In 1996, Arizona become the fourth state to begin working toward reintroduction of black-footed ferrets to the wild. The reintroduction site, known as the Aubrey Valley, is a grassland community located in northern Arizona. Biologists with the Arizona Game and Fish Department work on the project year round and are stationed in the nearby town of Seligman. Activities throughout the year include daily care of ferrets in on-site acclimation pens and periodic spotlight surveys to look for released ferrets. Ferrets are bred in the spring and ferret dams raise kits in natural burrows within the acclimation pens, where they teach them to hunt prairie dogs. Some of the kits born on site are released. Others are retained for the next breeding season.

To find out what's going on in the field at Arizona's reintroduction site, check the Field Notes. These notes will have current project updates and information about black-footed ferrets.

November 25, 1998: Finding a black-footed ferret living in the wild is an exciting experience. During a recent survey, black-footed ferret 1NE98F5 was spotted ducking in and out of burrows, hunting prairie dogs. She has been observed on five different nights over the last two weeks. At only six months of age, 1NE98F5 is a fierce hunter and was released over a month ago. She was one of a litter of five females born on site in Arizona's first attempt to breed ferrets in acclimation pens located on the release site. Since her release, she has settled into an area within a large prairie dog town called "Pica Camp".

Black-footed ferrets are surveyed by searching from vehicles or on foot with powerful spotlights. The observer scans the survey area all night long looking for a small pair of eyes that will reflect like green headlights when located with the spotlight. When the green eyes are spotted, the first step is to determine if they actually belong to a black-footed ferret because other animals like coyotes, gray and kit foxes, and badgers have green eyeshine too. If the animal is a ferret, we can determine which ferret it is with the help of a PIT tag reader. The PIT tag reader consists of a "coil" which is ring-shaped, and the reader which has a digital screen. Before a ferret is released it gets a tiny transponder chip, only about 15mm long, implanted under the skin of its neck. When we locate a ferret, the PIT tag reader is placed at the burrow, with the coil over the opening. When the ferret looks out through the ring on the burrow, a nine-digit transponder number shows on the reader's screen and we can look in our records to see which ferret we've found.


November 27,1998: The last time 1NE98F5 was observed she was looking out of a burrow that had a long dirt trench extending out nearly five feet. She may have been cleaning the burrow, or perhaps she was digging through a plug of dirt to get to a hibernating prairie dog. I've seen pictures of ferret trenches in books, and occasionally I'll find a trench dug by one of the ferrets in the acclimation pens, but this was the first trench I'd ever seen in the wild. It was beautiful.

A trench is one of the few observable signs in the wild that indicates a ferret is present. It is formed when the ferret backs out of a prairie dog burrow, pulling dirt out with its front paws and kicking the dirt behind with its back legs. Each time the ferret pulls the dirt farther away from the burrow in this manner, a depression or trench is formed in the fresh dirt.

November 29, 1998: Cold and blustery, 98% cloud cover, winds about 25mph. Today I saw a Northern Harrier (Circus cyaneus) patrolling low over the ground as they typically do. Harriers are commonly seen in the valley during the winter months, drifting just a few feet over the curves and rolls of the land, hunting for smaller birds and rodents. Their characteristic gliding flight, along with the white band on their rump, makes them easy to identify.


December 12, 1998: On my way out to the valley to feed the ferrets today I saw two Loggerhead Shrikes (Lanius ludovicianus). Loggerheads are one of my favorite birds because of the sharp contrast of their black mask, wings and tail to their light gray body. These predatory birds leave their "calling cards" all over the valley on barbed wire fences, cactus spines, and stray wires on the ferret pens. They hunt grasshoppers and small lizards and cache them away by piercing them through the points of the spines and barbs. In the cold months, when grasshoppers and lizards are not active, the shrikes eat the food that they have stored.

January 8, 1999: Sunny and pleasant, no wind. When I have the will to resist hitting the snooze, I am usually rewarded. A little extra sleep is really not worth missing the sights and sounds of an early morning. The 20-mile daily drive out to the Aubrey Valley to feed the ferrets is a good opportunity to see hawks, kestrels, and other wildlife associated with a grassland ecosystem. Just after rounding Chino Point and heading northwest toward Aubrey Valley, I saw two Coyotes (Canis latrans) trotting along toward the Aubrey Cliffs. A few miles down the road I saw a small flock of Western Meadowlarks (Sturnella neglecta), an American Kestrel (Falco sparverius), and a Ferruginous Hawk (Buteo regalis). The big treat was seeing the Bald Eagle (Haliaeetus leucocephalus) that was sitting on a fence post about a quarter mile off the road. I could easily see its white head and that tells me that it is at least four or five years old. Younger balds have dark brown plumage on their heads. Each winter, a small number of Bald Eagles spend a few months in the valley, and this is the first one I've seen this year.

February 7, 1999: Partly cloudy, light winds from the south. Ferret 2549, a nine month old female, is one of 24 ferrets in our pens right now. Breeding season is approaching and it'll probably be less than two months before 2549 gets an opportunity to be a mom. The breeding season for Black-footed Ferrets generally starts in March, and most litters are born by June. A female's gestation period usually lasts 42 days, and her average litter size is four or five. Black-footed Ferret kits are pink, hairless and only about two inches long when they are born.

