TRENDS IN IOWA WILDLIFE POPULATIONS AND HARVEST 2001 Iowa Department of Natural Resources JEFFERY R. VONK, Director October 2002 TRENDS IN IOWA WILDLIFE POPULATIONS AND HARVEST 2001 Compiled by: Peter Fritzell Chapters Prepared by: Willie Suchy White-tailed Deer Todd Gosselink Wild Turkeys & Ruffed Grouse Ron Andrews Furbearers & Wildlife Restoration Guy Zenner Waterfowl Todd Bogenschutz Upland Wildlife Doug Harr Wildlife Restoration Pat Schlarbaum Wildlife Restoration Bruce Ehresman Wildlife Restoration Mark McInroy Wildlife Restoration CONSERVATION & RECREATION DIVISION October 2002 Iowa Department of Natural Resources JEFFERY R. VONK, Director TABLE OF CONTENTS WHITE-TAILED DEER Historical perspective .....................................................................................................................1 2001 Hunting Season Results .........................................................................................................2 Population surveys ..........................................................................................................................5 Outlook for 2002 .............................................................................................................................5 Tables ..............................................................................................................................................7 Figures ..........................................................................................................................................21 WILD TURKEYS Historical perspective ...................................................................................................................29 Spring harvest survey ....................................................................................................................30 Fall harvest survey ........................................................................................................................31 Brood survey .................................................................................................................................34 Tables ............................................................................................................................................37 Figures ..........................................................................................................................................49 FURBEARERS Historical perspective and current season results ........................................................................53 Tables ............................................................................................................................................58 Figures ..........................................................................................................................................71 WATERFOWL Duck breeding populations ...........................................................................................................74 Giant Canada Goose Populations .................................................................................................74 Waterfowl harvests ........................................................................................................................75 Waterfowl seasons ........................................................................................................................76 Waterfowl banding ........................................................................................................................76 Tables ............................................................................................................................................77 Figures ..........................................................................................................................................90 UPLAND WILDLIFE Historical summary of populations and harvest ...........................................................................93 2001 results ...................................................................................................................................97 Tables ..........................................................................................................................................103 Figures ........................................................................................................................................118 WILDLIFE RESTORATION Peregrine Falcons .......................................................................................................................124 River Otters .................................................................................................................................143 Greater Prairie Chickens ............................................................................................................148 Ruffed Grouse .............................................................................................................................160 Wild Turkeys ...............................................................................................................................168 Canada Geese .............................................................................................................................180 Trumpeter Swan...........................................................................................................................184 Osprey ........................................................................................................................................192 Sandhill Cranes ..........................................................................................................................195 Bald Eagle ..................................................................................................................................198 Bobcats .......................................................................................................................................210 Mountain Lion ............................................................................................................................212 Black Bear ..................................................................................................................................215 WHITE-TAILED DEER Historical Perspective the federal Conservation Reserve Program (CRP). Standing corn also White-tailed deer (Odocoileus provides ideal habitat for part of the year virginianus) were reported to be quite since it provides food, cover and easy abundant when European settlers arrived in travel lanes. Deer utilize almost all plants Iowa in the early 1800's. Although the for food at one time or another during the clearing and cultivating of land for year. Deer feeding habits can best be agriculture may have initially improved the described as being randomly selective as suitability of the landscape for deer, deer will sample many plants while uncontrolled exploitation for food and feeding but often utilize a single source hides rapidly reduced deer numbers. By of food for the majority of their diet. 1880, deer were rarely sighted in much of The whitetail's ability to thrive in the state and, in 1898, the deer season was Iowa is likely the result of an abundant, legally closed. By this time deer had been reliable food source and a winter climate virtually eliminated from all parts of the where snow depths rarely exceed 12" for state. a prolonged length of time. These factors Re-establishment of deer into the combine to allow deer to come through state can be traced to escapes and releases the "winter bottleneck" in excellent from captive herds and translocation and condition. The excellent nutrition also natural immigration from deer herds in enables deer to have high reproductive surrounding states. A conservative rates. Many does in Iowa have a single estimate of the population in 1936 placed fawn their first year and 2 fawns each statewide numbers at between 500 and 700 subsequent year. Deer in the wild can animals. This small herd grew steadily. probably maintain these high By 1950 deer were reported in most reproductive rates until they are well past counties and the statewide estimate topped 10 years of age. Past research in Iowa 10,000. Concentrations in some areas were has found that 8 to 12% of adult does beginning to cause problems by damaging have 3 fawns. agricultural crops. In response to these Another reason that deer do so problems the first modern deer season well in Iowa is that they are very mobile. was held in December of 1953 and 4,000 Although many deer never move far from deer were killed. This spring the deer the area where they were born, a herd was estimated to be about 210,000 significant number (10-20% on average) before the fawning season. The harvest leave and travel to new areas before in 1996 exceeded 100,000 for the first establishing a core area. These core areas time ever. may change seasonally with deer shifting Although deer are frequently between wintering areas and fawning associated with forested areas, deer will areas. These movements allow deer to utilize many different types of habitat as fill voids left open due to deaths and long as the area provides adequate cover. changing habitat. Thus deer easily Examples of these types of areas include pioneer into new areas when habitat is brushy draws and fencelines, marshes, suitable. The highest rates of movement and grassy areas like those provided by occur during 2 periods of the year. The 1 first is in