Cave contents. Credit: Trond Klungseth Lødøen.
Researchers have uncovered a vast animal community dating to 75,000 years ago in a Norwegian cave.
Bones of 46 different taxa (from 33 species) were discovered at the site and represent the oldest example of an animal community in the European Arctic during what was a warmer period of the last ice age. Studying this ancient ecosystem could shed light on how wildlife responded to dramatic climatic shifts.
Animal bone fragments. Credit: Sam Walker.
The cave is located on the coast of northern Norway near the village of Kjøpsvik.
Findings from the dig are presented in a paper published in the Proceedings of the National Academy of Sciences journal.
“These discoveries provide a rare snapshot of a vanished Arctic world,” says first author Sam Walker from Bournemouth University, UK and the University of Oslo, Norway. “They also underscore how vulnerable cold-adapted species can be under changing climate conditions, which can help us to understand their resilience and extinction risk in the present.”
Among the bones are those belonging to 23 types of bird, 13 types of mammals and 10 types of fishes.
Birds included auks, ducks, a raven, kite, buzzard, crane, finches and a type of grouse called a rock ptarmigan. Mammals included hares, bowhead whale, blue whale, polar bear, porpoise, seals, walrus, reindeer, grey wolf and arctic fox.
Polar bear bone. Credit: Trond Klungseth Lødøen.
The team also found bones from the small mammal, collared lemmings. This species is now extinct in Europe. This is the first time it has been found in Scandinavia.
“We have very little evidence of what Arctic life was like in this period because of the lack of preserved remains over 10,000 years old,” says senior author Sanne Boessenkool from the University of Oslo. “The cave has now revealed a diverse mix of animals in a coastal ecosystem representing both the marine and the terrestrial environment.”
The variety of animals suggests that the area was largely ice-free during this relatively warm period of the last ice age when glaciers had melted across the Arctic.
Freshwater fish remains suggest there were lakes and rivers.
But these prosperous times appear to have been short lived. Whole populations likely died out when the glaciers returned and prevented them from migrating to warmer ecosystems.
“This highlights how cold-adapted species struggle to adapt to major climatic events. This has a direct link to the challenges they are facing in the Arctic today as the climate warms at a rapid pace,” says Walker.
“The habitats these animals in the region live in today are much more fractured than 75,000 years ago, so it is even harder for animal populations to move and adapt.”
“It is also important to note that this was a shift to a colder [climate], not a period of warming that we are facing today. And these are cold-adapted species – so if they struggled to cope with colder periods in the past, it will be even harder for these species to adapt to a warming climate,” Boessenkool warns.