feet long by thirty-two feet wide, were erected directly into and onto the prairie. Prairie dogs captured on local cattle ranches were brought in by the hundreds, quarantined, killed, gutted, organized into individual plastic bags, and frozen for a year’s worth of ferret food. Valerie had already established a colony of more than one hundred hamsters housed in metal bins in a nearby garage bay that would be used to feed young kits and train them to kill live animals. This was a gentle introduction to predation, as the small puffball hamsters were less likely to hurt young naïve kits than would the larger prairie dogs with strong jaws and razor-sharp teeth.
The delicate cycle of captive breeding began in earnest in March, when we became novice reproductive physiologists. Pairing normally solitary male and female ferrets together for extended periods of time can be dangerous. Long canines and muscles built for taking down prey nearly twice their size when used on each other can result in severe injury or even death. Thus, we carefully monitored the precise timing of when individual females entered estrus, using pipettes of water and microscope slides to perform vaginal washes. Counts of more than 90 percent of cells being keratinized indicated that a female should be ready to be bred successfully. We then placed a sexually active male with the female in an outdoor nest box for three days, hoping they didn’t instantly fight and listening for a struggle in the plywood box as we shut the door.
Following a pairing, we rested the male for three days prior to pairing him again with another estrus female—allowing his seed to restock. We similarly let the female rest, conducting an additional vaginal wash seven days after the initial pairing to determine whether ovulation had occurred. Given that all black-footed ferrets give birth around six weeks post-conception, using this initial pairing date we were able to fix the time when the females were likely to give birth or whelp.
Using this recipe, by June 2002 we produced eight litters totaling thirty-four kits. Thirty-four pinky-finger-sized young with their eyes closed wiggled in a pile of thin fur and pink skin. We left them alone in their indoor whelping boxes with lids closed tight. Just as we were nervous in pairing males and females, we were nervous of the mother rejecting or killing her young. To avoid tipping them into an infanticidal killing frenzy, we kept disturbance to a minimum; at first we opened a nest box lid only to change the bedding every five days. Despite this sensitivity, by July we had lost three kits. Two of the kits, when found, had been largely cannibalized by their mother. Was it a natural death of the kit and the mother simply ate the available carrion, an instinct to take what she could get to continue producing milk for the others? Or was it confusion by the mother, and infanticide as we had feared? Elsewhere in the animal kingdom the non-nurturing urge to kill off another mother’s kits to limit competition is fairly common. In this strange captive setting, did she not realize the kits were her own? Whatever the reason, with so few litters to raise, we hoped it was an isolated event. In another nest box, where one kit appeared to have died from an airway blocked by eating a small square of cardboard bedding material, we blamed ourselves.
• • •
By August, when the kits were well along toward feeding for themselves, Valerie and I began to alternate weekends off and I visited my parents, who had recently relocated for work at the newly created U.S. Geological Survey Northern Rocky Mountain Science Center in Bozeman. My father and I took my mother out to dinner for her birthday. Bad Thai food at a strip mall still tasted good because it was the first restaurant meal I had in a long time. I was at home, but I still felt restless without the ferrets to care for. They had become my crutch, my reason for leaving J, the only justification for a life away from a woman who loved me. I needed something, anything to give me a home, a peace of mind that reaffirmed that I was living a useful life and that I was not just passing through a cycle of travel trailers and temporary jobs. I needed something to give me traction when all idle thoughts seemed to slide toward loneliness. In an act of desperation, I went to the dog pound and adopted a red heeler, named her Abby, bought a sack of dog food, and headed back north to the Hi-Line.
FIGURE 5. Prairie dogs captured in live traps for transport.
When I got back to Malta on a Sunday evening, Valerie had left me a message that an entire litter of six kits died over the weekend. I wondered how, why, and if somehow I was to blame for taking two days off. We shipped the bodies down to the Wyoming State Veterinary Lab in Laramie, uncertain of what went wrong and anxious for the results. We worried that other litters could similarly collapse, so we once again cleaned the cages and disinfected the building, only with a new vigor. In the end, however, we could only leave the mothers to rest and care for their young.
Resigned to the will of the ferret mothers, we knew we could not disturb them with more attention, so we buried ourselves in the work of trapping prairie dogs for ferret food north of Malta. Saving the landowner the time and money of poisoning prairie dogs, in a single week we collected 516 individuals and placed them in elevated cages in an old tin shed with a concrete floor for a two-week quarantine. That was the set period of time during which a disease such as sylvatic plague would have run its course, and if they survived we could reasonably declare them disease-free ferret food.
While the prairie dogs were in quarantine, we spent the following weeks preparing the outdoor pens for ferrets. We checked for breaks in the first or second level of our fences that kept the ferrets in and predators out, and measured the voltage and cleared grass away from the electric fence wires strung to keep raccoons, skunks, badgers, and any other ground predators from climbing into our compound. Within each pen, we blew smoke from smoke bombs down into burrow systems with a leaf blower to check for escape burrows and filled in any breaches with gravel or concrete. We trimmed the grass down to the ground to resemble the closely cropped vegetation of a wild prairie dog town in the dry, clear days of midsummer. Last, we scrubbed out underground nest boxes that we hoped ferrets would use to spend the daylight hours and thus allow us to easily trap them for checkups. The nest boxes also made it easier for us to clean out their feces to prevent bacteria buildup and infections and to remove the accumulation of prairie dog fragments that attracted blow flies. These small flies were the bane of animal caretakers because on any scratch or wound they would lay eggs that would turn into flesh-eating maggots that burrowed just under the skin of our little brood of multi-thousand-dollar animals.
Once the prairie dogs passed quarantine, we selected a lucky few to pretend again to be wild and free. We released two or three into each cleaned-out pen to excavate the old burrow systems, performing prison labor outdoors after two weeks in a suspended square metal cage. Previously, the only boundaries for these animals were social divides between families on flat prairie. A lifetime of only imagined boundaries was replaced by real boundaries and confinement with strangers. I watched the selected few prairie dogs quickly readjust to the view of the sky, taste of fresh grass, and feel of dirt between teeth and toes. I silently urged them to enjoy their time in this semi-captive state, perhaps even escape, wishing I could relate to them that they had only a few days before they were to be recaptured and soon after butchered and put to use as ferret food along with the rest of their captive cohort.
While the captive prairie dogs were declining toward a feeble state on a diet of dried grain and alfalfa pellets, the ferret kits were getting feisty and outgrowing their indoor plywood boxes. Despite their size, which nearly equaled their mothers’ so that the nest box was crammed with writhing bodies, we stuck with Paul’s strategy of keeping families intact and indoors until fifty or sixty days after birth. We defrosted prairie dogs from our line of large chest freezers, quartered their bodies, and fed the torsos to the females and kits that devoured the tender, marble-sized dark red organs inside. I left the tougher hind legs for adult males that sat alone in their pens, useless until the next breeding season.
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