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An evaluation of moose harvest management in central and northern British Columbia.

ABSTRACT: Moose (Alces alces) harvest strategies employed within 19 Game Management Zones (GMZ's) of central and northern British Columbia during the mid-1990's were reviewed and evaluated. Passive harvest controls, including long bull-only seasons, were primarily used in northern GMZ's where moose densities and hunting pressure was low, and predator populations were lightly exploited. A mix of passive and active harvest controls for bulls, cows, and calves were used in most of the remaining GMZ's where moose densities and hunting pressure were higher. The effectiveness of the various harvest controls were evaluated from 5 performance indicators. Overall, the harvest strategy that sustained the greatest hunting pressure, harvest density, and harvest rates, while maintaining desired hunting effort and post-season bull/cow ratios, was the strategy employed within the Omineca Sub-Region. This strategy provided a general open season to harvest spike-fork or "immature" bulls and calves, combined with a limited entry hunting season for mature bulls and cows. Several preliminary yield-density curves were proposed. Where predator populations were reduced through hunting and trapping, moose harvests ranged from 22 kills/1,000 [km.sup.2] at a post-season density of 300 moose/1,000 [km.sup.2] to 53 kills/1,000 [km.sup.2] at 700 moose/1,000 [km.sup.2] Moose harvest management was hindered by insufficient survey data, lack of reliable estimates of non-hunting mortality rates, and incomplete information on unregulated harvests. In British Columbia, moose management objectives should focus on maintaining appropriate adult sex ratios, providing a diversity of hunting opportunities, and optimizing recreational days per moose harvested, as opposed to traditional objectives associated with population size, harvest, hunter numbers, and hunter days which have either not been achievable or measurable.

ALCES VOL. 35: 91-103 (1999)

Keywords: active controls, dices, harvest strategy, passive controls, population management, yield-density curves

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British Columbia (BC) has developed a variety of moose harvest strategies in response to varying population characteristics and ecological conditions, hunting pressure, and regional stakeholder desires. These strategies have been used to regulate harvests, distribute hunting pressure, and control success rates. Timmermann and Buss (1998) indicated that harvest strategies can be classified as either "passive" or "active" controls. Passive controls usually affect all hunters equally, do not directly impact individuals, and allow unlimited numbers of hunters. Active controls directly affect individuals by limiting hunter numbers and hunting opportunities. In BC, passive controls include a general open season (GOS) which manipulates the season length and timing, and may also include area closures and access restrictions. Active controls include limited entry hunting (LEH) where hunters must successfully draw a permit in a lottery to hunt a specified sex and age class of animal in a designated area. The objective of both active and passive controls is to affect or control the number of moose harvested, and thereby the population through selective harvest of a predetermined annual allowable harvest.

In this paper, I review the moose harvest strategies employed during the mid-1990's in central and northern BC, and evaluate the effectiveness of these strategies from 5 performance indicators. Preliminary yield-density curves are presented and new management objectives for moose are proposed.

STUDY AREA

Central and northern BC comprises approximately 700,000 [km.sup.2], of which about 550,000 [km.sup.2] are occupied by moose. The area is ecologically diverse and incorporates a variety of climatic, physiographic, and ecological factors that affect moose productivity, habitat requirements, and consequently, management prescriptions. In recognition of this diversity, 6 moose ecotypes or geographic regions were identified by Eastman and Ritcey (1987) to facilitate management. Administration is currently through 4 regions and sub-regions comprising 19 Game Management Zones (GMZ's, Fig. 1). GMZ's (range: 13,727 [km.sup.2]--61,269 [km.sup.2]) are amalgamations of Wildlife Management Units (WMU' s, range: 788 [km.sup.2]--18,983 [km.sup.2]) which share similar ecological characteristics (consisting predominately of 1 ecotype) and hunter harvest patterns, and thus provide a suitable geographical framework for implementing management strategies.

[FIGURE 1 OMITTED]

Moose hunting is important provincially for sustenance, cultural, and recreational needs. The priorities for allocation of moose in British Columbia are: first priority--aboriginal use as prescribed in law; second priority--resident use; third priority--nonresident use (MELP 1996). Moose are also important economically. In 1995, the value of resident moose hunting was estimated to be $15,822,940 (Reid 1997).

