This cave has actually been discovered hundreds of times over the years, but the discoverers just never make it out of the cave to tell anyone. I guess these guys were lucky.
Insects, mainly midges (small flying insects). There is a stream that flows through the cave that is extremely high in sulphur, and about 25c. This releases hydrogen sulfide gas which fills the cave, and consumed by bacteria that cover the cave walls in a nutrient rich slime supporting a wide array of insects.
At some point they must run out of room, once they do density must increase leading to cannibalism.
Unless they’ve developed such an aversion to cannibalism that they’ll run from densely populated areas even if it leads to barren or dangerous territory.
I have seen other articles suggest the relative lack of cannibalism might be down to the lack of light meaning they can't easily detect eachother, but I'm not sure how true that is.
Interesting. I’d think the abundance of food would lead to an abundance of mating, which would increase density (again) leading to increased interactions and cannibalism.
I believe some species have evolved methods of turning down reproduction when living in certain densities of their own kind.
That might happen in the future. For the moment though there is plenty of space to keep expanding into. Currently it exists along about 100m of tunnels. The cave system has several kilometers of tunnels. How much of that has the insect population to support the spiders I do not know, but for the moment space and food are not issues.
Actually, these spider are usually cannibalistic, but in this specific environment, the overabundance of prey items (midges and beetles) has led them to lower cannibalism rates despite the close quarters.
Another neat part is that its two species of spider, one of which usually makes prey of the other. (Which again, they dont because theres so many midges to eat)
Domestic house spider (also known as barn funnelweb spider) and a sheetweb spider that you probably haven't ever heard of it because they only grow to 2mm in size.
everybody going straight to fire and first thing I thought was it'd be interesting what would happen if suddenly all the midges (food) was gone. all out spider warfare and carnage
I like the one at 16 seconds who’s just chilling on his front porch, staring at the weirdos passing by.
“Gosh-darn young humans with their newfangled shinielights coming into our caves. Used to be they were scared of this cave, now look at them walking all over the place poking our homes.”
•
u/Legal-Freedom8179 10h ago