I am posting this with the permission of Wayne Heimer, retired ADF&G Dall sheep biologist. It is based on research done by Joe Want and Mr. Heimer, and consists of Heimer's recommendations concerning current proposals #78-#91, which, unless withdrawn or amended, will be before the Board of Game at the upcoming meeting in Anchorage.
While some have claimed that this information is already public, to my knowledge it has never been posted in an online venue, and the first and only public presentation of this information was at yesterday's BGCSB meeting in Anchorage.
NOTE: The original report included additional information regarding constitutional and legal issues which Wayne asked that I not publish here. He's not being evasive about those things, it's just that the document is still in draft form and he's still working on it... but the substance of the report is here; the part that deals directly with why he believes proposals #78-#91 are flawed and should be rejected by the BOG.
2012 BOG Proposal comments—Wayne E. Heimer, Dall sheep biologist
OVERALL RECOMMENDATION: I recommend the Board reject Dall sheep season length and nonresident restriction proposals #780#91. These proposals are based on an alleged legal ram availability crisis unsupported by any objective data. Recent analysis of reported harvest data and hunter effort patterns for the last 20 years indicates there is no demonstrable legal ram availability problem which can be solved by the approaches suggested in proposals #78-#91. I reason that, because no biological or harvest allocation problem actually exists, the proposed remedies go beyond the scope of regulatory repair. If there is no real problem, the proposals are contrary to constitutionally established policies and Alaska Statutes governing allocation of the state’s resources. If the Board of Game cannot reject these proposals on these grounds, I suggest the Board consider referring them to the Department of Law for rigorous review. Alternately, the Board could refer the proposals directly to the Lieutenant Governor for conceptual certification prior to passing rather than after the fact. The legislature is the sole source of state policy. Below I offer a comprehensive review.
INTRODUCTION AND HISTORY
For 20 years, Alaska’s regulated Dall ram harvest management system has limited harvest to full-curl, double-broomed, or eight-year-old rams to safely maximize harvests in accordance with constitutional and statutory mandates. These changes were driven by coincidence of discoveries in sheep biology with federal actions that reduced (by 25 percent) the number of Dall sheep available for hunting. When Alaska’s full-curl regulation was implemented, managers required hunters report the age of each harvested ram. Nobody paid much attention to sheep harvest management for the next two decades, during which Dall sheep populations declined across most of Alaska. These population declines were apparently due to difficult weather and increased predation. Decreased hunter interest and participation followed the declines in Dall sheep population sizes.
Nevertheless, activist Dall ram hunters long for a return to “the good old days” when there were fewer guides, sheep hunting was spread over a wider area, and there was less anxiety over shooting an illegal ram. In spite of consistently high overall hunting success, this longing, coupled with the natural human inclination to instinctively explain “effect” by intuitively assuming “comfortable cause,” has led to the wide-spread notion that “Dall ram hunting has gone down the tube.” This canard’s corollary is that “We’re killing all the old rams.” By further extension, some resident hunters argue that “Nonresidents (who, by law, must have a guide) are killing all the old rams, and should be restricted to favor us (because we live here during winter).”
THE ISSUE TO BE ADDRESSED
For the 2012 regulatory cycle, there are 14 different statewide proposals (authored by nine different Alaskans APPENDIX A) before the Board of Game. These proposals place Dall sheep management in Alaska at a critical juncture.
If accepted, these proposals will radically change Dall sheep management for the foreseeable future. These proposals have in common the intuitively presumed problems that “We’re killing all the old rams.” and / or “Guides and nonresidents are killing all (or too many) of the old rams, and should be restricted to favor residents.” An objective test of this problem’s actual existence (beyond the anecdotal allegations of disappointed resident hunters) was not available until quite recently.
Recent analysis of harvest data collected over the last 20 years indicates no support for the assertion that maximal harvest is being closely approached or that “overharvest” by nonresidents materially affects resident opportunity or success. While it is true that nonresidents have a higher cumulative success rate than residents, residents consistently take approximately “half-again” as much of the available ram harvest as nonresidents (J. Want analysis). Nevertheless, the regulatory suggestions to solve this alleged but undocumented problem (which were drafted prior to development of the relevant harvest data analysis) remain on the agenda of the Board of Game.
The analytical breakthrough necessary for objectively testing the subjective impressions of hunters proposing radical changes in sheep management was driven by questions raised by commonly-alleged justifications for the proposals #78-#91. Once developed, this approach was applied to test these intuitive impressions and examine the alleged justifications for the proposals. The analysis involved use of the harvest age structures reported by hunters over the last 20 years. It allowed data-testing of these perceptions and subsequent allegations by several means. Here’s how it works:
The minimum number of legal rams present at the beginning of any hunting season can be back-calculated from the age structure of the reported harvest. These calculations began with the obvious realization that age-legal rams (beginning at age eight-years) were alive before they were killed. Since rams become age-legal at eight years (and very few survive beyond age 13-years) it was assumed that the five-year period from age eight to 13 years of age represented a reasonable harvestable “window” for rams in Alaska. Adding the total number of legal aged-rams which had to be both age-legal and alive during the five years prior to any harvest year allowed calculation of the minimum known number of age-legal rams present prior to that harvest season.
