Colorado Mule Deer B&C

[Jimss]

If you take a closer look at counties producing the whoppers you'll get a feel for the future. Around 2010 to 2015 there were a heck of a lot of B&C bucks coming out of the Gunnison Basin. There was very little winterkill in that area over those years. My prediction is that you can almost remove Gunnison County from B&C entries from 2017 through at least the next 5 years. Prior to the early 2010's there weren't many B&C bucks harvested in the Gunnison Valley due to severe winters. The genetics are fantastic if bucks can live long enough!

The CPW also started offering early high country hunts across Colo in relatively recent years. Those additional rifle tags put additional pressure on an additional chunk of older age bucks. If there are back to back winterkill years along with 5 years of later rifle season dates you can count on B&C entries taking significant drops. It usually takes 6 to 7+ years to produce a B&C buck. That is quite a few hunting seasons and winters to survive! With later rifle season dates hopefully the CPW will be smart enough not to increase tag numbers!

On the "up-side" it's nice that many of Colo's winter ranges are getting moisture rather than drought....which impacts browse and feed that promotes antler growth.....and health of deer. It's obviously important that does are healthy because they are the ones producing fawns!

Another positive note is Eastern Colo. There will always be B&C entries coming from the Eastern Plains. It is mostly private land plus won't be impacted by late rifle season dates.

My prediction is that overall Colo B&C entries will take a dramatic drop in the next 5 years with the late rifle season dates. How severe the drop is depends in part to tag numbers plus winterkill and drought over those years.

 

[street]

Some quick analysis on the second season rifle "5 year structure" for CO. Data from the cpw website.

First, frequency distributions of the past two season structures and the new 2020-2024 season structure. The previous two structures overlap the calendar dates almost exactly centered around ~October 23rd, with the new structure centered around ~October 31st. So essentially an 8 day shift closer to the peak of the rut.



Assuming a very basic "rut (blue) distribution", here are the new seasons stacked on the rut for illustration.



Lastly, the season structure frequency distributions stacked on the rut.


Perhaps this gives a little insight into what effects could come from this new season structure. In no way does this imply hunters will be more successful during their hunts. But there will be more hunters in the field while mature bucks are more vulnerable which increases probability of those bucks not surviving the season. Food for thought...

 

[street]

Dude this is awesome my statistics isn’t the best but is the distribution for the season dates to model amount of hunters in the field during a given season?

Sorry for the lack of clarity. Take the top plot, yellow data for example. The season dates from 2020 to 2024 range from October 24th to November 7th with October 30th, 31st and November 1st being the most frequent (all 5 seasons) dates among those seasons. Furthermore, November 7th falls in the second rifle season ONLY once in the years 2020-2024. Hope that clears it up.

I made the plots mostly for illustration purposes, but I can try to quantify further if desired!?

 

[sndmn11]

Hasn't there been a call for a higher quality hunting experience for a while now?
I think for a lot of hunters pushing the season dates back is a positive move towards providing that because of the same reason(s) brought up as moving away by a lot in this thread.

 

[IrkedCitizen]

Some quick analysis on the second season rifle "5 year structure" for CO. Data from the cpw website.

First, frequency distributions of the past two season structures and the new 2020-2024 season structure. The previous two structures overlap the calendar dates almost exactly centered around ~October 23rd, with the new structure centered around ~October 31st. So essentially an 8 day shift closer to the peak of the rut.

View attachment 162920

Assuming a very basic "rut (blue) distribution", here are the new seasons stacked on the rut for illustration.

View attachment 162921

Lastly, the season structure frequency distributions stacked on the rut.
View attachment 162923

Perhaps this gives a little insight into what effects could come from this new season structure. In no way does this imply hunters will be more successful during their hunts. But there will be more hunters in the field while mature bucks are more vulnerable which increases probability of those bucks not surviving the season. Food for thought...

Can you do this for 3rd season? 3rd and 4th season are going to have more affect than 2nd.

 

[street]

Can you do this for 3rd season? 3rd and 4th season are going to have more affect than 2nd.

Yes I will do it once I get some more time. Hopefully tonight

 

[IrkedCitizen]

Yes I will do it once I get some more time. Hopefully tonight

Thanks. Sounds good.

 

[street]

Can you do this for 3rd season? 3rd and 4th season are going to have more affect than 2nd.

Ok here is what we got.

*was a small mistake in previous 2nd Season, updated here:
2nd Rifle seasons

3rd Rifle seasons


4th Rifle seasons


More to come.

 

[street]

Is the new 2nd Rifle the previous 3rd Rifle seasons? 3rd the new 4th? Here is the data.





Large amount of overlap between the new 3rd season and the previous 4th seasons. Not as much between 2nd and previous 3rd.

 

[street]

Looks like I was under the wrong impression between 2nd and 3rd Rifle tag allocations. Statewide 2019 rifle total tag allocations.

2nd: 27,417
3rd: 25,544
4th: 3,231

If those allocations stay the same between 2020-2024, I can't imagine that going smoothly on the upper age class bucks for the future.

 

[HiMtnHntr]

If only we could all experience deer hunting like those ole boys in the 50s, 60s, and 70s did! My oh my...

 

[IrkedCitizen]

Looks like I was under the wrong impression between 2nd and 3rd Rifle tag allocations. Statewide 2019 rifle total tag allocations.

2nd: 27,417
3rd: 25,544
4th: 3,231

If those allocations stay the same between 2020-2024, I can't imagine that going smoothly on the upper age class bucks for the future.

What I heard is that the main reason for the season change is to kill the big mature deer in an attempt to curb the CWD. So I doubt they are going to issue less licenses.

 

[sndmn11]

What I heard is that the main reason for the season change is to kill the big mature deer in an attempt to curb the CWD. So I doubt they are going to issue less licenses.

Who said that, when did they say it, where were they and where were you when they said it?

 

[wytx]

What I heard is that the main reason for the season change is to kill the big mature deer in an attempt to curb the CWD. So I doubt they are going to issue less licenses.

I would tend to believe this . Wyoming is starting a push to reduce the overall age structure in CWD areas by harvesting more mature bucks and reducing herd sizes.
Seems research shows older age bucks carry it more often than younger bucks, they want to reduce older age class populations to try and reduce prevalence of CWD.
Wouldn't be a stretch for Colorado to be trying the same.

 

[wyo2track]

Who said that, when did they say it, where were they and where were you when they said it?

There was a plan put into place starting last year by CPW prior to the season license allocation. It was a big deal being discussed on the hunting forums last spring. Reason for so many more 3rd and 4th season tags last year in NW CO units. Here's Colorado's CWD response plan. The assault on buck deer started last year. And Wyoming is going to possibly try the same in a region or two. CWD has been around for years and years, now all of a sudden lets kill everything off. This thread is about B&C trends. Since the western half of CO is traditionally known for producing large bucks, I bet the next 5 yrs there will be a substantial drop in quality on units composed of mostly public land. The CWD plan is to kill the oldest deer available and the easiest way to help do that is with later seasons.

 

[wyo2track]

And for those that don't want to open the CPW CWD Response Plan report, here's the red meat from it....


VIII. Management Actions and Recommendations to Control CWD Prevalence

A. Reduce Population or Density

If the 5% prevalence threshold for adult males is met or exceeded in a herd, the CWD management response may be to reduce the population or density of animals in specific areas. If this management action is selected, herd managers will strive to reduce population to the lower end of the population objective range identified in the Herd Management Plan. Since the population objective range has already been approved through a public process, a formal public process will not be conducted when managers implement a CWD management response. Hunter harvest will be the primary tool used to reach the bottom of the range.

The rate at which the herd is reduced will be determined by the herd managers, though managers will strive to reduce the population to the lower end of the HMP population objective range and reduce prevalence to below the 5% threshold for adult males within 10 years. When prevalence exceeds 10%, it is recommended that herds are aggressively reduced during the years between the first and second round of mandatory testing for that herd.