In recent years, moose harvests and hunter days have declined in central and northern BC. From 1988-1990, an average of 12,070 moose were harvested annually which provided an average of 276,291 hunter days of recreation each year. During 1991-1993 the harvest averaged 10,242 (250,918 days) and from 1994-1996 it averaged 9,111 (209,902 days). Current populations are generally depressed from peak levels in the 1960's, primarily because of the declining incidence of wildfire, unregulated harvests, and predation (Hatter, unpubl. report). Both past and present forestry practices have affected moose habitat, but the benefits and extent of these effects have varied throughout the province.

METHODS

Estimation of Harvest and Population Size within WMU's

Hunter harvest.--Harvest statistics, including total harvest, sex-age composition, hunter numbers, and hunter days have been estimated annually for each WMU since 1976. These variables were derived from a moose harvest questionnaire mailed to a random sample of hunters, with a follow-up second questionnaire sent to non-respondents. Approximately 50% of the moose hunters received the questionnaire, with an initial compliance rate of about 60% and a 15% compliance rate for the second mailing. Hunting pressure was calculated as resident hunter days/1,000 [km.sup.2] of habitable moose range (DPUA) while harvest density was resident and non-resident kill/ 1,000 [km.sup.2] (KPUA). Hunting effort was resident hunter days/moose (DPK). Kill per unit effort (KPUE) was calculated as the number of moose harvested by resident hunters/100 hunter days. The annual rate of population change ([lambda]) was calculated from [log.sub.e](kills/100 days) versus year (Van Ballenberghe 1983) and incorporated a harvest vulnerability exponent to account for a non-linear relationship between KPUE and abundance (Hatter 1998).

Moose population surveys.--Winter (Dec-Mar) surveys of absolute abundance were conducted periodically, based on an aerial stratified random block (SRB) sampling design for moose (Gasaway et al. 1986). Moose survey areas (SA's) generally ranged from 1,000 to 5,000 [km.sup.2] and included one or more WMU's. Since 1990, about 65 SRB surveys have been conducted. Classification included identification of bulls, cows, and calves. Most surveys did not include an independently derived sightability correction factor (SCF) to correct for under-counting bias, although SCF's were subjectively estimated to range between 1.1 and 1.5 (Hatter unpubl. report). Rate of change from repeat surveys was calculated as [lambda]=[([N.sub.t]/[N.sub.0]).sup.1/t], where [N.sub.t] is the number of moose in year t, and [N.sub.0] is the number of moose in the initial or first survey year (Van Ballenberghe 1983). In the Omineca Sub-region, only 3 SRB surveys were conducted. Consequently, annual herd composition surveys were also used to estimate winter sex ratios (bulls/100 cows) and calf recruitment (calves/100 cows).

Estimation of Population Status within GMZ's

Numerous WMU's were not surveyed for density and composition. Thus, moose densities from SA's were extrapolated to estimate the density within a GMZ. The reliability of these extrapolations was variable depending upon the number of WMU's surveyed and homogeneity in moose population parameters within a GMZ.

Moose population model.--A simple balance model or "annual life equation" was developed to estimate post-season population size, rate of change, and harvest rate for moose within each GMZ. The population model was partitioned into post-season bulls (B), cows (C), and calves (Ca). The model consisted of the following interdependent equations:

[B.sub.t] + 1 = [B.sub.t][Sa.sub.b] + 0.5([Ca.sub.t]Sj) - H[(B).sub.t],

[C.sub.t] + 1 = [C.sub.t][Sa.sub.c] + 0.5([Ca.sub.t]Sj) - H[(C).sub.t],

and

[Ca.sub.t] + 1 = [[C.sub.t][Sa.sub.c] + 0.5([Ca.sub.t][S.sub.j])](Ca/ C)-H[(Ca).sub.t],

where H[(B).sub.t], H[(C).sub.t], and H[(Ca).sub.t], were the average bull, cow, and calf harvests respectively. [Sa.sub.b], [Sa.sub.c], and [S.sub.j] were the bull, cow, and calf winter survival rates. [Sa.sub.c] was estimated from repeat SRB surveys on SA's, where available, using the method described by Hatter and Bergerud (1991). [Sa.sub.b] was assumed to be either 0.85 or 0.88. Sj was estimated as 0.95x[Sa.sub.c] (Larsen et al. 1989). Ca/C was the pre-season calf/ cow ratio. An equal calf sex ratio was assumed (Boer 1992). Harvest estimates were increased by 20% to incorporate additional losses due to wounding (Fryxell et al. 1988).

