Moose Abundance and Moose Hunting in the Mcgrath Region, Interior Alaska 2001 Review

Moose Abundance and Moose Hunting in the McGrath Region, Interior Alaska 2001 Review Gordon C. Haber May 2001 State-sponsored predator control is widely viewed as a drastic, last-resort management action that should be used only rarely after passing rigorous standards of review. There are biological, ethical, and other reasons why high standards are appropriate for wolf and bear control in particular (Haber 1996). In Haber (2000, 2001), I concluded that an “adaptive management” wolf-bear control program being proposed by the Alaska Department of Fish and Game (ADF&G) and others for GMU 19D east (19De), Interior Alaska – also referred to as the “McGrath” region – had not met minimum scientific standards and was not warranted based on existing information. Control is being proposed in response to an alleged moose decline and related moose hunting problems. If and when the alleged problems are demonstrated beyond reasonable scientific doubt, it will be appropriate to address important questions about (a) their causes and (b) the alternatives for any remedial action and respective biological as well as dollar costs/benefits. Adaptive management (Walters 1986) provides a way to address resource problems in the face of uncertainty about system responses. However it does not provide a scientific license to proceed with such controversial and potentially serious, long-lasting actions as wolf and bear control when there is still major uncertainty as to whether a serious problem even exists. The McGrath proposal has yet to clear this first hurdle – demonstrating there is a serious, solvable problem - primarily because of deficient, contradictory information about moose abundance and moose harvests: Moose abundance Three moose censuses have been conducted in the McGrath region to date, all by ADF&G. In Haber (2000), I considered some of the problems with the way the first two, Feb- ruary 1996 and 1999, have been interpreted. A third census was undertaken in November 2000. This differed from the previous two not only in its timing (November vs. February) but also its larger size – 5,200 miles2 vs. 2-3,000 miles2 – and different, probably less reliable method for deriving a sightability correction. A problem noted briefly in Haber (2000) merits much more attention for all three censuses: Because of the migratory behavior of moose and 2 positioning of the census grid, all three censuses – especially in November 2000 – are likely to have excluded significant, varying migratory portions of the pertinent moose populations and/or subpopulations. Moreover, the results were probably applied to the wrong total areas to determine densities. For these reasons alone there can be little confidence in the use of the three censuses to estimate current abundance and trends or to measure responses to any future control actions. Moose, including in foothills and lowland areas north of the Alaska Range, migrate seasonally as a function of snowfall and other factors in a highly variable way for distances up to 30-40 miles or more (e.g., LeResche 1974; Haber 1977, 1988; Gasaway et al 1983; Ballard et al 1991). Little is known about moose migrations in the McGrath region except that they are significant (T. Boudreau, M. Fleagle, pers. commun. 1999, 2001) and probably closely resemble what the foregoing and other studies have reported. Seasonal migrations and shifts are especially prominent along major rivers and between foothills and lowlands. A census that excludes major segments of key drainages and/or covers a lowland area or adjacent up- lands but not both becomes highly vulnerable to error and misinterpretation. The McGrath moose censuses are subject to this uncertainty because of the way the overall census grid was delineated (the same grid [or central portions thereof] was used for all three censuses; the sampling quadrats for each census were randomly selected from within this grid). The census grid, indeed GMU 19De itself (the south boundary of which the grid follows), excludes more than half of most major drainages in the region – notably the entire upper (50%+) portions of Big River, Middle Fork, South Fork, Big Salmon Fork, Tonzona River, and Slow Fork, all of which flow into the East Fork and mid-lower North Fork of the Kuskokwim in the Nikolai-Telida area. Almost the entire upper half of the North Fork is excluded. All of the Takotna drainage is excluded, even though this constitutes about a thou- sand square miles of the total management area. These exclusions are of particular rele- vance because it is in the Nikolai-Telida-North Fork and Takotna areas where it is claimed the moose problems are most serious. It should also be noted that even though the Takotna drainage and some nearby areas have become major components of the 19D east wolf-bear control proposal they are not located within 19D east. Moose typically concentrate more