Dividing the reported harvest by the minimum known number of age-legal rams allowed calculation of the overall harvest rate (the percent of age-legal rams harvested). If it were true that “We’re killing all, or most, of the available legal rams,” this harvest percentage would have to approach 100%. If the harvest percentage does not approach 100%, the assertion must be rejected.
Knowing the age distribution of the harvest also allowed testing of the assertion that “We’re killing all the old rams” by another method. If this assertion were true, the age distribution would be heavily skewed toward younger age-legal rams in the reported harvest (because older rams would have already been killed). If the age distribution is “normally distributed,” and not heavily skewed toward younger age-legal rams, the assertion must be rejected.
A note on horn length: Use of average horn size could be used similarly, but would not allow quantitative estimation of harvest rate. If all the older rams were being harvested, the reported horn size would approach the legal minimal length, and the variation about mean horn size would decrease. If mean horn size has not decreased or variability remains consistent over time, the assertion must be rejected. Using the reported ram age structure is a better tool because it allows definition of minimal harvest rate and is less influenced by variability in horn sizes from population to population and year to year.
Percentage harvest of age-legal rams known to be present:
These analyses indicate the assertion that “We’re killing all the legal rams” must be rejected. Ram harvest rates during the first 15 years of the 20-year full-curl harvest period have ranged from 40 percent to 60 percent (with the statewide average being about 50 percent) of the minimum number of age-legal rams known to have been present. Actual percent harvests cannot be accurately calculated for the most recent four years because of the assumed five-year harvest window. Still, typically consistent “statistically normal” age distributions reported during these most recent four years suggest no changes from the previous 15 years.
Statistically normal age distributions:
Analysis of age distributions of harvested rams offers no suggestion of evidence to support the allegation, “We’re killing all the legal rams.” The age distributions of harvested Dall rams over the last 20 years remains remarkably consistent. They uniformly indicate overall normal age distributions with populations.
Interestingly, these harvested age distributions are composed of the same relative percentages of rams aged eight through 13-years as the famous “Murie” data from McKinley National Park in the late 1930s.
Are nonresidents harvesting older rams than residents?
The data indicate the allegation, “Nonresidents are killing all the big rams,” must also be rejected. The reported ram age distributions among both residents and nonresidents are identical, and have been remarkably consistent over the last 20 years.
Does hunting earlier increase chances for harvesting older rams?
The data say, “No.” Age distributions from 10-day grouped quarters of Alaska’s 42-day season show no variance within themselves over the course of the season. Surprisingly, there is no hint of difference in ram ages harvested between residents and nonresidents over the course of the last 20 hunting seasons.
What about hunting patterns?
Nothing has changed with respect to hunter effort or pattern-of-effort over the last 20 years. There has been no identifiable change in per capita days spent hunting for successful or unsuccessful hunters regardless of residency over the last 20 years.
It is widely acknowledged (and borne out by trend counts) that there are fewer sheep today than 20 years ago. Even though we still have the same dominant “open hunting” policy we have had for the last 20 years, we’re only harvesting about half of the known number of age-legal rams which had to have been available prior to the opening of sheep season each year. The relative age-distribution among harvested rams still matches that typically expected in an unhunted wild sheep population. There is no apparent advantage associated with having a guide when it comes to taking an older ram, and having an earlier hunt seems to convey no advantage in selectivity either. Notably, there has been no change in hunter effort during the last 20 years. These data indicate we must reject the notions that “We’re killing all the legal rams.” If we reject this notion, blaming nonresident hunters is not rationally allowable.
DATA ISSUES: The alleged problem does not actually exist
The available data apparently belie much of the lore and mystique associated with presumed ram availability and the size/age advantages assumed for nonresident (guided) hunters. The data also bring the presumption of hunter selectivity for more mature rams into question. There is no evidence to support the anecdotal claims that overhunting (by either residents or nonresidents) is severe enough to demand a statewide remedy.
The data also suggest that limiting nonresidents to favor resident hunters is unnecessary based on resource abundance or the impact of hunting on ram social biology. Given relatively low harvest rates (~50 percent), restrictions on nonresident participation will be more cosmetic than inherently management-effective in increasing the quality or quantity of resident hunter experiences.
Furthermore, if there is no biological problem or demonstrably resource-driven allocation disparity, the proposed remedies fall into a “forbidden zone” with respect to Alaska Constitutional directives and the Alaska Statutes.