The population model was used to check the inventory-extrapolated population estimates by determining if the known harvests produced post-season sex and age ratios and an annual rate of change that were consistent with SA and KPUE results. If the inventory estimate failed to provide a reasonable fit it was iteratively adjusted by the model until the above parameters more closely matched those from the SA's and KPUE. The harvest rate (Mb) was harvest/(harvest + post-season population). The population density was post-season moose/ 1,000 [km.sub.2]. Due to errors in estimation of [lambda], and because of natural population fluctuations, harvests or "yields" were considered sustainable if the modelled estimate of [lambda] ranged between 0.97 and 1.03.

Evaluation of Harvest Strategies

Five performance indicators were used to evaluate moose harvest strategies. These included hunting pressure (days/1,000 [km.sub.2]), harvest density (kills/1,000 [km.sub.2]), hunting effort (days/kill), adult sex ratio (bulls/100 cows), and harvest rate (Mh). In the following comparisons, the average values from 1994-1996 were used, except for the Peace-Liard, where 1993-1995 averages were used. This was because a new harvest strategy was introduced in 1996, which markedly changed these parameters from previous years.

RESULTS AND DISCUSSION

Review of Regional Harvest Strategies

Harvest controls varied between GMZ' s, but generally were consistent within a GMZ (Table 1). Passive harvest controls, which included long bull open seasons, were primarily used in northern GMZ's where moose densities, calf recruitment, and hunting pressure were low and predator populations were lightly exploited (Table 2). A mix of passive and active harvest controls for bulls, cows, and calves were used in most of the remaining GMZ's where moose densities and hunting pressure were higher; and predator population' s were more heavily exploited through hunting, trapping, and problem animal control on agricultural lands. More opportunities for antlerless hunting were provided within those WMU's where calf recruitment was higher.

Cariboo Region (GMZ's 5ab, 5c-5e).--The Cariboo adopted a harvest strategy in 1993 to recover low density moose populations and improve bull/cow ratios. Passive controls included a short post-rut (Oct 15-31) GOS for bull moose in GMZ's 5ab, 5c, and 5d. There was no GOS for moose within GMZ 5e, as moose densities were extremely low (~25 moose/1,000 [km.sub.2]). Active controls included pre-rut (Sep 10-26), rut (Sep 27-Oct 14), and early winter (Nov 1-15) limited entry hunts for bulls. Antlerless seasons were reduced, although GMZ's 5ab and 5c continued to provide some antlerless LEH opportunities. In 1993, resident harvests were reduced by 48% (GMZ 5ab)--57% (GMZ 5d) but harvests steadily increased thereafter. The harvest proportion averaged 97% bulls and 3% cows. Moose numbers appeared to stabilize in GMZ 5ab and 5c, while numbers may have increased in GMZ 5d. SA's within GMZ 5ab showed some improvement in bull/cow ratios, although sex ratios in most SA's remained below 30 bulls/100 cows. Modelled estimates of bull/cow ratios, however, were slightly higher (Table 2).

Skeena Region (GMZ's 6b-6f).--Skeena maintained relatively constant hunting regulations from 1993-96, although different controls were employed within different GMZ's. On the coast, GMZ 6b employed relatively short to long GOS's (Oct 20-Nov 5 or Sep 10-Nov 15), depending on access and hunting pressure within individual WMU's. Due to very low densities (<100 moose/1,000 [km.sup.2]), there was no antlerless season in this zone. GMZ 6c was the most heavily hunted zone. In 1993, a relatively short GOS for bulls (Oct 26-Nov 5) in this zone, combined with pre-rut/rut (Sep 10-Oct 19) and early winter (Nov 1-15) LEH seasons, were implemented to improve bull/cow ratios. WMU's with moose densities on winter ranges exceeding 800 moose/1,000 [km.sup.2] maintained a short antlerless and calf LEH season. This strategy initially reduced resident moose harvests by 43%, but harvests steadily increased thereafter. The harvest proportion averaged 73% bulls, 13% cows, and 13% calves. Despite the harvest controls, winter bull/cow ratios remained relatively low (33-35 bulls/100 cows) while calf/cow ratios declined from 38/100 in 1992 to 33/100 in 1997. GMZ's 6e and 6fwere lightly hunted and had a long GOS for bulls (Aug 15-Nov 15). Winter bull/cow ratios consistently exceeded 50 bulls/100 cows within these SA's. Moose numbers appeared stable in GMZ 6c, 6d, and 6f, while numbers appeared to have declined in GMZ 6b and 6e (Table 2).

