ILLINOI S UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN PRODUCTION NOTE University of Illinois at Urbana-Champaign Library Large-scale Digitization Project, 2007. •A 3J 98 ILLINOIS k T A P T'I TY' A Tw wr rx-%e -% 7r HISTORY ATURAL SURVEY .Cltion of Wildlife Research Performance Report Final Completion Report Illinois Forest Game Investigations W-87-R-8,9,10 1 July 1986 through 30 June 1989 by Charles M. Nixon 31 August 1989 I I _~ · I _ · ~ / : ° Performance Report Final Completion Report State: Illinois Project No.: W-87-R-8,9,10 Project Type: Research Sub-project VII: Illinois Deer Investigations Period Covered: 1 July 1986 through 30 June 1989 This performance report covers the jobs active under the R-10 segment and represents a completion report for Study VII-D-2 (Life History and Ecology of Farmland Deer) and Study VII-D-3 (Strategies For Developing and Managing Systems of Secure Wintering Sites For Deer in Central and Northern Illinois) and a report of progress for Study VII-D-1 (Population Dynamics of the Illinois Deer Herd--Current Status, Harvest Analysis, and Formulation of Alternative Management Strategies), a continuing study within the newly approved W-87-R-11,12,13 project. Report of Progress Study No. VII-D-1; Title: Population dynamics of the Illinois deer herd--current status, harvest analysis, and formulation of alternate management strategies. Objectives: To develop specific deer population goals for counties and regions, to continue to analyze the annual status and harvest of deer, to evaluate requests for hunting permits, and to develop alternative harvesting regulations that balance hunter satisfaction with deer population dynamics. 2 (a) Activity: Deer Populations and Harvests Deer harvests and hunter success rates for 1988 were entered into a new main frame computer at the University of Illinois (The Cyper Mainframe computer system was discontinued 31 December 1988). Updated estimates of the 1988 harvest and programs to provide harvest breakdowns by county, region, and statewide were provided to the Illinois Department of Conservation. In 1988, 114,470 firearm hunters reported killing 47, 505 deer, a 10.6% Increase in reported kill from 1987 and a new record harvest for Illinois (Table 1). Hunting pressures increased about 14.5% in 1988 and with harvest levels up about the same amount, firearm hunter success remained above 40% (Table 1). However, hunter success declined In many counties in 1988. Harvests and hunter success were the same or higher in Deer Region 1 in 1988 for all counties except in Stephenson County where hunter success was down 11.3% from 1987 (Table 2). In Region 2, hunter success was down In 9 counties, evidenced no change in 1 county, and increased in 4 counties. Harvest totals declined in only 3 counties, Ford, Kendall, and Livingston, In 1988 In this Region (Table 2). Harvest totals declined In Putnam and Woodford counties in Deer Region 3, and every county in this Region showed a decline or no change In hunter success. In Region 4, only Fulton County killed fewer deer in 1988 than 1987, but 3 hunter success decl Ined In 8 counties and remained about the same as 1987 In 6 counties. Harvests were up In all but Menard County in Region 5, with no Improvement in hunter success In any county In the Region. Harvests declined In Douglas and Edgar counties In Region 6, hunter success Improved in Jasper and Richland counties, and the remaining counties reported declines In hunter success but Increases In harvests. Harvests were up > 40% In Coles, Crawford, Lawrence, and Richland counties In this Region. In Region 7, only Clay county reported an increase in hunter success while 2 counties, Monroe and Wayne, reported a decline in harvest. In Region 8, harvests were reduced in Alexander, Hardin, Pope, and Saline counties and hunter success was reduced or no change (Pulaski County) throughout the Region (Table 2). The reported archery harvest also Increased in 1988, to 7,862 deer. In past years the reported archery harvest has represented about 65% of the actual kill by archers (Kube, unpublished data). The addition of the unreported kill would Increase the total kill by archers to 12,095 deer. The addition of crippling losses to both the reported archery (estimated as 40% of the reported kill) and firearm (estimated as 30% and includes deer killed but not reported) harvests provides a total harvest of 78,690 deer for 1988, a 12.4% increase over the estimated harvest for 1987. Estimates of prehunt deer populations were made for 27 counties scattered throughout the state In an attempt to determine the current status of deer. The methods used to calculate these estimates were as follows: 1) Assume as a starting point that the harvest for 1980, the beginning year, was 20% of the prehunt population. This percentage Is later adjusted on the basis of known harvests (total harvest including firearm and archery crippling rates) In 1986-1988. 2) The reported firearm harvest is adjusted to an annual kill statistic standardized for numbers of hunters for 1980-1988 as: the number of hunters In year X (1981 through 1988) - the number of hunters In year 1 (In this case 1980) X the hunter success rates for year X. This kill by the new hunters in year X Is then subtracted from the reported kill in year X to produce the harvest of a "stable" number of hunters. 3) The standard harvest for year X is then compared with the harvest In 1980 and the percent changes in harvest levels among years are calculated. This Is a measure of the average change in the county deer population among years and reduces the effect of Increasing hunting pressure caused by more hunters In each county. The average percentage change In harvest was then calculated for the years 1986-1988. 4) The reported harvest plus crippling loss (assumed as 30% for firearm hunters and 40% for archers) was then calculated for 1986-1988. This total harvest was then divided by various percentages selected to produce a prehunt population that, when compared with the estimated prehunt population In 1980 (calculated from an estimated 20% harvest in 1980), approximates the rate of change in standard harvest from 1980. 5) These estimates were then adjusted by observing the estimated percentage of the prehunt population harvested and the 1986-1988 trend in standard harvest (up or down). I have assumed that harvest levels in excess of 40% of the prehunt population reduce subsequent deer numbers. If the estimated percentage harvested In 1986-1988 was not plausible (< 30% or > 60%), the initial estimated percentage harvested in 1980 (originally estimated at 20%) was adjusted up or down until the percentage harvested In 1986-1988 appeared reasonable. The estimated prehunt population for 1986-1988 was calculated for 27 counties and is shown In Table 3. In nearly all of these counties, the percentage of the estimated prehunt population being harvested has increased considerably since 1986. However, Increasing harvest levels within these counties has not affected the sexes equally. As shown in Table 1 for the statewide harvest and confirmed In county harvests, firearm harvests kill considerably more males than females in each county (Table 4). The male levels estimated In Table 4 are, in some counties, likely too high, but the relationship between male and female harvests is a consistent one throughout the state and is supported by the actual harvest reports. These data Indicate that the female segment of the population Is still relatively underharvested, with < 35% of prehunt numbers removed by harvest In 1988. Female take was highest in Regions 1, 4, and 7 and lower in Regions 2, 5, and 8 (Table 4). The low harvest rate for Regions 2 and 5 may be a reflection of the abundance of refuges from hunting present In these sparcely forested Regions. These refuges protect a much higher proportion of females than they do males, because of the disparity In home range size between the sexes during the hunting season (see Appendix 1). The hunters In Regions 2 and 5 seem to have more "trophy" hunters than the average for Illinois and often pass up opportunities to kill a doe or fawn In the hope of killing an antlered deer. Permit Requests Requests for "any deer" permits exceeded allocations in 48 counties (49% of the 98 open counties) in 1988 (Table 5). For 31 of these counties where > 80% of the "first choice" requests were met, the excess number of requests can be accommodated using additional "antlered only" or "any deer" permits without much change in deer numbers or hunting pressures. For 17 counties, however, accomodatling all requests for permits would cause a considerable increase in hunting pressure. Most of these counties contain large urban populations and limited hunting opportunities (Table 5). All requests for deer permits cannot be accommodated in these counties under present hunting regulations, and these counties appear to offer an opportunity to use a split hunting opportunity regulation on an experimental basis. For this option, hunters would be offered the choice of hunting during the first or second 3-day season but not both. Use of this option with a mix of "antlered only" and "any deer" permits would allow al I hunter requests to be filled and regulate harvest within desirable limits. There were also excess permits available In 32 counties in 1988 which out-of-county hunters could have obtained if they could also have located an area open to hunting In these counties (Table 6). Use of the relationship between county hunting pressure and deer harvest can be used to project future harvests under various hunting pressures.