Revision history for U.S. Geological Survey Open-File Report 2023–1015

Evaluating Elk Dynamics Around the Supplemental Feedgrounds of Wyoming to Support Management Decisions

By Cook, J.D.; Cross, PC; Tomaszewski, E.; M.Cole, E.; K.Grant, E.H. C.; Wilder, J; Runge, M.C.

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First posted online March 9, 2023

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Revised and reposted November 17, 2023, as version 2.0

Text: 
Acknowledgments: added B. Dugovich

Executive Summary: Noting that the difference in elk density between herd units with and without feedgrounds is 23 percent rather than 50 percent. Updated modeling results. Now reporting average elk counts and feeding percentages from 2016 to 2020 to align with model starting conditions rather than the 2020 or 2021 counts. Removed conclusion about differences in alternatives on mule deer and moose winter ranges that are more minor in the revision. Removed the conclusion about 60 and 40 percent population reductions with and without feeding as no longer accurate--population predictions are included in the next paragraph. 

Section 2.1 Fixed reference to table 2 so that it now appears in this section. 

Section 3.4 Noting the use of counts from 2016 to 2020 rather than just 2020 and the resulting differences in percentage of elk that are fed within a herd unit. 

Section 4.2 Altered the explanation of the two different ways we modeled transmission between fed and unfed elk within a herd unit due to a reviewer comment. 

Section 4.2 Changed the nu parameter from 2.6 to 3.0 so that models without disease maintain stable populations of elk. 

Section 4.2.1: Fixed the incorrect reference to table 3. 

Section 4.2.1: Corrected elk density estimates in table 4. The corrected elk density estimates result in different average elk densities in fed and unfed units altering the assumption about the extent to which elk may decline in the absence of feeding from 50 to 23 percent.

Section 4.2.2: Noting that in the current version the model starts with a variable number of elk based on the average and standard deviations from 2016 to 2020. 

Section 4.3: Updated modeling results. Noted how the no feeding alternative generally results in higher population sizes and hunter harvest compared to the continued feeding alternative. 

Sections 5-7 Updated modeling results. 

Figures and Tables:  

Figs. 6-20. Changed to reflect variable starting conditions and smaller reductions associated with feedground removal. 

Figs. 25, 27, 29-32. Changed to reflect variable starting conditions and smaller reductions associated with feedground removal. 

Table 1. Number of elk changed to be average number of elk from 2016 to 2020, which are used in the model as starting conditions. Removed Year from the columns. Added Gros Ventre Total, which has the counts from Patrol Cabin, Alkali, and Fish Creek because elk move among these feedgrounds often. Also added North Piney, which is a staging area that does not operate all winter. 

Table 4. Changed the winter range and density estimates. Removed the unfed and fed rows at the bottom. 

Table 5. Changed to use the average numbers from 2016 to 2020 to be consistent with table 1 and the modeling conditions. Added the standard deviation of the population estimate. Added Jackson counts. 

Tables 6-9. Changed to reflect new modeling results.