Chronic Wasting Disease CWD and Population Declines of Cervid
Chronic Wasting Disease CWD and Population Declines of Cervid
CWD and Population Declines of Cervid
White-tailed deer population declines in a high-prevalence chronic wasting disease region of Arkansas, USA
Heather E. Gaya , Marcelo H. Jorge, Lisa A. Jorge, Mark G. Ruder, Gino J. D’Angelo, Richard B. Chandler, Michael J. Chamberlain
Published: January 7, 2026
https://doi.org/10.1371/journal.pone.0340070
Abstract
Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting cervids worldwide. CWD was first detected in Arkansas in 2015 and as of August 2025 has been detected in 24 counties across the state. Within the Tier 1 CWD management zone of northern Arkansas, average apparent CWD prevalence exceeded 25% at the onset of our study in 2021. We tested the hypothesis that high prevalence of CWD negatively affects white-tailed deer population viability. We collected data from 243 camera traps and deployed GPS-collars on 131 adult deer to monitor population dynamics. Using spatial mark-resight models, we estimated density of adult deer from 2021 to 2024 at three sites across a presumed CWD gradient to assess the impacts of high CWD prevalence on deer abundance. Deer densities declined at all three study sites, at an average 17% (95% CI: 8% − 24%) decline per year. Male densities declined by an average 23% (95% CI: 5% − 31%) per year compared to 15% (95% CI: 2% − 23%) yearly declines for females. These findings suggest that CWD can negatively impact deer populations through direct reductions in density, but additional research is needed to determine if additional factors contributed to these declines. Furthermore, our findings suggest the populations we studied are not sustainable under current harvest regulations.
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Conclusion
Our findings add to a growing body of evidence that CWD can greatly alter deer populations. Given that previous research has demonstrated reductions in survival due to CWD [5], the high prevalence in our study area likely contributed to the observed population declines. However, it is possible that factors other than CWD contributed to the observed trends in deer densities. Future work in this region should document the direct effects of CWD on vital rates such as survival and fecundity to confirm the role of CWD in population declines. At present, few management tools are available to control CWD once established on the landscape. We therefore suggest that wildlife managers focus on slowing or preventing the spread of CWD to uninfected populations, taking actions that aim to stabilize or lower CWD prevalence, and collect accurate data on deer abundance to monitor when harvest limits become unsustainable.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0340070
Arkansas CWD Deer Study Final 2025
4. Objective 4 and 6 - Infection rates and population modeling
a. In 2024, CWD sample prevalence was 40% across the study area, with higher rates seen in males (65%) than in females (34%).
b. Approximately 50% of males tested positive for CWD by the age of 2.5.
c. White-tailed deer abundance in the study area declined, driven by reduced lifespans and lower lifetime reproduction.
d. If survival does not increase, this population is expected to continue to decline.
https://drive.google.com/file/d/1jN5mtvXvz7IYFDQjv4Rasrw60dGe4KMJ/view
Louisiana House of Representative Aug 27, 9:30 AM, HCR-6 CWD
Louisiana House of Representative
Chronic Wasting Disease CWD
Arkansas
Snip…
40:35 “…and conversely, I was co-Principle Investigator in NW Arkansas, where prevalence is approaching 50 percent.”
Snip…
41:00 “Specific to the work in Arkansas, in 2020, the state agency was showing the Prevalence at 30 percent in the Northwest part of the State, so flip a coin, so, 1 out of every 3 deer had the disease. We started that research in 2020, and now, the prevalence rate is now exceeding 40% in both sexes, and 50% in males.”
43:00 “what we’re seeing Arkansas now is, that population is declining about 11% a year.”
snip…
(A letter written from a Mississippi farmer who’s farm has been in his family for more than 100 years, and submitted it in this video presentation, 28 minute mark, another wake up call for sure, of what some have been warning for years, about CWD, but sadly will go by the wayside by the conspiracy theorists spreading fake news…terry)
Alston Ross
Marshall County, Mississippi
My family owns a 2,000 acre farm in Marshall County, which is in North Mississippi. CWD has plagued my farm since 2018 and has become progressively worse over time. We no longer have mature deer over the age of 3 years old on our property. Every buck harvested on our land has tested positive this year. The owners of our neighboring properties have continued to feed deer and ignore MDWFP regulations, which has exacerbated the spread of the disease throughout our area. This farm has been in my family for over 100 years, and due to the rapid spread of CWD, we are concerned about the future of our deer herd and the value of our hunting land…end
Snip…
Snip…see full video presentation;
https://house.louisiana.gov/H_Video/VideoArchivePlayer?v=house/2025/Aug/0827_25_NR_Joint
FOR IMMEDIATE RELEASE: 2025-01-22 Contact: DNR Office of Communications DNRPress@wisconsin.gov
DNR ANNOUNCES PRIMARY RESULTS OF SOUTHWEST WISCONSIN CWD, DEER AND PREDATOR STUDY A deer fitted with a tracking collar walks through a wooded area during winter. The purpose of this study was to determine how CWD impacts deer populations. Photo credit: Wisconsin DNR MADISON, Wis. – The Wisconsin Department of Natural Resources (DNR) today presented the primary results of the Southwest Wisconsin Chronic Wasting Disease (CWD), Deer and Predator Study to the Natural Resources Board (NRB). A recording of the NRB meeting, including this presentation, is available on the DNR's YouTube channel.