Omineea Sub-region (GMZ's 7Oa-7Oe).--Omineca initiated a selective harvest strategy in 1981 that utilized both active and passive controls within GMZ's 7Oa-7Od. This strategy was comprised of a GOS for spike-fork bulls (predominately yearling bulls having no more than 1 or 2 points on 1 antler) with an any-bull LEH season, a calf GOS, and an antlerless LEH (Child 1983). The antlerless LEH season included both an early (Oct) and late (Nov-Dec) season. With the exception of 1986-1990 when a short, post-rut GOS for bulls was offered, this strategy appears to have sustained high harvests (comparable to pre1981 harvest levels in GMZ's 7Ob and 7Od), high hunting pressure, and stable moose numbers within most GMZ's. The harvest composition averaged 64% bulls, 19% cows, and 18% calves. Moose density was lower in GMZ 7Oe (148/1,000 [km.sup.2]), but was lightly hunted and offered a bull-only GOS extending from Aug 15-Nov 5. Moose numbers appeared relatively stable in GMZ's 7Oa-7Od, although herd composition surveys in 1996 indicated a drop in calf recruitment in 7Ob (32 calves/100 cows compared to previous surveys of 40-50 calves/100 cows) and low calf recruitment in 7Oc (20 calves/100 cows). Despite the recent decline in recruitment, there was no harvest-related evidence (e.g., declining hunter success or kill per unit effort) to suggest population size had changed substantially over the last decade.

Peace-Liard Sub-region (GMZ's 7Pa-7Pe).--Prior to 1996, the basic bull harvest strategy employed within the Peace-Liard was a GOS starting Aug 15 with the length of the season dictated by hunting pressure. From 1991-1995 the bull moose season extended from Aug 15-Sep 21 in most WMU's of GMZ 7Pb; while GMZ's 7Pa, 7Pc, and 7Pc also included a post-rut season (Oct 16-31). In GMZ 7Pd, where hunting pressure was light (4.9 kills/ 1,000 [km.sup.2]), the season extended from Aug 15-Oct 31. A GOS for calves was available for a limited number of WMU's (primarily within GMZ 7Pb), but was eliminated in 1996, following an unusually severe winter in 1995-96. The harvest composition in GMZ 7Pb, where some WMU's had a GOS for calves and a LEH season for cows, was 67% bulls, 9% cows, and 24% calves. Moose numbers appeared stable in GMZ 7Pa, 7Pb, 7Pd, and 7Pe while numbers were declining within GMZ 7Pc. Adult sex ratios were relatively low in GMZ 7Pa (22 bulls/100 cows), 7Pb (30 bulls/100 cows), and GMZ 7Pc (27 bulls/100 cows). Moose densities were lowest within GMZ 7Pd (200 moose/ 1,000 [km.sup.2]) and 7Pe (216 moose/1,000 [km.sup.2]), but because of light hunting pressure, had higher bull/cow ratios (Table 2).

In 1996, a new bull harvest strategy (Spike-Or-Fork-Tripalm or SOFT) was implemented throughout the sub-region. Under this strategy, any bull moose was available for harvesting from Aug 15-31. Spike-fork bulls (bulls with no more than 2 points on 1 antler) and tri-palm bulls (bulls having 3 or more points on 1 brow palm) were legal from Sep 1-Oct 31, except within the more heavily hunted WMU's where a rut closure (Oct 1-Oct 15) was maintained. Resident hunter days declined by only 4% from 1995 (47,364 days) to 1996 (45,673 days), even though the harvest declined from 2,500 to 1,365. This slight reduction in hunter days indicated that resident hunters spent more timing hunting for each moose harvested under the first year of the SOFT strategy. In the second year of the SOFT strategy (1997), hunter days declined to 35,054 while the moose harvest increased slightly to 1,434.

Evaluation of Moose Harvest Strategies

Hunting pressure.--Hunting pressure increased linearly with moose density ([R.sup.2]=0.67, F=36.7; 1, 18 df; P<0.001, Fig. 2). The greatest hunting pressure occurred within GMZ 7Ob (1,974 days/1,000 [km.sup.2]) and GMZ 7Oc (989 days/1,000 [km.sup.2]). GMZ 5ab produced 767 days/1,000 [km.sup.2], followed by GMZ 7Oa (668 days/1,000 [km.sup.2]), 7Pb (546 days/1,000 [km.sup.2]), 7Pa (535 days/1,000 [km.sup.2]), and 7Pc (517 days/1,000 [km.sup.2]). The high hunting pressure within GMZ 7Ob and 7Oc indicated that the "Omineca" strategy was effective in maintaining a high level of recreational hunting. This was partially because approximately 3 times as many days were required to harvest a spike-fork bull or calf during a GOS than a bull or cow during a limited entry hunt (Child and Aitken 1989).

