Pathogen‐mediated selection and management implications for white‐tailed deer exposed to chronic wasting disease

Ketz, Alison C.; Robinson, Stacie J.; Johnson, Chad; Samuel, Michael D.

doi:10.1111/1365-2664.14109

Cited by 8 publications

(15 citation statements)

References 119 publications

(232 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, Rogers et al (2022) suggested that increased harvest of males could be effective at reducing epidemics when high CWD prevalence in males was caused by high male-to-male transmission of prions. Similarly, Ketz et al (2021) found higher susceptibility and prevalence of CWD in males and that increased harvest of male WTD could reduce the prevalence of CWD.…”

Section: Discussionmentioning

confidence: 88%

“…For example, Rogers et al (2022) suggested that increased harvest of males could be effective at reducing epidemics when high CWD prevalence in males was caused by high male‐to‐male transmission of prions. Similarly, Ketz et al (2021) found higher susceptibility and prevalence of CWD in males and that increased harvest of male WTD could reduce the prevalence of CWD. Here, we highlight the potential for elevated male‐to‐male transmission through indirect contact at scrapes; therefore, scrapes deserve more attention for research and management strategies.…”

Section: Discussionmentioning

confidence: 89%

See 1 more Smart Citation

Social network analysis of white‐tailed deer scraping behavior: Implications for disease transmission

et al. 2023

View full text Add to dashboard Cite

Host contact structure affects pathogen transmission in host populations, but many measures of host contact do not distinguish contacts that are relevant to pathogen transmission from those that are not. Scrapes are sites for chemical communication by white‐tailed deer (Odocoileus virginianus) during the breeding season and potential sites of transmission of prions, the causative agent of chronic wasting disease (CWD). Scrape‐related behaviors vary in their probability of transmitting prions to or from the environment, suggesting that behavior be combined with contact structure to better reflect potential heterogeneity in prion transmission at scrapes. We recorded visits and behaviors by deer at scrapes throughout DeSoto National Wildlife Refuge, Nebraska in 2005 and 2006. We recorded 2013 interactions by 169 unique identifiable males and 75 females. Adult males performed the most scrape‐related behaviors and spent the most time at scrapes, especially smelling the overhanging branch (70%), smelling the scrape (59%), licking/grasping the overhanging branch (44%), and scraping (36%). We used social network analysis to test the effect of behavior on indirect contact networks among deer at scrapes. By weighting edges based on the frequency and duration of behaviors, we produced networks representing sources of variation in scrape use and compared these networks to evaluate the effects of behavior on network contact structure. Social networks based on scrape‐related behavior were highly connected and dependent upon the frequency, duration, and type of behavior exhibited at scrapes (e.g., scraping, interacting with a scrape or overhanging branch, rub‐urinating, grazing) as well as the age of the deer. Accounting for contact frequency produced networks with lower variation in contact, but higher ability to facilitate contact among disparate groups. Including behavior when defining edges did not preserve the network properties of simpler measures (i.e., unweighted networks) suggesting that heterogeneity in behaviors that affect transmission probability is important for inferring transmission networks from contact networks. High connectivity through indirect contacts suggests that scrapes may be effective targets for management. Adult male deer had the highest connectivity, suggesting that management strategies focused on reducing their interaction with scrapes through density reduction or behavioral modification could reduce the connectivity of indirect contact networks.

show abstract

Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 89%

Social network analysis of white‐tailed deer scraping behavior: Implications for disease transmission

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The estimated rate of spread also provides a potential guideline for conducting monitoring in surrounding areas to detect disease spread. Increased genetic selection pressure on males and females favors a higher frequency of less susceptible deer, depending on genetically neutral hunting pressure (Ketz et al, 2022). The increasing potential for environmental prion contamination could provide a long-term source of infection exceeding that from direct contact with CWD+ deer.…”

Section: Discussionmentioning

confidence: 99%

“…Recent studies found that increased harvest of male mule deer can lead to reduction in CWD prevalence and management actions promoting an abundance of mature male deer likely contribute to rapid growth of CWD prevalence (Conner et al, 2021;Miller et al, 2020) and higher transmission rates in males. A better understanding of male transmission would be beneficial to the development of alternatives to current CWD management recommendations focused on reducing male abundance to reduce CWD prevalence and transmission (Jennelle et al, 2014;Ketz et al, 2019Ketz et al, , 2022Miller et al, 2020;Samuel & Storm, 2016).…”

Section: Discussionmentioning

confidence: 99%

“…Prevalence increased over time and varied considerably among monitoring areas (Appendix S1). Because previous studies found similar infection rates for male and female yearlings (Ketz et al, 2022;Samuel & Storm, 2016), yearlings were not separated by sex. Although CWD testing was initiated in all monitoring areas in 2002, the highest amount of testing occurred in the Northcentral Iowa County and Core monitoring areas, where CWD was discovered in 2001.…”