The purpose of this study was to determine how CWD impacts deer populations. This involved estimating deer survival rates and how they were influenced by CWD.
Fieldwork for this project took place in northern Iowa, Dane and Grant counties. This area was selected for study as it is the region where CWD was first detected in Wisconsin in 2002 and has maintained a high CWD prevalence in the years since.
As part of this study, over 1,200 animals (adult deer, fawns, coyotes and bobcats) were captured, 766 GPS collars were deployed on adult deer and 323 radio tracking collars were placed on deer fawns.
Results
Scientists analyzed data from the sample of collared adult white-tailed deer in order to estimate the differences in annual survival (the probability of surviving from one year to the next) between CWD-infected and uninfected deer. Annual survival estimates are listed in the table below.
Annual Survival Probability
Uninfected CWD-Infected Females 83% 41% Males 69% 17%
These figures indicate that CWD is substantially reducing the annual survival probability of both male and female white-tailed deer. Reduced female survival lowers the growth rate of the population, and when sufficiently suppressed, may result in population decline.
Specifically, results from this study indicate that when the CWD prevalence rates of females surpasses about 29%, deer populations are expected to begin declining.
Implications
The key takeaways from these results are:
CWD substantially reduces deer survival rates and suppresses population growth. Where CWD prevalence is high, deer populations are likely declining. CWD will eventually impact deer populations elsewhere if it continues to spread and increase in prevalence. If CWD continues to spread and its prevalence continues to increase, populations will likely face further declines. The exact degree of these declines, however, will depend on local harvest and recruitment rates. It is important to note here that researchers do not expect CWD-affected deer herds to become extirpated (completely eliminated in a given area), as deer populations have a strong ability to increase reproduction when deer abundance is lower, due to less competition for food, space and other resources.
The public can learn more about these results by visiting the study’s results webpage.
Looking Forward
It should be noted that the results presented here are the primary findings of the Southwest Wisconsin CWD Deer And Predator Study. Although the scope of this study provides us with a rich dataset from which we can continue to learn about our deer herd and CWD’s impact, there are sure to be more results to come as analysis continues. Additional findings will continue to be released to the public as completed.
To stay informed about these announcements and results from additional analyses on topics like movement, habitat use and predator survival rates, subscribe to the Field Notes Newsletter.
https://dnr.wisconsin.gov/newsroom/release/103136
WISCONSIN CWD IS RAVAGING MY FAMILY’S LAND, BUT IT’S NOT TOO LATE FOR YOU
September 9, 2025 By: Paul Annear
My first season deer hunting in Wisconsin was 2001, the same season that produced Wisconsin’s first deer to test positive for chronic wasting disease. CWD has always been at the forefront of deer hunting discussions in my time as a hunter, and I’ve watched the disease slowly spread and worsen. Since 2019, eight of 11 deer I’ve taken on my family’s property in Richland County in Southwest Wisconsin have tested positive for CWD – including the buck in the photo above.
Aside from harvesting otherwise perfectly healthy-looking deer that test positive for CWD, we are now seeing live deer walking around in the awful final stages of this disease. Research has now confirmed what I’ve seen occurring on our hunting land in the last five to six years: CWD is beginning to reduce deer populations in high-prevalence areas like mine.
It didn’t have to reach this point. Hunters in areas with low CWD prevalence can keep infection rates low and deer populations healthy overall by accepting and implementing certain strategies. Some of the strategies I will lay out will challenge you as a hunter to play the “long game,” but there are ways to slow the spread of CWD in areas where it is newly discovered and infection rates are still low.
If you’re rolling your eyes at another guy talking about CWD, I get it, but I urge you to keep reading. Hear my personal story, how it has affected my hunting experiences, and what can happen if hunters ignore CWD.