[FIGURE 2 OMITTED]

Harvest density.--Harvest density also showed a strong relationship to moose density ([R.sup.2]=0.87, F=115.4 ; 1, 18 df; P<0.001, Fig. 3). As with hunting pressure, the Omineca Sub-region produced the highest harvests in 7Ob (67 kills/1,000 [km.sup.2]) and 7Oc (40 kills/1,000 [km.sup.2]). GMZ's 7Pb and 7Pc produced 38 and 35 kills/1,000 [km.sup.2], respectively. Harvests dropped substantially with the implementation of the SOFT strategy in the Peace-Liard in 1996 (e.g., GMZ 7Pb; 38 kills/1,000 [km.sup.2] from 1993-95 vs. 27 kills/1,000 [km.sup.2] in 1996: GMZ 7Pc; 35 kills/1,000 [km.sup.2] from 1993-95 vs. 20 kills/ 1,000 [km.sup.2] in 1996).

[FIGURE 3 OMITTED]

Hunting effort.--Current management guidelines recommend maintaining between 25 and 35 days per harvested moose (Hatter, unpubl. report). The Cariboo (GMZ's 5ab, 5c, and 5d) and Omineca (GMZ's 7Oa, 7Ob, 7Oc, and 7Od) met the proposed management guidelines, while Skeena provided less than 25 days/kill in all GMZ's (Table 2). Prior to implementing the SOFT strategy, the Peace-Liard Sub-region also provided less than 25 days/kill in all GMZ's. However, after implementing the strategy in 1996, DPK rose substantially in 7Pa (52 days/kill) and 7Pd (49 days/kill). Increases were also observed in 7Pb (23 days/kill), 7Pc (31 days/kill), and 7Pc (32 days/kill).

Adult sex ratios.--BC's provincial Wildlife Harvest Strategy recommends maintaining at least 30 bulls/100 cows postseason (MELP 1996). Post-season bull/ cow ratios were below 30 bulls/100 cows within GMZ's 5ab, 7Pa, and 7Pc (Table 2). Adult sex ratios exceeded 50 bulls/100 cows within GMZ's Se, 6e, and 6f (Table 2).

Harvest rate.--The highest harvest rates (~8.5%) were observed in the Omineca (GMZ 7Ob and 7Od), while the lowest rates ([less than or equal to] 3.0%) occurred in the northern GMZ's. These harvest rates, while comparable to rates in the Yukon and Alaska, were substantially less than those reported for other North American jurisdictions (Crete 1987). Not all of the harvest rates were sustainable. GMZ's 6b, 6e, 7Oe, and 7Pc had [lambda] < 0.97 and their harvests were not considered sustainable.

Overall, the harvest strategy employed in the Omineca, particularly within GMZ's 7Ob and 7Oc, sustained the highest hunting pressure, harvest density, and harvest rates, while meeting the provincial guidelines for hunter kills/day and post-season adult sex ratios. Harvest strategies employed in other administrative regions generally had lower bull/cow ratios and required more frequent changes to moose hunting regulations as populations declined. With only 2 years of information available, it was not possible to determine the long-term effectiveness of the SOFT strategy in the Peace-Liard. However, implementation of a similar strategy on the Kenai Peninsula improved bull/ cow ratios and is now supporting almost as many hunters as prior to implementation of the strategy (Schwartz et al. 1992, T. H. Spraker, Alaska Dept. Fish and Game, Soldotna, pers. comm.). In that study the harvest dropped by 48% following the first year of the new regulation, but increased thereafter. In the Peace-Liard, the harvest dropped by 45%, but increased by 5% during the second year.