in upland areas during late summer-fall, thus the November 2000 census is the most vulnerable of the three to the upstream exclusions. This further emphasizes the unreliability of the 2000 census - despite its larger size – for determining whether or not the current management goal of 3,000 moose has already been met. 3 Given the variable timing and extent of moose seasonal migrations, not even the two Febru- ary censuses are immune from this problem, although they are probably less affected. In short, ADF&G has censused undetermined, varying proportions of one or more migratory McGrath-area moose populations and/or subpopulations that use undetermined year-round ranges. From this, ADF&G argues that numbers declined from about 1,900 moose in 1996 to 1,000 in 2000 and that to generate an increase to 3,000 moose within an area of only vaguely specified size and delineation requires wolf and bear control across an 8,000 mile2 area which, like the census area, excludes upstream areas that many of the moose in question probably use on a seasonal basis. And this is happening adjacent to the 8,000-mile2 Nowitna area, where 25 years ago ADF&G initiated wolf control based on a simi- lar moose story. ADF&G claimed that Nowitna moose numbers had declined from 2,000 to 1,000 only to determine shortly thereafter from the first bona fide, drainage-wide censusing of the Nowitna that the actual number was ~3,500-5,000. The artificial boundaries of the “19De” moose census grid and of GMU 19De itself do not suffice for either research or management purposes. They preclude scientific use of the available census results in determining if wolf and bear control should proceed. At minimum, until good information is obtained on seasonal movements, censusing and management boundaries should be revised to include entire contiguous watersheds or other ecological units that delineate the year-round distribution of moose populations and subpopulations. Appendix A (bracketed portion – pp. 38-43) addresses this longstanding problem of moose censusing in greater detail, using results from stratified random sampling moose censuses in northwestern British Columbia. These examples emphasize a series of questions relating to distribution that should be asked before and after a census. They are taken from a review (Haber 1988) of a major wolf control program that also featured other moose-related mistakes being repeated at McGrath. Hence I include the entire 14 pages (29-43) of the moose section and ungulate introduction. Moose harvests Information about resident moose harvests in the McGrath region is sketchy. It is derived primarily from interviews with locals and voluntary reporting (per references in Haber 2000; see also ADF&G 2000, 2001). Recent discussions have focused primarily on claims about major 1984 to 1995 moose harvest declines in the Nikolai-Telida and Takotna areas and assumptions about related human population declines in these areas. There are also 4 samples of hunter success rates since 1992 (Haber 2000), but these are rarely if ever men- tioned. The conclusions about declining moose harvests generally ignore a key point: These are only the reported harvests. As across much of bush Alaska, the unreported annual McGrath-area resident moose harvest is known to be substantial and variable (T. Boudreau, pers. commun. 1999). With no way to determine the extent of underreporting or its year-to- year variability, there is no reliable way to use the harvest information to determine much about trends. This becomes all the more difficult in view of the likelihood of increased delib- erate underreporting. For example, in at least one area villagers prefer to hunt moose during winter rather than in the fall, because it is more difficult to keep the meat from spoiling in the fall. Winter moose harvests are now illegal, but this deters the reporting more than the hunting. Increased underreporting is also to be expected as a consequence of the passionate lo- cal drumbeat that has developed for wolf and bear control. A resident of this area now goes against a strong social grain if he or she claims anything but a moose hunting hardship. Additionally, the relatively high, statistically stable hunter success rates (Haber 2000) are contradictory. There are pitfalls in interpreting this kind of harvest information (e.g., Haber 1988: 75-88); nonetheless it provides more reason to question than to agree with the asser- tions about steeply declining total harvests. Hunter success, like depensatory predation, can remain temporarily high in the face of declining prey numbers with increased search efficiency and other adjustments. However a lag of 7-8+ years seems unlikely for the severity of the moose and harvest declines being alleged in this case. The possibility of a harvest decline of lesser severity cannot be discounted entirely. Suppose more moose were harvested in the mid 1980s.

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