“Where Are the Deer?”
…snip…see full text;
https://deerassociation.com/cwd-is-ravaging-my-familys-land-but-its-not-too-late-for-you/
This CWD Study Could Change Deer Hunting FOREVER | The Check Station October 8, 2025 NW Arkansas
NW Arkansas CWD 11:25 minutes;
50% of all deer positive for CWD.
35% of Does are Positive for CWD.
68% Bucks are Positive for CWD.
Most Bucks NW Arkansas that where Tested, are Positive for CWD.
https://m.youtube.com/watch?v=kTicUE-xsQU&t=695s&pp=2AG3BZACAQ%3D%3D
MEMORANDUM
To: Members of the Colorado Parks and Wildlife Commission
From: Dan Prenzlow, Director
Date: April 22, 2022
Subject: Chronic Wasting Disease Update for Parks and Wildlife Commission Chronic wasting disease, a fatal neurological disease found in deer, elk, and moose, is well established in herds throughout much of Colorado. We have detected CWD in 40 of our 54 deer herds, 17 of 42 elk herds, and 2 of 9 moose herds. Disease prevalence (percent infected) is highest in deer and lowest in moose. This disease is always fatal and animals die from the disease within about 2-2.5 years of infection. CWD infection shortens the lifespan of infected animals. If infection rates become too high, CWD can affect a herd’s ability to sustain itself.
Snip…
http://web.archive.org/web/20220609004350/https://cpw.state.co.us/Documents/Commission/2022/May/Item.11-PWC_Memo_CWD_Update_EckertMillerWood_April2022-Matthew_Eckert-DNR.pdf
Montana Chronic Wasting Disease CWD MANAGEMENT Announcements for 2025
HOW COULD CWD IMPACT MONTANA'S DEER AND ELK HERDS? If CWD infects enough animals, it could reduce herd numbers in the long term. Other states have seen deer population declines correlated with CWD prevalences above 20 to 40 percent. In Wyoming, some heavily infected herds of mule deer declined 21 percent per year, and white-tailed deer declined 10 percent per year. Colorado saw a 45 percent decline in mule deer in CWD-positive areas over 20 years...
“Wyoming, We estimated λ= 0.79, indicating an annual population decline of 21% under current CWD prevalence levels.”
Endemic chronic wasting disease causes mule deer population decline in Wyoming
PLoS ONE
By: Melia DeVivo, David R. Edmunds, Matthew J. Kauffman, Brant A. Schumaker, Justin Binfet, Terry J. Kreeger, Bryan J. Richards, Hermann M. Schatzl, and Todd Cornish
https://doi.org/10.1371/journal.pone.0186512
Abstract
Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting white-tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), Rocky Mountain elk (Cervus elaphus nelsoni), and moose (Alces alces shirasi) in North America. In southeastern Wyoming average annual CWD prevalence in mule deer exceeds 20% and appears to contribute to regional population declines. We determined the effect of CWD on mule deer demography using age-specific, female-only, CWD transition matrix models to estimate the population growth rate (λ). Mule deer were captured from 2010–2014 in southern Converse County Wyoming, USA. Captured adult (≥ 1.5 years old) deer were tested ante-mortem for CWD using tonsil biopsies and monitored using radio telemetry. Mean annual survival rates of CWD-negative and CWD-positive deer were 0.76 and 0.32, respectively. Pregnancy and fawn recruitment were not observed to be influenced by CWD. We estimated λ= 0.79, indicating an annual population decline of 21% under current CWD prevalence levels. A model derived from the demography of only CWD-negative individuals yielded; λ = 1.00, indicating a stable population if CWD were absent. These findings support CWD as a significant contributor to mule deer population decline. Chronic wasting disease is difficult or impossible to eradicate with current tools, given significant environmental contamination, and at present our best recommendation for control of this disease is to minimize spread to new areas and naïve cervid populations.
https://pubs.usgs.gov/publication/70192640
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186512
PLoS One. 2016 Aug 30;11(8):e0161127. doi: 10.1371/journal.pone.0161127. eCollection 2016.
Chronic Wasting Disease Drives Population Decline of White-Tailed Deer
We show that a chronic disease that becomes endemic in wildlife populations has the potential to be population-limiting and the strong population-level effects of CWD suggest affected populations are not sustainable at high disease prevalence under current harvest levels.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0161127
The effectiveness of harvest for limiting wildlife disease: Insights from 20 years of chronic wasting disease in Wyoming
First published: 21 January 2025
https://doi.org/10.1002/eap.3089
https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.3089
https://www.usgs.gov/news/national-news-release/new-study-finds-deer-hunting-can-help-keep-chronic-wasting-disease-check
How does CWD impact deer, elk, and moose populations?