MANAGEMENT IMPLICATIONS

Yield-density curves.--Yield-density curves for moose vary greatly between predator-free areas and areas where predator populations are present (Crete 1987, Gasaway et al. 1992). The carrying capacity (K) for moose in multi-ungulate systems in western North America, where predators are absent, is believed to be [greater than or equal to] 1,500 moose/1,000 [km.sup.2] (Bergerud 1992); whereas in multi-ungulate systems with predators (i.e., wolves and bears), K likely ranges between 150 moose/1,000 [km.sup.2] (Gasaway et al. 1992)to 300 moose/1,000 [km.sup.2] (Bergerud 1992). The maximum rate of increase for moose observed in northern boreal ecosystems was approximately 15%/year (Van Ballenberghe and Dart 1982, Boertje et al. 1996) and the maximum sustained yield level for moose appears to occur at 60% of K (Crete et al, 1981). These parameters suggest a MSY of 95 moose/1,000 [km.sup.2] could be achieved from a post-season population size of 800 moose/1,000 [km.sup.2] in predator-free areas (Mb = 11%, Fig. 4). Conversely, in areas with lightly hunted predator populations, a MSY of 14 moose/1,000 [km.sup.2] should occur at a post-season population of 120 moose/1,000 [km.sup.2] (Mh = 10%, Fig. 4). Observed average harvests of moose within 14 GMZ's, where moose numbers were relatively stable (0.97 [less than or equal to] [lambda] [less than or equal to] 1.03), were substantially less than those predicted by the theoretical "predator-free" yield curve. While the yield-density curve for moose with lightly exploited predator populations did provide a reasonable fit to harvest densities from northern BC (GMZ's 6d, 6f, 7Pd, and 7Pc), they were inadequate to verify the MSY. Gasaway et al. (1992: 44) suggests that the maximum harvest rate for moose in these systems is approximately 5%.

[FIGURE 4 OMITTED]

A sustained yield curve for moose was empirically derived for the 10 GMZ's where moose densities were relatively stable and predator populations were presumed to be more highly exploited ([R.sup.2]=0.89, F=71.4; 1,9 df; P<0.001, Fig. 4). This yield curve indicated that harvests increased with density, and was similar to the yield-density curve for moose with harvested-limited predator populations in Alaska and the Yukon (Gasaway et al. 1992:44). Sustainable harvests of moose ranged from 22 kills/1,000 [km.sup.2] at a post-season density of 300 moose/ 1,000 [km.sup.2] (Mb = 6.8%) to 53 kills/1,000 [km.sup.2] at 700 moose/1,000 [km.sup.2] (Mh = 7.0%). Actual harvest densities would be higher as the harvest estimates only included resident and non-resident hunting, and excluded harvests by First Nations and other non-reported mortalities (e.g., poaching) that were likely substantial in most GMZ's. This yield-density curve suggests that increasing moose densities may be more effective for increasing yields than restructuring the sex and age composition of the harvest.

Co-ordination of moose hunting regulations.--BC has evolved a relatively complex set of moose harvest regulations, involving numerous passive and active controls (Table 2). Consequently, co-ordination of moose hunting regulations has and continues to be an on-going management issue. While a single provincial strategy may not adequately address all conservation needs and meet the various demands and expectations from hunters, it should be possible to reduce the variety of active and passive controls currently employed in BC. The "Omineca" strategy could probably be successfully implemented in other GMZ's. However, variations in habitat quality, predator densities, and winter severity would necessitate adjusting the proportion of bulls, cows, and calves harvested. In low density populations with low recruitment, such as GMZ 7Pd and 7Pe, there would probably be little benefit to harvesting any antlerless moose. This is supported by modelling and empirical studies of similar systems in Yukon and Alaska which suggest bull-only hunting can provide near equivalent yields as either-sex hunting (Van Ballenberghe and Dart 1982, Gasaway etal. 1992, Boertje et al. 1996). The SOFT strategy employed in the Peace-Liard may provide another alternative to the "Omineca" bull moose strategy, by offering unlimited hunter participation for legal mature bulls.

Establishing management objectives.--Previous moose policy statements for British Columbia and other jurisdictions have developed management objectives pertaining to moose population size, harvest, hunter numbers, and hunter days (Munro and Petticrew 1979, Timmermann and Buss 1998). However, experience in BC has shown that without effective predator and habitat management, it generally has not been possible to meet the population and harvest objectives (Hatter, unpubl. report). Insufficient survey data, lack of reliable non-hunting mortality estimates, and inadequate information on unregulated harvests also make it difficult to determine if these objectives are being met. In addition, hunter numbers and days in BC appear to be declining from numerous causes (MELP 1996), and are no longer simply related to hunting opportunities. Finally, most wildlife management agencies are now adopting an ecosystem management approach, where moose are viewed as a component of ecosystems (Hatter, unpubl. report). Management objectives to enhance moose for greater yields may be inappropriate if higher moose densities have a detrimental impact on other species. For example, objectives to increase moose populations in southern BC may have contributed to declines in sympatric mountain caribou populations by sustaining greater numbers of wolves that preferentially prey on caribou during the summer months (Seip 1992).

