct, is instead a slow and steady approach, that keeps chaurus numbers steadily rising, not nearly as quickly as frostbite spiders, but much more stably.