What Kills Lambs?

Here’s an easy research project.

There are lots of sheep in New Zealand, but no fox or any other large predator except pet dogs. What is the percent lamb mortality?

There are lots of sheep in Tasmania, but no fox or any other large predator except pet dogs. What is the percent lamb mortality?

There are no fox or any other large predator except pet dogs on many of the Scottish islands (Hebrides, etc.). What is the percent lamb mortality? There are no fox or any other large predator except pet dogs on many of the English islands (Isle of Man, etc.). What is the percent lamb mortality? 

Google will give you quick answers. Report out what you find.