It is recommended that BC establish new objectives for moose which are both achievable and measurable under current fiscal constraints; and which place wildlife conservation and ecosystem management as the highest priority. Management objectives should focus on maintaining appropriate adult sex ratios, providing a diversity of hunting opportunities and optimizing recreational days per moose harvested, as opposed to traditional measures associated with population size, harvest, hunter numbers, and hunter days.
Table 1. Harvest controls used in Wildlife Management Units (WMU's)
within Game Management Zones (GMZ's) in 1996, except for GMZ's 7Pa--e
which are for 1995.

 General Open Seasons

GMZ Class Season Dates WMU's

5ab Bulls: Oct 15-Oct 31 501,502,515
5c Bulls: Oct 15-Oct 31 510,512-514
5d Bulls: Oct 15-Oct 31 503-504,505-506
5e n/a 511
6b Bulls: Sep 10-Nov 15 603,611,614,616
 Bulls: Oct 20-Nov 5 610,615
6c Bulls: Oct 20-Nov 5 601-602,604-606,
 608-609
6d Bulls: Oct 20-Nov 5 607,630
 Bulls: Aug 15-Nov 15 617-618
6e Bulls: Aug 15-Nov 15 619-624
6f Bulls: Aug 15-Nov 15 625-629
7Oa SF Bulls: Sep 10-Nov 5 701-705,717-718
 Calves: Oct 10-Oct 25
7Ob SF Bulls: Sep 10-Nov 5 706-713,715
 Calves: Oct 10-Oct 25
7Oc SF Bulls: Sep 10-Nov 5 714,716,723-726
 Calves: Oct 10-Oct 25
7Od SF Bulls: Sep 10-Nov 5 727-730,738
 Calves: Oct 10-Oct 25
7Oe Bulls: Aug 15-Nov 5 737,739-741
7Pa Bulls: Aug 15-Sep 20 719-722,731
 Bulls: Oct 15-Oct 31 719-722,731
7Pb Bulls: Aug 15-Sep 20 732-735,744-746
 Calves: Oct 4-Oct 11 732-734,744-745
7Pc Bulls: Aug 15-Sep 20 736,743
 Bulls: Oct 15-Oct 31 736,743
 Bulls: Aug 15-Sep 20 742,757-758
 Bulls: Aug 15-Oct 31 750
7Pd Bulls: Aug 15-Oct 31 751-754
7Pe Bulls: Aug 15-Sept 30 747-749,755-756
 Bulls: Oct 15-Oct 31 747-749,755-756

 Limited Entry Hunting

GMZ Class WMU's

5ab Antlerless: 501,502,515
 Bulls: 501,502,515
5c Antlerless: 513
 Bulls: 510,512-514
5d Bulls: 503-506
5e Bulls: 511
6b Bulls: 610,615
6c Bulls: 601-602,604-606,608-609
 Antlerless: 604-606,608-609
 Calf Only: 604-606,608-609
6d Bulls: 607,630
 Antlerless: 607,630
6e n/a
6f n/a
7Oa Antlerless: 701-705,717-718
 Bulls: 701-705,717-718
7Ob Antlerless: 706-713,715
 Bulls: 706-713,715
7Oc Antlerless: 714,716,723-726
 Bulls: 714,716,723-726
7Od Antlerless: 727-730,738
 Bulls: 727-730,738
7Oe Bulls: 739 (Zone E)
7Pa n/a
7Pb Antlerless: 732-735,744-746
7Pc Antlerless: 743
7Pd n/a
7Pe n/a
Table 2. Summary of average moose population and harvest parameters by
Game Management Zone (GMZ) from 1994-96 (1993-95 for GMZ's 7Pa-e).
Post-season density and composition were estimated from population
models.

