Front Range Colorado Naturalist: Black-Footed Ferret

Mustela nigripes

Here is another blog where I will not be able to use my own photos, for alas I have only a few bad pictures of a pair in a museum in Fort Collins but nothing very usable.

I will hopefully give everyone the correct credit for the photos I use!

HISTORY:

The Black-footed ferret is one of the most endangered mammals in North America. Once numbering in the tens of thousands, its numbers have been decimated to less than two percent of its original range. It is North America’s only ferret (the domesticated ferret is a kind of European ferret).

When I went to Fort Collins Museum of Discovery I learned that the Black-footed ferret had been thought to be extinct, and they nearly had been.

The last time it was thought they had gone extinct, the black-footed ferret was rediscovered by none-other-than someone’s pet dog. The dog had dutifully brought the dead black-footed ferret home to its owner, and the curious owner brought it to a local taxidermist to figure out what the animal was that his dog had brought home.

When it was discovered that it was the thought-to-be-extinct black-footed ferret, it made big news! Scientists found the last patch of these ferrets and watched the 120 animals, the last of their kind. They studied them, learned everything they could from just observing these resilient animals.

But then something terrible happened. They started dying. All of a sudden their numbers started plummeting, as a disease was killing off the last of these ferrets. Scientist argued whether or not this was a sign, they were thought to have been extinct before, should they let nature take its course?

Happily, it was decided that they intervene and they rounded up what was remaining of the black-footed ferret. Of the 120 that originally made up this last pocket of black-footed ferret, only 18 were left at this point, and not all of these were breedable.

For those of you who understand genetics, this means there was a HUGE genetic bottleneck...the best way to explain this is to imagine if all of a sudden there were only 30 people left in the world. They all happen to be white, but have some hair color variation like blonde hair, brown hair, and black hair. By only having 30 people to repopulate the planet, there would be a huge loss in diversity. Only one kind of skin color, three colors of hair, so on and so forth. Over time, there will be more variation, but at first, there is very little.

A genetic bottleneck of this size means that the next generation is almost clones of the first, with little variation between them. This makes it harder for them to adapt and thrive.

Nature.com describes the definition of a genetic bottleneck as: A population bottleneck is an event that drastically reduces the size of a population. The bottleneck may be caused by various events, such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms.

Because of this genetic bottleneck, current black-footed ferrets have lost immunity to diseases that their ancestors would have been immune to. They can even get diseases from humans, so scientists have to be very careful around them during the black-footed ferrets repopulation process.

Lately black-footed ferrets have been released back into their ancestral habitats, most recently in Soapstone Prairie Natural Area in Fort Collins, Colorado. http://www.fcgov.com/naturalareas/finder/soapstone

The Fort Collins Museum of Discovery is the only museum in the world to have black-footed ferrets, and they have two. They are Mr. Brightside and June, two retired breeders who now spend the rest of their lives relaxing in the museum. They are too old and not healthy enough to be released back into the wild.

In the wild, black-footed ferrets can live from 1-3 years, and in captivity they can live up to nine years. Mr. Brightside is 6 years old and has chipped teeth, and June is 5 years old.

Today, there are 500 living in the wild and 300 in the captive breeding program.

HABITAT AND DIET

Sometimes called the prairie bandit, the black-footed ferret lives in the short grass prairie in prairie dog villages. You might think it’s nice of the prairie dogs to share, but they don’t share willingly. The black-footed ferret’s main prey is the prairie dog. In fact, prairie dogs make up over 90% of the black-footed ferrets diet.

The black-footed ferret might look cute and cuddly, but it is a voracious and fierce little predator. A single ferret could eat more than 100 prairie dogs in one year, and will sometimes eat the occasional ground squirrel, rabbit, small rodent, or even bird.

Because the black-footed ferret is so reliant on the prairie dog, prairie dog colonies must be large and healthy to support a black-footed ferret.

Their range used to extend from Southern Canada to Northern Mexico all across the great plains.

A black-footed ferret is dragging a prairie dog into its burrow.

BEHAVIOR

Black-footed ferrets are nocturnal, and spend most of their time underground. This means it is a rare treat to see one, and you should appreciate the rareness of such a sighting!

They live in abandoned prairie dog holes (no prairie dog would keep them as a roomie!)

They hunt prairie dogs at night, and strangle the bulkier prairie dogs with their teeth while the prairie dogs are sleeping. Not so cute and cuddly now, right?

REPRODUCTION

The young are called kits, and are born blind and covered in thin white fur. They remain underground until they are two months old. The females raise the kits alone, and by October the young are mature enough to be independent and they go off on their own. They are solitary animals and only come together to breed.

The mating season is from March to April, with a gestation period of 41-43 days. This means the kits are born around May or June. They will have 3 to 4 kits on average.

FUN FACTS

A group of black-footed ferrets is called a business
Thought to be extinct in the 1970’s, was rediscovered in 1981
The last wild population was in Meeteetse, Wyoming. It was plague that nearly brought this last business of ferrets to become extinct.
The vocalizations of the black-footed ferret are chattering and hissing.
Sometimes called the Prairie bandit because of its black mask
The domesticated ferret is of European origin and has been domesticated for hundreds of years. A black-footed ferret is a wild animal and will not make a good pet.