FILING - 06/30/2008
Basis and Purpose
Chapter 2 - Big Game
Basis and Purpose:

These regulations amend Chapter 2 – Big Game – of the Wildlife Commission regulations and are necessary to properly manage big game populations in Colorado.
 
These regulations establish limited license numbers for deer, elk, pronghorn, moose, and black bear during seasons which were adopted in January 2008; and include licenses for archery, muzzle-loading, early, regular, plains, late rifle and private land only seasons with respect to each species.  Limited license numbers are set for specific game management units or groups of units, although some limited licenses, particularly muzzle-loading elk licenses, are valid over much of the state.  Limited license numbers are established to maintain big game herds at or near long-term population objectives, and, in the case of antlered deer, antlered elk, buck pronghorn and moose they are also set to achieve sex ratio objectives.  The herd objectives are intended to maintain healthy populations, provide a diversity of hunting opportunities for residents and nonresidents, allow and maintain public recreational opportunity, minimize or control local game damage situations on private land and provide opportunity for landowners to cooperatively manage wildlife with the Division through the Ranching for Wildlife program.  These resulting limited license numbers take into account harvest estimates and hunter success rates, wildlife counts and surveys, as well as impacts of winter weather and predation on big game populations.  As is the case each year, this effort represents the culmination of numerous hours of work by various Division employees involved in the accumulation and analysis of data and a great deal of time spent with interested publics explaining both the recommendations and the rationale behind them.

Population Modeling

The Division adopted new modeling methodology to estimate 2007 posthunt populations in most Data Analysis Units.  This new methodology produces a series of models for each DAU that are based on a variety of assumptions and numbers of parameter estimates.  Population estimates are derived using a mathematical optimization procedure that provides the best possible fit to multiple sources of observed data (i.e., sex ratios, survival rates, harvest, quadrat estimates, distance sampling estimates, minimum counts).  The new methods provide a more objective approach to population modeling and allow simple models with few assumptions and parameter estimates to be evaluated against more complex models.  Model selection is based on a combination of goodness of fit to observed data, parsimony of parameter estimates, and biological reasonableness.  The new modeling procedure was not used in a small proportion of DAUs because of insufficient or problematic data.  In some cases the new models produced substantially different population estimates than previous models.

Black Bear

Black bear hunting seasons and license number allocations are governed by Data Analysis Unit plans, which describe the geographic area and a historical perspective of harvest, non-harvest mortality, human conflicts and game damage.  Bear DAU plans were approved by the Wildlife Commission in 2000.  The DAU plans contain general objectives for harvest and total mortality.  These objectives are monitored on a 3-year running average basis.  Managers examine mortality averages and types with consideration of changing environmental conditions, results of applicable research, and local knowledge and experience related to forage conditions, access, and changes in land status relative to black bears.  Considering the foregoing information, then harvest objectives are identified and licenses allocated to achieve or remain within the harvest objective, but also to provide diverse recreational opportunity among a variety of season types and dates, and in some DAUs to allow for harvest to help reduce or mitigate human-bear conflicts and damage to agricultural products by black bears.  Non-harvest mortality is also examined with consideration of similar factors but with recognition that these mortalities are often beyond the scope of manager’s control and are often variable.  Therefore, short term increases or declines in observed DAU non-harvest mortality are not significantly influential in annual license allocation determination.  However, consistent trends may result in increases or decreases in harvest objectives and consequent license allocations.

In 2008 the sum of DAU harvest and total mortality objectives is 643 and 834 respectively.  The sum of license allocations for all DAUs is 10,675 licenses, a 2.7% (285 licenses) increase from the 2007 allocation.  The predicted harvest with the approved license allocations is 546 and females are expected to comprise about 36% to 38% of the harvest.  Considering the above described management factors, DAU B-3 license allocation is reduced from 2007 allocation by 13% (65 licenses), due to exceeding the harvest objective, female component of harvest, and increasing amounts of non-harvest mortality.  In DAUs B-4, B-6, B-7, B-9, B-13, and B-16 bear populations appear gradually increasing and licenses are slightly increased by 6.5 % (145 licenses).  In these DAUs hunter harvest is below objective and the female component of harvest is acceptable.  Most of the license increases are Private Land Only (PLO) Licenses.  PLO licenses afford the opportunity to take some bears that may pose conflicts as hunter harvest, instead of control action kills.  Portions of DAUs B-5, B-10, B-11, and B-17 experienced significant natural forage failures in 2007 resulting in higher than normal non-harvest mortality.  But on average these DAUs remain at or below harvest objectives.  In these DAUs some licenses have been allocated as Private Land Only (PLO) while other license allocations remain the same as in 2007.  Total license allocation in these DAUs is increased 5% (205 licenses).  Leaving other license allocations the same as past years will allow easier examination for changes in hunter success rates as an indicator to changes in bear populations and vulnerability.  All other DAU license allocations remain the same as in 2007.

Deer

Since 1999, all deer licenses in Colorado have been limited and specified by game management unit or groups of units.  Deer numbers in Colorado have increased since license limitation primarily due to increases in the number of bucks.  The 2007 deer harvest was the highest since 1997 with 98,283 hunters harvesting 45,026 deer for a 46% success rate.  The 2007 deer harvest consisted of 12,772 antlerless deer and 32,254 bucks.  The 2007 buck harvest was similar to buck harvest during the previous 3 years but antlerless harvest in 2007 was 44% higher than the average antlerless harvest between 2000-2006.  Rifle hunters, archery hunters, and muzzleloader hunters accounted for 89% and 90%, 6% and 5%, and 5% and 5% of the buck and doe harvests, respectively.

In 2008 the Division adopted new modeling methodology that substantially reduced deer population estimates in some DAUs.  The estimated statewide deer population in 2007 was 539,000 deer compared to the 2006 estimate of 611,000.  The difference in these estimates is mostly attributable to changes in the models rather than an actual decrease in the statewide deer population.  The largest changes in population estimates occurred in some DAUs in the NW region (e.g., D-7, D-8, D-13, D-14) and SW region (e.g., D-19, D-24, D-40).  The current posthunt, population objective range for deer DAUs statewide is between 581,000 and 618,000 and is based on previous models. The average, observed posthunt ratio of bucks/100 does weighted by population size in 2006 was 32 with an average, objective range for DAUs statewide between 27-29.  Most deer DAUs are near or over buck/doe ratio objectives.

All deer licenses remain limited in 2008.  As a result of changes in some DAU population estimates, the relatively high antlerless harvest in 2007, and low demand for antlerless licenses in some DAUs, the number of antlerless rifle licenses recommended for 2008 in deer DAUs west of I-25 was reduced 47% from 30,989 in 2007 to 16,315.  The number of either-sex rifle deer licenses was reduced 35% from 5,324 in 2007 to 3,456.  The largest reductions in antlerless and either-sex licenses were in D-7, D-2, and D-8. The new models had less effect on population estimates in the plains units and there is continued effort to control white-tailed deer numbers in some of these DAUs.  Hence, antlerless rifle licenses east of I-25 were increased 7% from 3,545 in 2007 to 3,786.  The number of either-sex rifle licenses east of I-25 was also increased from 122 in 2007 to 563. The number of antlered rifle deer licenses for 2008 west of I-25 was decreased 23% from 62,883 in 2007 to 48,657 primarily as a result of the lower population estimates.  The largest reductions in buck licenses were also in D-7, D-2, and D-8.  The number of antlered rifle deer licenses for 2008 east of I-25 was decreased 5% from 3,420 in 2007 to 3,238.  The predicted 2008 deer harvest is 41,300 with a predicted 2008 posthunt population estimate of 532,000. 

The winter of 2007-2008 brought unusually deep snow and cold temperatures to some deer winter ranges on the west slope.  Conditions in the Gunnison Basin (D-21, D-22, D-25) were particularly hard resulting in the Division mounting a large-scale feeding operation that started in mid-January and continued through mid-April.  Approximately 9,500 deer, almost half of the estimated Gunnison Basin deer population, were being fed a complete pelleted diet at the height of the operation.  Smaller scale deer feeding efforts occurred around Eagle (D-8, D-14).  The extent of winter mortality in these areas is yet to be determined but it is likely that winter fawn survival and possibly adult buck survival were much lower than average.   In other areas on the west slope, winter fawn survival appeared to be lower than any year since regular fawn survival monitoring began in 1997 but probably did not go much below 40% based on the survival of radio-collared fawns in the monitoring areas (D-7, D-9, D-19).  Doe survival remained at or above average in the monitoring areas.  As a result of the winter conditions in Gunnison, the number of antlered rifle deer licenses in D-21, D-22, and D-25 was decreased by 44% (from 1,735 in 2007 to 970) and the number of antlerless rifle deer licenses was decreased by 59% (from 1,155 in 2007 to 470).

