Fun read! It still surprises me no predator has been able to somehow take advantage of this evolutionary gap. You'd think one of the predators mentioned in the article would evolve a different way to the detect them.
Then again, something similar probably happened many times in evolutionary history, and the victim species died out as a result. So if one of those predators would exist, we wouldn't have sloths. I guess this leaves them vulnerable to invasive species?
The article also mentions that they have relatively little muscle mass, so maybe it is more rewarding to catch say a regular monkey rather than a sloth.
Evolutionary traits usually come with a tradeoff, and if a predator evolved to be able to catch sloths more easily it might make them less able to catch the juiciest prey, so overall it might be more worthwhile to focus on the other animals and leave sloths off the table, so to speak.
It's not like they never get eaten by predators, as the article says. It's only that they need ot shift the balance far enough in their favor to not die out, like by improving camouflage.
I do not understand the downvotes. I watched a half-meter-wide snapping turtle spend all day trundling its way to the water this spring. It looked like one of those world war 1 tanks.
Of course, it had the armor of a tank and a 20 cm neck with a bolt cutter for a mouth.
Then again, something similar probably happened many times in evolutionary history, and the victim species died out as a result. So if one of those predators would exist, we wouldn't have sloths. I guess this leaves them vulnerable to invasive species?