It never gets old – the enthusiasm of a rocket net shoot. This time we are trying to catch wood ducks (Aix sponsa) as part of a postbreeding ecology study in the Illinois River Valley. We picked the site at Rice Lake State Fish and Wildlife Area two weeks prior with permission from Illinois Department of Natural Resources (IDNR). Hauling buckets of corn every day or every other day to attract the birds and concentrate them for capture is labor intensive. Everyone contributes to the process; otherwise known as “Team Forbes.”
Finally, the birds have developed a pattern, the net is placed, rockets positioned, tent staked and detonating wire strung. Who wants to go on the shoot tomorrow morning, knowing the wake-up time is 3 a.m.? Without hesitation a four-person crew is assembled and meets at the rendezvous location at 4 a.m. Quiet chit chat in anticipation of the morning fill the truck on the 30-minute ride to the middle of nowhere along Copperas Creek Road into the Illinois River floodplain. The four of us jump on the ATV and head down the levee into the middle of Big Lake. The charges “dynamite” are placed in the rockets and continuity is checked with a blasting galvanometer. 18 ohms, reports from the tent. OK, we’re good to go. Eighteen ohms in this situation means the charges are wired successfully, and the net is ready to fire.
All set, it is 5:15 a.m., and sunrise isn’t arriving until shortly after “6 bells.” About 5:30 a.m. wood ducks start darting about seeking the pile of corn on the shoreline of the levee. They keep coming, first 5, then 10, before we know it there are 150 or so within 50 feet of the net. Then our hearts drop, two hungry raccoons come striding across the shallow water and occupy the pile of corn. “Son-of-a-Gun” and a few other expletives are expressed in the tent. At first the ducks flush, but soon they calm down and watch as those hungry critters menace the bait pile. The wood ducks quickly become accustomed to the unwelcome visitors and slowly close in on the bait pile.
Finally, about 5:50 a.m. the raccoons have had their fill and mosey off to the side of the bait. The flock of wood ducks concentrate on the pile of corn at the center of the rocket net. Looking at the bait pile with optics, someone says “I think we have about 60 birds in the capture zone.”
Then shortly, “BOOM,” the rockets fire and the net deploys to maximum reach, 60-feet by 40-feet. Nearly 200 wood ducks take flight, and 53 are snagged out of the air as the net falls to the water. “Got’em” within the tent as the crew scrambles to the net. One by one the ducks are removed and crated up for transport to the Forbes Biological Station so the birds can be fitted with VHF and cellular transmitters.
In subsequent days, Team Forbes will track the marked birds and monitor their status. Cellular marked birds are monitored via computer through the GSM cellular network, and VHF birds are tracked twice daily from trucks equipped with Yagi antennas. This study will provide IDNR with information to manage wetland habitats and harvest of this important species within the waterfowl hunting community. Typically, wood ducks are the second highest bird in the annual harvest of ducks in Illinois, and the most abundant nesting duck in Illinois.
Aaron P. Yetter is a Waterfowl Ecologist at the Forbes Biological Station, Illinois Natural History Survey.