Recent research in Wyoming has demonstrated declines in both mule and white-tailed deer populations in deer hunt area 65 due to CWD (see below for citations). These declines are in the core endemic area where prevalence is highest. In areas with lower prevalence, effects of CWD are poorly understood but are considered additive along with other factors that can negatively affect deer populations in Wyoming (i.e. habitat loss, predation, other diseases). The distribution and prevalence of CWD in Wyoming elk is less than that of deer. Currently there are no documented direct population impacts in Wyoming elk from CWD; however, research from Rocky Mountain National Park suggests that CWD could impact elk populations at higher prevalence (13%). While CWD has been found in free ranging moose, there have been few detections, and there is no evidence that CWD is currently having an impact on moose populations.
https://wgfd.wyo.gov/Wildlife-in-Wyoming/More-Wildlife/Wildlife-Disease/Chronic-Wasting-Disease
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
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36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011).
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The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008). snip.....
https://web.archive.org/web/20170404125557/http://webarchive.nationalarchives.gov.uk/20130822084033/http://www.defra.gov.uk/animal-diseases/files/qra_chronic-wasting-disease-121029.pdf
Chronic Wasting Disease in Texas A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 1/2025)
https://storymaps.arcgis.com/stories/b93f528938ac48e9b56dcc79953cbec0
Aug 18, 2021
Oh, Deer
Heading Off a Wildlife Epidemic
CWD poses a significant threat to the future of hunting in Texas. Deer population declines of 45 and 50 percent have been documented in Colorado and Wyoming. A broad infection of Texas deer populations resulting in similar population impacts would inflict severe economic damage to rural communities and could negatively impact land markets. Specifically, those landowners seeking to establish a thriving herd of deer could avoid buying in areas with confirmed CWD infections. As they do with anthrax-susceptible properties, land brokers may find it advisable to inquire about the status of CWD infections on properties that they present for sale. Prospective buyers should also investigate the status of the wildlife on prospective properties. In addition, existing landowners should monitor developments as TPWD crafts management strategies to identify and contain this deadly disease.
Dr. Gilliland (c-gilliland@tamu.edu) is a research economist with the Texas Real Estate Research Center at Texas A&M University.
https://www.recenter.tamu.edu/articles/tierra-grande/oh-d
Texas Kimble County Farm Chronic Wasting Disease CWD TSE Prion Approximate Herd Prevalence 12%
SUMMARY MINUTES OF THE 407th COMMISSION MEETING Texas Animal Health Commission
September 22, 2020
http://web.archive.org/web/20201017124040/https://www.tahc.texas.gov/agency/meetings/minutes/SummaryMinutes_CommMtg_2020-09-22.pdf
Thursday, October 2, 2014
TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED 79.8 percent of the deer tested positive for the disease
DES MOINES – The Iowa Department of Agriculture and Land Stewardship today announced that the test results from the depopulation of a quarantined captive deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the herd, tested positive for Chronic Wasting Disease (CWD).
http://web.archive.org/web/20141006172620/https://www.iowaagriculture.gov/press/2014press/press10022014.asp
Wisconsin Buckhorn Flats CWD
SUBJECT: Almond Deer Farm Update
Sixty of the 76 animals tested positive for CWD. The 76 deer constituted the breeding herd in the breeding facility on the farm. The property also had a hunting preserve until 2005. Four deer, two does and two fawns, the only deer remaining in the former preserve, were killed and tested as well. CWD was not detected in those animals.
The total number of deer to test positive from this farm from the initial discovery to final depopulation is 82. The nearly 80% prevalence rate discovered on Buckhorn Flats is the highest prevalence recorded in any captive cervid operation in North America.