Treatments prescribed to reduce or maintain prevalence should go into effect the year following mandatory testing. That same herd will be retested under mandatory testing within a 5-year window according to the 15-year CWD Monitoring Plan. If changes to prevalence have not occurred then the intensity of the prescription may be increased. If the population has reached the bottom of the objective range set in the HMP and CWD prevalence is still above the 5% threshold, CPW will consider revision of the HMP objectives through a CPW Commission-approved HMP revision. The following list of tactics will be considered as possible treatments for reducing population or density and may be expanded over time:  Increase female and/or either sex hunting licenses.

 Increase harvest in later seasons or high prevalence areas. 24
 Increase opportunities for harvest, such as increasing access, the availability of PLO licenses, hunting on open spaces, and new special hunts for youth, R3 and new hunter programs.
 Increase harvest by creating a Special Hunting Season for Disease Management in Big Game.
 Increase harvest through targeted population reductions not related to hunter harvest. In areas where hunters are not able to access herds, CPW will consider the use of focused herd reduction measures as a last resort.
 Increase harvest through enhanced cooperation with municipalities, local governments, federal lands management agencies, HOAs, private landowners and Tribal leadership; establish CWD management programs to reduce CWD on open spaces and landscapes where hunting is currently not utilized as a tool.
 Increase hunter access of all types through specialized strategies or programs.

B. Reduce Male/Female Ratio

If the 5% prevalence threshold for adult males is met or exceeded in a herd, the CWD management response may be to reduce the ratio of males to females. If this management action is selected, herd managers will strive to reduce male:female ratio to no lower than the lower end of the sex ratio objective range identified in the Herd Management Plan. Since the sex ratio objective range has already been approved through a public process, a formal public process will not be conducted when managers implement a CWD management response. Hunter harvest will be the primary tool used to reach the lower end of the range.

This management action is expected to be commonly used for deer because adult male deer typically have twice the infection rate as adult females. Reducing the segment of the herd with the highest prevalence should effectively reduce prevalence in the short term. Based on an evaluation in 2018 of all Colorado deer herds that have classification data for at least 2 of the last 3 years, 73% (32 out of 44) have observed sex ratios that exceed the top of their respective HMP sex ratio objective range. This statistic does include several HMPs that have not been updated in many years and current management approaches do not match the outdated HMP objectives; these outdated plans are scheduled for revision.

Another consideration with reducing the male:female ratio is that positive CWD detections in harvested males generally increase in later seasons closer to, and during, the rut. This is because mature males have higher prevalence than younger males and mature males make up a larger proportion of the harvest in later seasons. Focusing hunter harvest of adult male deer during the rut and late seasons may increase the efficiency in removing infected animals from the herd. The rate at which the sex ratio is reduced will be determined by the herd managers, though managers should strive to reduce the sex ratio to the lower end of the HMP sex ratio objective range and reduce prevalence to below the 5% threshold for adult males within 10 years. When prevalence exceeds 10%, it is recommended that the sex ratio is aggressively 25 reduced during the years between the first and second round of mandatory testing for that herd.

Treatments prescribed to reduce or maintain prevalence should go into effect the year following mandatory testing. That same herd will be retested under mandatory testing within a 5-year window according to the 15-year Monitoring Plan. If changes to prevalence have not occurred then the intensity of the prescription may be increased. If the sex ratio has reached the bottom of the objective range set in the HMP and CWD prevalence is still above the 5% threshold, CPW will consider revision of the HMP objectives to lower the sex ratio objective range. The following list of tactics will be considered as possible treatments for reducing the sex ratio:

 Increase male hunting licenses.
 Increase male harvest in later seasons or in high prevalence areas.
 Shift male harvest from early seasons to later seasons in high prevalence areas.
 Adjust hunt codes to focus harvest in specific areas.  Eliminate float groups to better control hunter pressure across seasons.
 Increase opportunities for male harvest, such as changing male licenses from List A to List B, increasing the availability of PLO licenses, hunting on open spaces, and creating new special hunts for youth, R3 and new hunter programs.
 Increase male harvest through enhanced cooperation with municipalities, local governments, federal lands management agencies, HOAs, private landowners and Tribal leadership; establish CWD management programs to reduce CWD on open spaces and landscapes where hunting is currently not utilized as a tool.
 Increase male harvest by creating a Special Hunting Season for Disease Management in Big Game.

