oxen

The polar bears pop up from their winter lairs, the arctic tern soar back from their long journey south and the musk oxen wade north.

In a newly published large study from Greenland musk oxen have been followed for 25 years to see how their feeding habits affect their reproductive success.

So how did the researchers show how the chemistry of the ground affects the reproductive success of the musk oxen?

They needed to know where the musk oxen were at different times.

Also, every summer a field crew of researchers perform visual counts of all the musk oxen they find in the area and make a note of how many adults, males, females and calves they see.