Elk

In 2007, 227,262 hunters harvested 49,012 elk in Colorado for a 22 percent success rate.  This was the first year since 1999 that statewide elk harvest dropped below 50,000 with hunters taking 8,000 fewer elk than in 2006.  The decrease in elk harvest in 2007 was likely due to a combination of factors including unusually mild weather during the 3rd and 4th rifle seasons, 5,000 fewer limited elk licenses, 10,000 fewer elk hunters, and a decrease in the estimated number of  elk. 

The 2007 bull harvest (24,137) was down approximately 2,700 from 2006 but only 4% below the average annual bull harvest between 2000-2006.  Antlerless elk harvest in 2007 (24,875) was down by over 5,000 from 2006 and down 21% from the 2000-2006 average. Rifle hunters, archery hunters, and muzzleloader hunters accounted for 78% and 90%, 15% and 6%, and 7%, and 4% of the bull and antlerless harvests, respectively.

In 2008, the Division adopted new modeling methodology that resulted in increased elk population estimates in some DAUs in 2007.  The estimated statewide elk population in 2007 was 292,000 elk compared to the 2006 estimate of 272,000.  The largest increases in elk population estimates occurred in E-6, E-14, E-31, E-16, E-15, and E-8.  The difference in these estimates is mostly attributable to changes in the models rather than an actual increase in the elk population.  The new models and harvest data indicate elk populations have actually been reduced over the past few years as a result of aggressive cow harvest.  The current posthunt population objective range for elk DAUs statewide is between 202,370 and 234,920 and is based on previous models. The average, observed posthunt ratio of bulls/100 cows weighted by population size in 2006 was 28 with an objective range for DAUs statewide between 23-26.  Most elk DAUs are near or over bull/cow ratio objectives.

The majority of rifle bull licenses and archery either-sex or antlerless licenses remain unlimited in 2008.  The number of limited antlerless and either-sex elk licenses decreased 11% from 136,042 in 2007 to 121, 008 in 2008. The largest decreases were in E-6, E-2, E-24, E-16, E-12, and E-4.  Although population estimates increased in some of these DAUs as result of the new models, antlerless licenses were decreased because current models showed rapid decline in these populations if high antlerless harvest rates were continued.  The number of 1st season, limited rifle bull and either sex licenses, excluding PLO licenses, remained almost constant at 21,015 in 2008 versus 21,018 in 2007 whereas the number of 1st season, rifle either-sex PLO licenses decreased 11% from 6,015 in 2007 to 5,330 in 2008.  The number of 4th season limited, rifle antlered and either-sex licenses decreased 16% from 11,376 in 2007 to 9,566 in 2008.  The largest decreases in 4th season bull and either-sex licenses were in E-6, E-2, and E-16.  The predicted 2008 elk harvest is 51,800 with a predicted 2008 posthunt population of 274,000.

Unusually deep snow and cold temperatures during the winter of 2007-2008 resulted in elk feeding operations in the Gunnison Basin and around Creede, Maybell, Eagle, and Steamboat Springs.  The primary purpose of these operations was to reduce conflicts between elk and agricultural interests and to reduce elk-vehicle accidents.  In some cases such as in the Rio Grande, they were also done to assist elk stranded in deep snow.  Overall, winter elk mortality did not appear to be unusually high but increased mortality, especially of calves, likely occurred on a localized basis.  