Even though she's so young, 2549 can have her first litter during her first year. She's spunky, mischievous and seems like she'd make a good mom, or dam. Today she was up to her usual tricks. Every time I fill her water bowl she immediately grabs it and pulls it over to her burrow, as if she wants to take it down the hole with her, dumping the contents completely. A little later I was throwing large tumbleweeds out of the pen and when I looked over I saw her jumping around, hunching her back and shaking her head. She would prance boldly in my direction on the tips of her toes and then trip all over herself trying to get back to the safety of her burrow. Then she would jump up and twist around and bite at her hind leg. It is pure entertainment to watch a ferret engage in this kind of play, and I couldn't take my eyes off of her. She kept this up for two or three minutes and then retreated to her burrow.

February 17, 1999 The first Gunnison's prairie dogs (Cynomys gunnisoni) have come out from hibernation. I saw about two dozen on my way out to feed the ferrets today sitting, like buddhas, with perfect posture and rounded bellies facing the sun. The warm rays must feel really good after over 3 months of sleep, deep underground.

March 10, 1999 Soon we will start examining females on a weekly basis to determine their reproductive status. To make this process a little less stressful on the ferrets (and the field crew), each female will be placed in a nest box and cage set-up within the preconditioning pen where she will remain through gestation and whelping. The set-up consists of a wooden nest box that has been buried so that only its top doors are exposed. A black tube provides a connection from the nest box to an above ground cage where the ferret can get her food and water. Over the top of the nest box is a wooden pallet covered with a plastic tarp to keep the sun from beating down on the box and to protect it from the occasional rain shower.

March 20, 1999 Today 14 of 18 females were trapped and checked to see if they are showing signs that they are starting the estrus cycle. The check takes less than five minutes, only a minute and a half if you have a cooperating ferret. Most go right into the handling cage, but others resist every time. Like fitful children they go limp or hide under the wood shavings at the bottom of the nest box. Once in the handling cage, each ferret's weight is recorded, and her overall appearance is noted. Then we check for external parasites, such as ticks or fleas, and record the vulva measurement. If the female's vulva is 4mm X 6mm or larger we will do a vaginal wash, which involves flushing a minute amount of sterile saline into the vulva, drawing it back out, and then aspirating it on a slide. The slide is later stained and viewed under a microscope. The slide indicates when the female is most ready to be paired. Females who are paired too early are less likely to become pregnant.

March 22, 1999 Saw a pair of Burrowing owls (Athene cunicularia) today. My favorite owls; they look so comical on their long legs, standing on a prairie dog mound. Like many birds, Burrowing owls are monogamous. The male, with some help from the female, makes a nest in a burrow that he lines with cow chips (plenty of those out here), horse dung, food debris, dry grass, weeds, and feathers. The female usually lays 7-9 eggs in the burrow, and she incubates them for 21-28 days. During this time the male feeds the female. Once the young hatch, both the male and the female feed them. As I drove by, this couple was bobbing their heads up and down deeply -- like they were taking bows.

April 1, 1999 A late winter storm is making its way through Seligman and the Aubrey Valley. Exactly like last year on the first day of April. The temperature was only about 39 degrees at 1:30 this afternoon, and the low last night was 24 degrees. Today I saw two Ferruginous hawks, two Loggerhead shrikes, a Golden eagle, a Northern harrier, and I couldn't count all the American kestrels, they seemed to be on every telephone pole and wooden fence stay that I drove by.

April 2, 1999 This morning there was probably about five inches of snow on the valley floor from yesterday's storm, but by noon it was gone except for the shady spots under clumps of Snakeweed (Gutierrezia sarothrae), a shrubby odorous plant whose presence is indicative that the land has been overgrazed. I checked on the females who are confined to nest boxes and found them to be dry and unaffected by the melting snow.

April 17, 1999 No wind, sunny and warm, 86 F. Today I saw a very pretty American badger (Taxidea taxus) sitting at a burrow, watching me as I nearly drove by. I stopped and got a couple pictures and then walked over to the burrow to try to get a close look, and maybe a lucky picture of it looking out from the burrow. He ducked inside as I got close, and all I could see was the dust rising from inside the burrow as he dug in deeper, out of my view.

April 25, 1999 After staining and reading 20 slides I found that five females need to be paired in two days and two others will probably be ready by the end of the week. Staining the slide provides a means to determine when the female is most ready to be paired with a male. The staining process gives the cells (collected in the vaginal wash) color, and under the microscope they look like a kaleidoscope of blue, pink and orange geometric shapes. Once a slide is stained, it is viewed under the microscope and the highly keratinized superficial cells (orange cells that have lost their nucleus) are counted to detemine their percentage compared to the other types of cells. As a female gets closer to estrus, more and more of her cells change, and will eventually appear on the slide as orange and anucleated. With only 7 males available to pair with 18 females, I just hope the females don't all go into estrus at once.