C. Change Age Structure

Colorado data has shown that at current prevalence rates, the age classes of deer most likely to be infected are 4-6 year old males. Without changing the population or sex ratio, managers could change a herd’s age structure to reduce the number of 4-6 year-old males and increase the number of 1-3 year-old males. The following list of tactics will be considered as possible treatments to change the age structure:

 Shift male harvest from early seasons to later seasons in high prevalence areas.
 Eliminate float groups to better control hunter pressure across seasons.
 Revise the HMP to lower the sex ratio objective to lower the age structure of the herd.
 Increase opportunities for male harvest, such as changing male licenses from List A to List B, increasing the availability of PLO licenses, hunting on open spaces where hunting is not currently utilized as a tool, and creating new special hunts for youth, R3 and new hunter programs. 26
 Increase licenses and establish an antler point restriction. However, antler point restrictions create an additional regulation to enforce, they assume harvest of adult males will increase, and they may create a surge of younger males entering the mature age classes after a few years of implementation. If deer behavior changes and males become more nocturnal, reduction in population or sex ratio may still be necessary.

D. Maximize Ability to Remove Diseased Animals at the Smallest Scales Possible (hot spots)

CWD-positive animals are not uniformly distributed in a herd or over land area. Of great value to managers is an understanding of how CWD-positive animals are distributed at the smallest scale possible. This is because the most effective way to reduce CWD prevalence is to expeditiously remove concentrations of infected animals. CPW currently requires hunters to report the location of harvest and often obtains GPS locations when collecting CWD samples from hunters. Harvest locations are matched with CWD test results to map all of the positive animals harvested and determine where hot spots occur. For herds that include large geographic areas, prevalence estimates may be heavily influenced by high prevalence found in a few hot spots. Targeted management actions would help achieve the CWD management objective of maximizing the impact on CWD while minimizing the impact on herds.

 

[sndmn11]

And for those that don't want to open the CPW CWD Response Plan report, here's the red meat from it....


VIII. Management Actions and Recommendations to Control CWD Prevalence

A. Reduce Population or Density

B. Reduce Male/Female Ratio

D. Maximize Ability to Remove Diseased Animals at the Smallest Scales Possible (hot spots)

I read your highlights.
I read that as saying those are separate possible actions if the testing for CWD proves to be positive in more than 5% of adult males that are tested. I don't read that as plans for all units west of I25 that are under the CWD ceiling. I think this is a bit like the story of Chicken Little.

 

[wyo2track]

I read your highlights.
I read that as saying those are separate possible actions if the testing for CWD proves to be positive in more than 5% of adult males that are tested. I don't read that as plans for all units west of I25 that are under the CWD ceiling. I think this is a bit like the story of Chicken Little.

The map below is directly from CPW's website this morning..

 

[sndmn11]

The map below is directly from CPW's website this morning..

What I heard is that the main reason for the season change is to kill the big mature deer in an attempt to curb the CWD. So I doubt they are going to issue less licenses.

Thank you, the map supports my point. A minority of the state exceeds the 5%, so that cannot be the main reason for the season change in all units west of I25. If the argument were true and that it were the MAIN reason, then it would only have been applied to the units exceeding the 5%, and there wouldn't have been a change to other species (elk).

 

[IrkedCitizen]

In addition to what @wyo2track posted.
Top of page 21 in the Colorado big game regulations. 89 GMU's have MANDATORY testing for all deer killed in rifle seasons. EIGHTY-NINE UNITS. Their focus is on CWD. Period.