The blind, eel-like amphibians called olms live deep in European caves and can go years without food
Balázs and his colleagues began studying olms in the caves of eastern Bosnia-Herzegovina more than ten years ago. After several dives, the researchers began to suspect that some olms hadn’t budged. In 2010, the researchers labeled seven olms, and in 2016 tagged an additional 19. Each time they recaptured an olm, they tracked how far it had moved since the last time they saw it.
Out of 37 recaptures over the full study, only three olms moved further than 65 feet, and one olm was found in the same spot for 2,569 days, or just over seven years.
Olms live in cave systems without much food, and they can go for months or years without eating, writes the Independent’s Harry Cockburn. The animals also aren’t particularly sociable—they only mate about once every 12 years—and have no predators. The crustaceans and snails that olms snack on are both scarce and evenly distributed in their caves. It appears that if olms won’t benefit from moving, they just don’t, as Matthew Niemiller, a cave biologist at the University of Alabama in Huntsville who wasn’t involved in the study, tells Science News.
Olms are listed as vulnerable species because they have a small, specific habitat range that’s broken up over many cave systems. They’ve caught the attention of naturalists from Charles Darwin, who called them “wrecks of ancient life,” to David Attenborough, who included them in his list of ten species he would most like to save from extinction.
https://www.smithsonianmag.com/smart-news/cave-dwelling-salamander-didnt-move-7-years-180974233/