April 27, 1999 There was so much to do today that I was in a rush, bouncing along the two-track road that cuts through the valley to the pens. I did take time out to stop and watch the largest badger I've seen run and dive into a burrow. At first I thought it must have been a coyote, it was moving so quickly and seemed to be too large to be anything else. But with my binoculars I could see that it was in fact a very large badger. Five females were due to be paired today. First, male 2510 was trapped and transported to pen 2 to be paired with 1358. The standard pairing procedure is to trap the male and transport him to the female's pen section. When we arrive, the female usually comes up out of her nest box to see what's happening. I like to make sure the two see each other, so that when the male is released into her set-up his presence isn't a total surprise. Next, the female's cage door is unlatched and the handling trap is opened to let the male go into her cage. The first thing that usually happens when the two ferrets are paired is they run back and forth from the cage down into the nest box a couple times. One or both of them will hiss, and sometimes the female will cry out as if in fear or surprise. One sound we listen for is dove-like cooing that seems to be a good indication of compatibility. If no fighting occurs within the first several minutes of pairing, we take this as a sign that the two are compatible and leave them together for three days. After separating the two, the male is not paired with another female for three more days. The five pairings were pretty uneventful overall. It was difficult to hear any potential cooing with the wind gusting like it was. Everyone seemed to be compatible, though male 2485 was more interested in receiving his food than getting acquainted with 1905.

May 12, 1999 Sunny, clear and warm, light breezes out of the south. Pen maintenance was the major item on the agenda today, picking up tumbleweeds that have blown up against the sides of the pens. Usually not a very exciting job, but today I picked up an armful of the brittle Russian thistle and found a Mojave rattlesnake (Crotalus scutulatus) coiled underneath. The sudden adrenaline surge I experienced was more potent than any double cappuccino I've had. Rattlesnakes command absolute respect. At this time of the year, sightings in the road and near the pens are pretty common. I worry more when I don't see one, potentially overlooking a cryptic body. They generally don't rattle until you're uncomfortably close, but I've never had one strike at me (knock on wood). I try to remind myself each morning to be mindful where I step. Two years ago I was gathering four Tomahawk traps which had been used to catch prairie dogs for feeding ferrets. I had two traps under my left arm and I carried the other two in each hand. When I set the traps down next to the vehicle to open the door, a small 1.5-foot Mojave rattler slithered out from under one of the trap peddles. It still gives me the heebie-jeebies to think of that snake, so close under my arm.

May 20, 1999 Shortly after getting back from the valley I got a phone call from Tim Pender, the local Wildlife Manager, saying that a railroad worker had discovered a Golden eagle (Aquila chrysaetos) that was injured near the railroad tracks about 14 miles west of town. Tom Silvia and Jennifer Cordova, who also work on the ferret project, went out to the area to try to find the bird. They located the eagle, which barely put up a struggle as they placed it in a large box and transported it back to the field station. I tried to contact two licensed wildlife rehabilitation workers, Sandy Cate and Christie Van Cleve, for advice on treatment options, and to make arrangements to get it to a rehab facility. In the meantime the eagle, an immature female who appeared to have recently lost her left eye, stood in the box with her head bowed to her chest. Her lethargic, lackadaisical behavior indicated that she was dehydrated and in need of medical attention. She made a feeble attempt to resist as we put a hood over her head and lifted her out of the box to give her subcutaneous fluids. As a precaution we also put velcro straps around her feet, to secure her talons which were a potential threat despite her weak condition. I warmed up a bag of lactated ringers and administered 70 cc's of the fluid into each leg, just under the fold of skin of her inner thigh. From the poor overall appearance of her plumage we could tell she was in pretty bad shape, and had obviously not been caring for herself for quite some time. After getting the fluids in each leg, we put the eagle back into the box, but by then she would only lay face down. We weren't sure if she was going to make it, but the best chance was to transport her to a rehab facility for more specialized care, which Tom did later in the evening.

May 28, 1999 Called Christie Van Cleve today to check on the Golden eagle. She is going to make it, although she is blind in her left eye from her injury. She has a healthy appetite, and although she has lost most of her feathers from the stress of her ordeal, she is doing fine overall. Usually a bird can adjust to life with only one eye, but this eagle seems to have suffered head injuries that would prevent her from making it on her own. She will probably be placed at a holding facility where she might be used as an educational bird.

June 4, 1999 The first kits have been born. Two litters, 10 kits total. Female 2535, a one year old, had a litter of 6 and 1494, a four year old, had a litter of 4. The kits are tiny, only about two inches long. Their high-pitched cries sound like baby birds. The dams are very protective. When I went into 1494's pen and approached her set-up I knew I was in for a treat because she didn't come running up to the cage door for her food. She hasn't run up to the door for a couple days actually, but today she took nearly a full minute to appear. She finally poked her head out of the tube that leads down into the nest box and she looked a little ragged. I lifted the shade pallet and unlatched the nest box door to take a quick look. Four pink bodies were squirming in the shavings, with mom standing over them protectively, a long low hiss told me not to invade her space.