Section: Cwd Prevalencementioning

confidence: 99%

See 1 more Smart Citation

Spatiotemporal epizootiology of chronic wasting disease in Wisconsin deer

Samuel

2023

Ecosphere

Self Cite

View full text Add to dashboard Cite

Chronic wasting disease (CWD) is a fatal neurological disease of cervids caused by a misfolded protein with no vaccines or other cures to prevent infection and death. In the past decade, CWD has been recognized as one of the 10 most important challenges facing wildlife management. This paper evaluates the temporal and spatial patterns of CWD prevalence in southern Wisconsin white‐tailed deer during the past 20 years. In most CWD areas, prevalence progresses from introduction to enzootic equilibrium in 15–20 years. In some monitoring areas, the disease grows at a much slower rate and remains below the equilibrium levels. Outbreaks are characterized by four distinct epizootic stages. Disease establishment (Stage 1) depends on the distance from a CWD focus. High rates of incidence and prevalence growth (Stage 2) are followed by slower growth as the relative number of susceptible deer declines (Stage 3). The rate of prevalence increase over time is higher in more forested ecoregions and in males (0.48 vs. 0.43) but similar in females (0.43 vs. 0.37) and yearlings (0.44 vs. 0.39). Habitat features, acting as surrogates for deer behavior and contact, may affect the rate of prevalence growth at a landscape (ecoregion) scale. Additionally, prevalence may be affected by deer management practices that favor higher deer abundance and more mature males. Finally, enzootic equilibrium (Stage 4) is higher in males (0.5), followed by females (0.36) and then yearlings (0.26). These equilibrium prevalence levels are high enough to have significant population impacts, reduce the abundance of mature males, and facilitate CWD spread by infected yearlings. Epizootic patterns suggest that CWD transmission has been frequency‐dependent and primarily driven by direct contact with infected deer. Evidence for a meaningful change in the epizootic pattern from a 10‐year management program to reduce deer abundance is lacking. The trajectory of CWD dynamics in Wisconsin suggests rapid growth in regional prevalence following introduction and increased spread across the landscape.

show abstract

Evidence of limited short‐term adverse demographic side effects of chronic wasting disease management

Mysterud,

Van Moorter,

Viljugrein

et al. 2024

J Wildl Manag

View full text Add to dashboard Cite

Competing objectives are common in the management of wildlife diseases. However, the extent to which disease mitigation conflicts with other goals has rarely been quantified. Chronic wasting disease (CWD) is a lethal cervid disease widely distributed in North America and recently detected in Europe. After the detection of CWD among reindeer (Rangifer tarandus) in Norway in 2016, intensified and male‐biased harvesting was used to manage CWD, but this may have adverse side effects. Based on extensive surveillance data (2001‒2022) gathered by the Norwegian Institute for Nature Research (NINA) and local management in addition to harvest statistics, we quantified how CWD management in Hardangervidda, Norway, changed harvest rates and affected population size, operational sex ratio, and age structure, and, in turn, whether recruitment, sex ratio of calves, and calving dates were affected. We used a formal reindeer quality standard to define adverse management. The estimated harvest rate of adult males reached >40% annually; however, the population size was only moderately reduced because the harvest of adult females was similar or decreased. The sex ratio changed from approximately 1:2.2 to 1:6.5 (males ≥3 years: females ≥1 year), which brought the population from good to poor quality according to the reindeer quality standard. The proportion of prime‐aged (≥5 years) males among adult males (≥2 years) in the harvest decreased from >60% to approximately 30%. Demographic changes led to limited side effects in the short‐term, with a delay of 4‒5 days in calving dates and a slightly more female‐biased sex ratio among the harvested calves but without a marked change in early recruitment. Wildlife populations are increasingly threatened by severe disease outbreaks that may require intensive management. Our study highlights the importance of extensive surveillance to document the potential adverse effects on population abundance, demography, and demographic side effects. The fairly limited short‐term adverse impacts can be traded against a higher likelihood of future sustainability without severe diseases; however, this may become an issue of concern if the disease becomes endemic. Balancing these trade‐offs would benefit from good communication between veterinary sciences and wildlife ecology experts.

show abstract

Pathogen‐mediated selection and management implications for white‐tailed deer exposed to chronic wasting disease

Cited by 8 publications

References 119 publications

Social network analysis of white‐tailed deer scraping behavior: Implications for disease transmission

Social network analysis of white‐tailed deer scraping behavior: Implications for disease transmission

Spatiotemporal epizootiology of chronic wasting disease in Wisconsin deer

Evidence of limited short‐term adverse demographic side effects of chronic wasting disease management

Contact Info

Product

Resources

About