Pronghorn

In 2007, 12,647 hunters harvested 8,492 pronghorn for a 67% success rate. The 2007 pronghorn harvest was the highest since 1997 and consisted of 3,637 does and 4,855 bucks. Rifle hunters, archery hunters, and muzzleloader hunters accounted for 89% and 98%, 9% and 1%, and 2%, and 1% of the buck and doe harvests, respectively. The 2007 doe and buck harvests were 33% and 34% higher than the 2000-2006 average annual doe and buck harvests, respectively. Harsh winter conditions on the eastern plains in 2006-2007, particularly in the southeastern corner of the state where the Division undertook a feeding operation, did not appear to have a major impact on pronghorn populations.

New modeling methodology adopted by the Division in 2008 did not substantially change pronghorn population estimates in most DAUs.  The estimated statewide posthunt pronghorn population was 72,600 in 2007 compared to 72,500 in 2006.  The current population objective range for pronghorn DAUs statewide is between 63,180 and 65,930. The average, observed prehunt ratio of bucks/100 does weighted by population size in 2006 was 49 with an objective range for DAUs statewide between 40-41.  Most pronghorn DAUs are near or over buck/doe ratio objectives.

All pronghorn licenses remain limited in 2008 with the exception of archery licenses in some DAUs.  The number of doe rifle licenses recommended for 2008 was increased 10% from 2006 (6,767 to 7,447) whereas the number of buck rifle licenses was increased 4% from 2006 (5,969 to 6,210).  The largest increases in doe license numbers were in A-7, A-13, and A-6 and the largest increase in buck license numbers was in A-7.  License numbers were increased to help move populations towards DAU objectives.  The predicted 2008 pronghorn harvest is 10,000 with a predicted 2008 posthunt population of 70,800.

The winter of 2007-2008 is not expected to have an unusual impact on pronghorn populations with the exception of the Gunnison Basin where as many as 690 pronghorn were being fed a complete pelleted diet because of unusually deep snow and cold temperatures.  Although the extent of winter mortality in pronghorns in the Gunnison Basin is yet to be determined, indications are that mortality was considerably higher than normal.  As a result, the number of rifle buck licenses in A-23 was reduced from 13 in 2007 to 7 in 2008 and there are no doe licenses.

Moose

Moose populations appear to be doing well in the northern part of the state but are stable at best   in M-4.  In 2007, 178 moose hunters harvested 66 bulls and 77 antlerless moose for a total success rate of 80%.  In comparison, 177 moose hunters harvested 72 bulls and 63 antlerless moose in 2006.  In the future, the Grand Mesa moose population will offer additional hunting opportunity in Colorado.

The estimated statewide posthunt moose population in DAUs open to moose hunting was 1,270 in 2007 compared to 1,420 in 2006.  This ostensible population decrease was due to an error that resulted in an overestimate of the M-1 population in 2006.  The corrected 2006 population estimate is similar to that of 2007. The current population objective range for moose DAUs currently open to hunting is between 1,290 and 1,590.  

All moose licenses remain limited in 2008 and demand will far exceed the supply.  The number of bull licenses for 2008 remained the same as 2007 at 74.  The number of cow licenses increased slightly from 105 in 2007 to 108 in 2008.

The statutory authority for these regulations can be found in § 24-4-103, C.R.S., and the state Wildlife Act, §§ 33-1-101 to 33-6-209, C.R.S., specifically including, but not limited to: §§ 33-1-101, 102, 104, 105, 106-108, 115, and 121; §§ 33-2-104, 105, 106, and 107; § 33-3-104; §§ 33-4-101, 102, 102.5, 103, 116, 116.5, 117, and 119; § 33-5.5-102; and §§ 33-6-107, 109, 112, 113, 113.5, 114, 114.5, 117, 119, 120, 121, 124, 127, 128, 129, 131, 205, 206, 207, and 208. 

EFFECTIVE DATE - THESE REGULATIONS SHALL BECOME EFFECTIVE JULY 31, 2008 AND SHALL REMAIN IN FULL FORCE AND EFFECT UNTIL REPEALED, AMENDED OR SUPERSEDED.

APPROVED AND ADOPTED BY THE WILDLIFE COMMISSION OF THE STATE OF COLORADO THIS 13th DAY OF JUNE, 2008.
APPROVED:
Robert W. Bray
	Chairman
ATTEST:
Timothy R. Glenn
Secretary