http://web.archive.org/web/20140831060348/http://dnr.wi.gov/about/nrb/2011/december/12-11-2b2.pdf
Colorado CWD TSE Prion
“The overall incidence of clinical CWD in white-tailed deer was 82% “
Epidemiology of Chronic Wasting Disease in Captive White-Tailed and Mule Deer
http://web.archive.org/web/20150908134715/https://cpw.state.co.us/Documents/Hunting/BigGame/CWD/PDF/ResearchArticles/JWDEpiCWD.pdf
White-tailed deer population declines in a high-prevalence chronic wasting disease region of Arkansas, USA
Heather E. Gaya , Marcelo H. Jorge, Lisa A. Jorge, Mark G. Ruder, Gino J. D’Angelo, Richard B. Chandler, Michael J. Chamberlain
Published: January 7, 2026
https://doi.org/10.1371/journal.pone.0340070
Abstract
Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting cervids worldwide. CWD was first detected in Arkansas in 2015 and as of August 2025 has been detected in 24 counties across the state. Within the Tier 1 CWD management zone of northern Arkansas, average apparent CWD prevalence exceeded 25% at the onset of our study in 2021. We tested the hypothesis that high prevalence of CWD negatively affects white-tailed deer population viability. We collected data from 243 camera traps and deployed GPS-collars on 131 adult deer to monitor population dynamics. Using spatial mark-resight models, we estimated density of adult deer from 2021 to 2024 at three sites across a presumed CWD gradient to assess the impacts of high CWD prevalence on deer abundance. Deer densities declined at all three study sites, at an average 17% (95% CI: 8% − 24%) decline per year. Male densities declined by an average 23% (95% CI: 5% − 31%) per year compared to 15% (95% CI: 2% − 23%) yearly declines for females. These findings suggest that CWD can negatively impact deer populations through direct reductions in density, but additional research is needed to determine if additional factors contributed to these declines. Furthermore, our findings suggest the populations we studied are not sustainable under current harvest regulations.
snip…
Conclusion
Our findings add to a growing body of evidence that CWD can greatly alter deer populations. Given that previous research has demonstrated reductions in survival due to CWD [5], the high prevalence in our study area likely contributed to the observed population declines. However, it is possible that factors other than CWD contributed to the observed trends in deer densities. Future work in this region should document the direct effects of CWD on vital rates such as survival and fecundity to confirm the role of CWD in population declines. At present, few management tools are available to control CWD once established on the landscape. We therefore suggest that wildlife managers focus on slowing or preventing the spread of CWD to uninfected populations, taking actions that aim to stabilize or lower CWD prevalence, and collect accurate data on deer abundance to monitor when harvest limits become unsustainable.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0340070
Arkansas CWD Deer Study Final 2025
4. Objective 4 and 6 - Infection rates and population modeling
a. In 2024, CWD sample prevalence was 40% across the study area, with higher rates seen in males (65%) than in females (34%).
b. Approximately 50% of males tested positive for CWD by the age of 2.5.
c. White-tailed deer abundance in the study area declined, driven by reduced lifespans and lower lifetime reproduction.
d. If survival does not increase, this population is expected to continue to decline.
https://drive.google.com/file/d/1jN5mtvXvz7IYFDQjv4Rasrw60dGe4KMJ/view
Louisiana House of Representative Aug 27, 9:30 AM, HCR-6 CWD
Louisiana House of Representative
Chronic Wasting Disease CWD
Arkansas
Snip…
40:35 “…and conversely, I was co-Principle Investigator in NW Arkansas, where prevalence is approaching 50 percent.”
Snip…
41:00 “Specific to the work in Arkansas, in 2020, the state agency was showing the Prevalence at 30 percent in the Northwest part of the State, so flip a coin, so, 1 out of every 3 deer had the disease. We started that research in 2020, and now, the prevalence rate is now exceeding 40% in both sexes, and 50% in males.”
43:00 “what we’re seeing Arkansas now is, that population is declining about 11% a year.”
snip…
(A letter written from a Mississippi farmer who’s farm has been in his family for more than 100 years, and submitted it in this video presentation, 28 minute mark, another wake up call for sure, of what some have been warning for years, about CWD, but sadly will go by the wayside by the conspiracy theorists spreading fake news…terry)
Alston Ross
Marshall County, Mississippi
My family owns a 2,000 acre farm in Marshall County, which is in North Mississippi. CWD has plagued my farm since 2018 and has become progressively worse over time. We no longer have mature deer over the age of 3 years old on our property. Every buck harvested on our land has tested positive this year. The owners of our neighboring properties have continued to feed deer and ignore MDWFP regulations, which has exacerbated the spread of the disease throughout our area. This farm has been in my family for over 100 years, and due to the rapid spread of CWD, we are concerned about the future of our deer herd and the value of our hunting land…end
Snip…
Snip…see full video presentation;
https://house.louisiana.gov/H_Video/VideoArchivePlayer?v=house/2025/Aug/0827_25_NR_Joint
FOR IMMEDIATE RELEASE: 2025-01-22 Contact: DNR Office of Communications DNRPress@wisconsin.gov
DNR ANNOUNCES PRIMARY RESULTS OF SOUTHWEST WISCONSIN CWD, DEER AND PREDATOR STUDY A deer fitted with a tracking collar walks through a wooded area during winter. The purpose of this study was to determine how CWD impacts deer populations. Photo credit: Wisconsin DNR MADISON, Wis. – The Wisconsin Department of Natural Resources (DNR) today presented the primary results of the Southwest Wisconsin Chronic Wasting Disease (CWD), Deer and Predator Study to the Natural Resources Board (NRB). A recording of the NRB meeting, including this presentation, is available on the DNR's YouTube channel.
The purpose of this study was to determine how CWD impacts deer populations. This involved estimating deer survival rates and how they were influenced by CWD.
Fieldwork for this project took place in northern Iowa, Dane and Grant counties. This area was selected for study as it is the region where CWD was first detected in Wisconsin in 2002 and has maintained a high CWD prevalence in the years since.
As part of this study, over 1,200 animals (adult deer, fawns, coyotes and bobcats) were captured, 766 GPS collars were deployed on adult deer and 323 radio tracking collars were placed on deer fawns.
Results
Scientists analyzed data from the sample of collared adult white-tailed deer in order to estimate the differences in annual survival (the probability of surviving from one year to the next) between CWD-infected and uninfected deer. Annual survival estimates are listed in the table below.
Annual Survival Probability
Uninfected CWD-Infected Females 83% 41% Males 69% 17%
These figures indicate that CWD is substantially reducing the annual survival probability of both male and female white-tailed deer. Reduced female survival lowers the growth rate of the population, and when sufficiently suppressed, may result in population decline.
Specifically, results from this study indicate that when the CWD prevalence rates of females surpasses about 29%, deer populations are expected to begin declining.
Implications
The key takeaways from these results are:
CWD substantially reduces deer survival rates and suppresses population growth. Where CWD prevalence is high, deer populations are likely declining. CWD will eventually impact deer populations elsewhere if it continues to spread and increase in prevalence. If CWD continues to spread and its prevalence continues to increase, populations will likely face further declines. The exact degree of these declines, however, will depend on local harvest and recruitment rates. It is important to note here that researchers do not expect CWD-affected deer herds to become extirpated (completely eliminated in a given area), as deer populations have a strong ability to increase reproduction when deer abundance is lower, due to less competition for food, space and other resources.
The public can learn more about these results by visiting the study’s results webpage.
Looking Forward
It should be noted that the results presented here are the primary findings of the Southwest Wisconsin CWD Deer And Predator Study. Although the scope of this study provides us with a rich dataset from which we can continue to learn about our deer herd and CWD’s impact, there are sure to be more results to come as analysis continues. Additional findings will continue to be released to the public as completed.
To stay informed about these announcements and results from additional analyses on topics like movement, habitat use and predator survival rates, subscribe to the Field Notes Newsletter.
https://dnr.wisconsin.gov/newsroom/release/103136
WISCONSIN CWD IS RAVAGING MY FAMILY’S LAND, BUT IT’S NOT TOO LATE FOR YOU
September 9, 2025 By: Paul Annear
My first season deer hunting in Wisconsin was 2001, the same season that produced Wisconsin’s first deer to test positive for chronic wasting disease. CWD has always been at the forefront of deer hunting discussions in my time as a hunter, and I’ve watched the disease slowly spread and worsen. Since 2019, eight of 11 deer I’ve taken on my family’s property in Richland County in Southwest Wisconsin have tested positive for CWD – including the buck in the photo above.
Aside from harvesting otherwise perfectly healthy-looking deer that test positive for CWD, we are now seeing live deer walking around in the awful final stages of this disease. Research has now confirmed what I’ve seen occurring on our hunting land in the last five to six years: CWD is beginning to reduce deer populations in high-prevalence areas like mine.
It didn’t have to reach this point. Hunters in areas with low CWD prevalence can keep infection rates low and deer populations healthy overall by accepting and implementing certain strategies. Some of the strategies I will lay out will challenge you as a hunter to play the “long game,” but there are ways to slow the spread of CWD in areas where it is newly discovered and infection rates are still low.
If you’re rolling your eyes at another guy talking about CWD, I get it, but I urge you to keep reading. Hear my personal story, how it has affected my hunting experiences, and what can happen if hunters ignore CWD.
“Where Are the Deer?”
…snip…see full text;
https://deerassociation.com/cwd-is-ravaging-my-familys-land-but-its-not-too-late-for-you/
This CWD Study Could Change Deer Hunting FOREVER | The Check Station October 8, 2025 NW Arkansas
NW Arkansas CWD 11:25 minutes;
50% of all deer positive for CWD.
35% of Does are Positive for CWD.
68% Bucks are Positive for CWD.
Most Bucks NW Arkansas that where Tested, are Positive for CWD.
https://m.youtube.com/watch?v=kTicUE-xsQU&t=695s&pp=2AG3BZACAQ%3D%3D
MEMORANDUM
To: Members of the Colorado Parks and Wildlife Commission
From: Dan Prenzlow, Director
Date: April 22, 2022
Subject: Chronic Wasting Disease Update for Parks and Wildlife Commission Chronic wasting disease, a fatal neurological disease found in deer, elk, and moose, is well established in herds throughout much of Colorado. We have detected CWD in 40 of our 54 deer herds, 17 of 42 elk herds, and 2 of 9 moose herds. Disease prevalence (percent infected) is highest in deer and lowest in moose. This disease is always fatal and animals die from the disease within about 2-2.5 years of infection. CWD infection shortens the lifespan of infected animals. If infection rates become too high, CWD can affect a herd’s ability to sustain itself.
Snip…
http://web.archive.org/web/20220609004350/https://cpw.state.co.us/Documents/Commission/2022/May/Item.11-PWC_Memo_CWD_Update_EckertMillerWood_April2022-Matthew_Eckert-DNR.pdf
Montana Chronic Wasting Disease CWD MANAGEMENT Announcements for 2025
HOW COULD CWD IMPACT MONTANA'S DEER AND ELK HERDS? If CWD infects enough animals, it could reduce herd numbers in the long term. Other states have seen deer population declines correlated with CWD prevalences above 20 to 40 percent. In Wyoming, some heavily infected herds of mule deer declined 21 percent per year, and white-tailed deer declined 10 percent per year. Colorado saw a 45 percent decline in mule deer in CWD-positive areas over 20 years...
“Wyoming, We estimated λ= 0.79, indicating an annual population decline of 21% under current CWD prevalence levels.”
Endemic chronic wasting disease causes mule deer population decline in Wyoming
PLoS ONE
By: Melia DeVivo, David R. Edmunds, Matthew J. Kauffman, Brant A. Schumaker, Justin Binfet, Terry J. Kreeger, Bryan J. Richards, Hermann M. Schatzl, and Todd Cornish
https://doi.org/10.1371/journal.pone.0186512
Abstract
Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting white-tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), Rocky Mountain elk (Cervus elaphus nelsoni), and moose (Alces alces shirasi) in North America. In southeastern Wyoming average annual CWD prevalence in mule deer exceeds 20% and appears to contribute to regional population declines. We determined the effect of CWD on mule deer demography using age-specific, female-only, CWD transition matrix models to estimate the population growth rate (λ). Mule deer were captured from 2010–2014 in southern Converse County Wyoming, USA. Captured adult (≥ 1.5 years old) deer were tested ante-mortem for CWD using tonsil biopsies and monitored using radio telemetry. Mean annual survival rates of CWD-negative and CWD-positive deer were 0.76 and 0.32, respectively. Pregnancy and fawn recruitment were not observed to be influenced by CWD. We estimated λ= 0.79, indicating an annual population decline of 21% under current CWD prevalence levels. A model derived from the demography of only CWD-negative individuals yielded; λ = 1.00, indicating a stable population if CWD were absent. These findings support CWD as a significant contributor to mule deer population decline. Chronic wasting disease is difficult or impossible to eradicate with current tools, given significant environmental contamination, and at present our best recommendation for control of this disease is to minimize spread to new areas and naïve cervid populations.
https://pubs.usgs.gov/publication/70192640
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186512
PLoS One. 2016 Aug 30;11(8):e0161127. doi: 10.1371/journal.pone.0161127. eCollection 2016.
Chronic Wasting Disease Drives Population Decline of White-Tailed Deer
We show that a chronic disease that becomes endemic in wildlife populations has the potential to be population-limiting and the strong population-level effects of CWD suggest affected populations are not sustainable at high disease prevalence under current harvest levels.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0161127
The effectiveness of harvest for limiting wildlife disease: Insights from 20 years of chronic wasting disease in Wyoming
First published: 21 January 2025
https://doi.org/10.1002/eap.3089
https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.3089
https://www.usgs.gov/news/national-news-release/new-study-finds-deer-hunting-can-help-keep-chronic-wasting-disease-check
How does CWD impact deer, elk, and moose populations?