 Post Post Post % Harvest
 -season -season -season Composition
 Moose/ Bulls/ Calves/
GMZ 1,000 [km.sub.2] Cow Cow Bull: Cow:

5ab 346 0.29 0.50 95 5
5c 206 0.37 0.40 97 3
5d 140 0.30 0.40 99 1
5e 26 0.56 0.40 -- --
6b 88 0.40 0.50 100 0
6c 379 0.35 0.33 73 13
6d 180 0.40 0.30 89 10
6e 172 0.66 0.30 100 0
6f 214 0.65 0.35 100 0
7Oa 308 0.44 0.30 63 22
7Ob 730 0.44 0.40 56 18
7Oc 689 0.49 0.25 65 18
7Od 182 0.31 0.30 70 16
7Oe 148 0.45 0.30 100 0
7Pa 360 2.20 0.27 100 0
7Pb 510 0.30 0.32 67 9
7Pc 566 0.27 0.20 98 1
7Pd 200 0.49 0.25 100 0
7Pe 216 0.58 0.25 100 0
[bar]X 298.0 0.42 0.33
SD 217.8 0.13 0.08

 % Harvest
 Composition Resident Resident Harvest

GMZ Calf DPUA (1) DPK (2) KPUA (3)

5ab 0 766.5 30.0 27.6
5c 0 342.7 26.3 15.3
5d 0 207.9 27.3 8.9
5e -- 0.0 0.0 0.0
6b 0 98.8 20.8 4.8
6c 13 498.4 20.2 28.8
6d 1 71.4 18.1 4.6
6e 0 115.2 20.2 7.7
6f 0 66.2 16.5 6.8
7Oa 15 668.3 33.4 21.5
7Ob 26 1973.8 32.3 66.5
7Oc 17 988.9 27.5 40.0
7Od 14 464.3 27.7 17.4
7Oe 0 101.6 19.8 7.7
7Pa 0 535.2 24.4 22.0
7Pb 24 546.3 14.5 38.0
7Pc 1 517.0 19.7 35.4
7Pd 0 48.1 16.7 4.9
7Pe 0 98.0 16.6 6.4
[bar]X 426.9 22.9 19.2
SD 470.0 5.8 16.9

 % Growth
 Harvest Rate
GMZ (Mh) ([lambda])

5ab 7.3 0.97
5c 6.8 0.99
5d 5.9 1.05
5e 0.0 1.02
6b 5.1 0.91
6c 7.0 0.98
6d 2.5 1.00
6e 4.2 0.93
6f 3.0 0.99
7Oa 6.4 1.00
7Ob 8.2 1.03
7Oc 5.4 0.99
7Od 8.6 0.97
7Oe 4.9 0.96
7Pa 5.7 0.97
7Pb 6.9 1.02
7Pc 5.8 0.90
7Pd 2.4 0.98
7Pe 2.9 0.99
[bar]X 5.2 0.98
SD 2.2 0.04

(1) DPUA = hunting pressure (resident hunter days/1,000 [km.sup.2] of
habitable moose range)

(2) DPK = hunting effort (resident hunter days/moose)

(3) KPUA = harvest density (resident and non-resident kill/1,000
[km.sup.2])


ACKNOWLEDGEMENTS

I thank J. Youds, R. Marshall, S. Sharpe, D. Heard, and J. Elliott for providing moose management data and for technical review of an earlier management report, upon which this paper is based. Special thanks to K. Child, T. Timmermann, and V. Crichton who also conducted a technical review of a revised management report released for stakeholder discussion.

REFERENCES

BERGERUD, A. T. 1992. Rareness as an antipredator strategy to reduce predation risk for moose and caribou. Pages 1008-1021 in D. R. McCullough and R. B. Barrett (eds.) Wildlife 2001: Populations. Elsevier Science Publ. Ltd., London, England.

BOER, A. H. 1992. Fecundity of North American moose (Alces alces): a review. Alces Suppl. 1:1-10.

BOERTJE, R. D., P. VALKENBURG, and M. E. MCNAY. 1996. Increases in moose, caribou, and wolves following wolf control in Alaska. J. Wildl. Manage. 60:474-489.

CHILD, K. N. 1983. Selective harvest of moose in the Omineca: some preliminary results. Alces 19:162-177.

-- and D. A. AITKEN. 1989. Selective harvests, hunters, and moose in central British Columbia. Alces 25:81-97.

CRETE, M. 1987. The impact of sport hunting on North American moose. Swedish Wildl. Res. Suppl. 1:553-563.

--, R. J. TAYLOR, and P. A. JORDAN. 1981. Optimization of moose harvest in southwestern Quebec. J. