Capturing Deer in Mojave National Preserve

Last week I had the opportunity to go to Mojave National Preserve and learn about capturing deer. They are in the second year of a ten year  project to learn more about where mule deer go in the preserve and what water sources they use. This year, 30 deer were slated to be captured and outfitted with radio- and satellite-tracking collars. 

The project involved a lot of people: the National Park Service, California Fish and Game, University of Nevada-Reno, and University of California-Davis. We started with a safety briefing and a description of the overall project. We were also assigned tasks. Some people have been doing this for decades, while others are brand new. I was assigned to one of the deer processing teams.

To capture the deer, the gunner uses this specialized net gun to shoot a net from about 20 feet over a deer while hanging out of the helicopter. There are lead weights on the four corners of the net, which ensure that it billows out to be more likely to trap the deer.

Here's the helicopter in action, with the gunner out on the skids. The mule deer were most often found near juniper or joshua trees.

After deer had been netted, the helicopter returned to get the baggers. These were two experienced people who removed the net, hobbled and blindfolded the deer, and prepared it for transport.

The deer was transported in a canvas bag and then lowered into the back of the truck. The truck drove a short distance to the processing area.

On this trip, two deer were transported, one in the yellow bag and one in the blue bag. 

The first processing step was to weigh the deer. The ones I saw weighed between 55 and 62 kg. Only does were captured.

Next the team took the bag off the deer. Most of the deer were relatively calm during this process. Once in awhile the deer was more agitated and got hot and had to be cooled off with water.

Here are the two deer, being processed next to each other. The deer's length, girth, and metatarsal (part of the leg) were measured. The teeth were assessed to determine the general age. Pellets were removed for fecal analysis, and a rectal temperature was taken. A hair sample was collected, and heart and respiration rates recorded.

Here is a vet administering lidocaine in the deer's mouth. A tooth was pulled to determine the exact age.

Three shots were given: penicillin, vitamin E, and selenium. Some areas are naturally selenium deficient, and the shot helps keep the deer healthy. The vitamin E helps temper the selenium shot, and the penicillin fights off possible bacterial infection.

The collar has two parts: a VHF transmitter and a GPS transmitter. The deer can then be tracked by satellite and by using an antenna.

The collar is carefully sized so as not to interfere with the deer's movements and to allow for growth in younger animals.

All the does had an ultrasound performed to determine body condition and to detect how many fetuses she was carrying. Most were carrying twins.

Finally it was time to take the doe back. It was loaded on to the canvas carrying mat and taken to the truck.

The blindfolds help keep the deer calmer. This deer is ready to head back home.

And to get home, it goes in style--by helicopter.

This is a quick overview of the whole process. Come back tomorrow for more photos and even a video!