Recent research in Wyoming has demonstrated declines in both mule and white-tailed deer populations in deer hunt area 65 due to CWD (see below for citations). These declines are in the core endemic area where prevalence is highest. In areas with lower prevalence, effects of CWD are poorly understood but are considered additive along with other factors that can negatively affect deer populations in Wyoming (i.e. habitat loss, predation, other diseases). The distribution and prevalence of CWD in Wyoming elk is less than that of deer. Currently there are no documented direct population impacts in Wyoming elk from CWD; however, research from Rocky Mountain National Park suggests that CWD could impact elk populations at higher prevalence (13%). While CWD has been found in free ranging moose, there have been few detections, and there is no evidence that CWD is currently having an impact on moose populations.
https://wgfd.wyo.gov/Wildlife-in-Wyoming/More-Wildlife/Wildlife-Disease/Chronic-Wasting-Disease
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
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36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011).
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The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008). snip.....
https://web.archive.org/web/20170404125557/http://webarchive.nationalarchives.gov.uk/20130822084033/http://www.defra.gov.uk/animal-diseases/files/qra_chronic-wasting-disease-121029.pdf
Chronic Wasting Disease in Texas A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 1/2025)
https://storymaps.arcgis.com/stories/b93f528938ac48e9b56dcc79953cbec0
Aug 18, 2021
Oh, Deer
Heading Off a Wildlife Epidemic
CWD poses a significant threat to the future of hunting in Texas. Deer population declines of 45 and 50 percent have been documented in Colorado and Wyoming. A broad infection of Texas deer populations resulting in similar population impacts would inflict severe economic damage to rural communities and could negatively impact land markets. Specifically, those landowners seeking to establish a thriving herd of deer could avoid buying in areas with confirmed CWD infections. As they do with anthrax-susceptible properties, land brokers may find it advisable to inquire about the status of CWD infections on properties that they present for sale. Prospective buyers should also investigate the status of the wildlife on prospective properties. In addition, existing landowners should monitor developments as TPWD crafts management strategies to identify and contain this deadly disease.
Dr. Gilliland (c-gilliland@tamu.edu) is a research economist with the Texas Real Estate Research Center at Texas A&M University.
https://www.recenter.tamu.edu/articles/tierra-grande/oh-d
Texas Kimble County Farm Chronic Wasting Disease CWD TSE Prion Approximate Herd Prevalence 12%
SUMMARY MINUTES OF THE 407th COMMISSION MEETING Texas Animal Health Commission
September 22, 2020
http://web.archive.org/web/20201017124040/https://www.tahc.texas.gov/agency/meetings/minutes/SummaryMinutes_CommMtg_2020-09-22.pdf
Thursday, October 2, 2014
TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED 79.8 percent of the deer tested positive for the disease
DES MOINES – The Iowa Department of Agriculture and Land Stewardship today announced that the test results from the depopulation of a quarantined captive deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the herd, tested positive for Chronic Wasting Disease (CWD).
http://web.archive.org/web/20141006172620/https://www.iowaagriculture.gov/press/2014press/press10022014.asp
Wisconsin Buckhorn Flats CWD
SUBJECT: Almond Deer Farm Update
Sixty of the 76 animals tested positive for CWD. The 76 deer constituted the breeding herd in the breeding facility on the farm. The property also had a hunting preserve until 2005. Four deer, two does and two fawns, the only deer remaining in the former preserve, were killed and tested as well. CWD was not detected in those animals.
The total number of deer to test positive from this farm from the initial discovery to final depopulation is 82. The nearly 80% prevalence rate discovered on Buckhorn Flats is the highest prevalence recorded in any captive cervid operation in North America.
http://web.archive.org/web/20140831060348/http://dnr.wi.gov/about/nrb/2011/december/12-11-2b2.pdf
Colorado CWD TSE Prion
“The overall incidence of clinical CWD in white-tailed deer was 82% “
Epidemiology of Chronic Wasting Disease in Captive White-Tailed and Mule Deer
http://web.archive.org/web/20150908134715/https://cpw.state.co.us/Documents/Hunting/BigGame/CWD/PDF/ResearchArticles/JWDEpiCWD.pdf
SUNDAY, JULY 19, 2026
Texas Chronic Wasting Disease CWD TSE Prion 1,393 Confirmed Cases To Date July 2026
https://chronic-wasting-disease.blogspot.com/2026/07/texas-chronic-wasting-disease-cwd-tse.html
https://prpsc.proboards.com/thread/225/texas-cwd-prion-confirmed-date
Texas Chronic Wasting Disease CWD TSE Prion 1,393 Confirmed Cases To Date July 2026
https://chronic-wasting-disease.blogspot.com/2026/07/texas-chronic-wasting-disease-cwd-tse.html
https://prpsc.proboards.com/thread/225/texas-cwd-prion-confirmed-date
terry
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