N.D. wildlife faces challenge to reproduce
North Dakota’s wildlife may have survived the winter, but the real challenge to its numbers will come this spring as those animals try to reproduce.
Randy Kreil, chief of the North Dakota Game and Fish Department’s Wildlife Division, said he didn’t believe there was a lot of adult mortality in the deer and antelope populations.
“One of the biggest impacts of a bad winter is not the loss of adults during the winter but the lack of reproduction next spring,” he said. “In order to survive, they’ll actually reabsorb the fetuses for the energy and they just won’t have fawns the next spring.”
Kreil said deer numbers are down because deer population hit a record high in 2007, causing many car-deer collisions and problems for farmers and ranchers. That year the state issued 150,000 hunting licenses, and that aggressive harvest coupled with three bad winters in 2008-10 cut those numbers down dramatically. Kreil said a lack of grasslands, especially in the Stutsman County area, is exacerbating that population decline.
The Game and Fish Department performs aerial winter population surveys every year for white-tail deer when there is enough snow cover to blanket the landscape so the deer can be seen from a plane. With a lack of snow this fall, the only survey for white-tail deer was performed in the northeast corner of the state. Kreil said the numbers were not encouraging.
“We had about a 20 percent decline in the numbers in the very northeast corner of the state in our winter deer surveys,” he said. “We don’t know, but we suspect a similar trend has occurred through the rest of the state based on a couple other factors.”
Kreil said the number of successful deer hunters in North Dakota last season was about 55 percent of the 59,500 licenses issued, which is down from 63 percent of the 65,000 licenses in 2012. The department has a standing target of a 70 percent success rate. Kreil expects fewer licenses to be issued this year, and the department will release that number within the next two weeks.
Kreil said the loss of grasslands hurts deer — which are born and raised in that habitat — and upland game birds like pheasants and grouse. The biggest challenge for the birds, he said, will be finding suitable nesting areas this spring.
“Without those grasslands to nest in, even though they made it through the winter they’re not going to be successful in raising broods this year and the population will decline,” he said. “People need to be very concerned about the loss of habitat that’s ongoing in this state, and if people want to maintain the hunting opportunities that we’re used to, it’s going to take a concerted effort on the part of everybody from political leaders in Congress all the way down to the state, to the local wildlife clubs, local hunters and local agricultural producers to try to maintain habitat.”
Fish are flourishing
Officials in the Game and Fish Department’s Fisheries Division said the lack of snowfall on state lakes this winter dramatically helped reduce the amount of winterkill, and fish populations in the state are currently at an all-time high.
The department has asked anglers to report any lakes with winterkill to their local game and fish offices.
“The ice is going off in most of the state right now, and I’m not sure if we had any new lakes that were pointed out to us, so I think we’re in pretty good shape,” said Greg Power, Fisheries Division chief.
Jerry Weigel, Fisheries Production and Development Section leader, said winterkill occurs when oxygen levels in a lake drop so low the fish suffocate. High water levels before freeze-up will hold more oxygen going into the winter, but plants in the lakes need sunlight to continue to produce oxygen. If the lake is covered with a thick snowpack and sunlight cannot reach the plants, then they will die. If there are a lot of plants, the decomposition progress will consume more oxygen.
“We manage some lakes that we know are real, real, shallow,” Weigel said. “Some urban ponds — an example in Jamestown would be that little kids’ pond by Jamestown Reservoir — I can guarantee that dies every year.
“Something shallow like that is not going to make the winter, and we know that and we expect that. It’s when all of sudden like Spiritwood Lake has almost no winterkill. If a lake like that were to winterkill, it would be a big deal.”
Power said an average of six to 10 lakes —sometimes more than a dozen — out of the approximately 420 lakes the department manages have winterkill each year.
Game fish like northern pike, walleye and perch are more susceptible to low oxygen levels than bullheads and carp. Trout especially need a high level of dissolved oxygen in their water, but the state doesn’t manage many trout-filled lakes.
“Sometimes we have a winterkill and we have rough fish in that lake,” Power said. “We’d just as soon have a complete kill versus a partial kill, because if we have a partial kill that means the bullheads survived and everything else didn’t.”