How do you know that black footed ferret main diet is prairie dogs?

The black-footed ferret (Mustela nigripes) is a critically endangered species of ferret found in North America. It is one of the most endangered mammals in the world. The black-footed ferret is a carnivore and its main diet consists of prairie dogs.

Here are some evidence to support the fact that black footed ferret main diet is prairie dogs:

* Stomach content analysis: Studies of black-footed ferret stomach contents have shown that prairie dogs make up the majority of their diet. In one study, prairie dogs were found to comprise over 90% of the black-footed ferret's diet.

* Habitat preference: Black-footed ferrets are found in close association with prairie dog colonies. They typically live in burrows that are abandoned by prairie dogs. This close association suggests that prairie dogs are a key resource for black-footed ferrets.

* Hunting behavior: Black-footed ferrets are known to hunt prairie dogs by entering their burrows and killing them underground. They are able to do this because they are small and agile, and they have a keen sense of smell.

* Predation risk: Prairie dogs are a major source of food for black-footed ferrets, but they also pose a risk to the ferrets. Prairie dogs are known to kill black-footed ferrets if they are caught above ground. This suggests that black-footed ferrets must be careful when hunting prairie dogs.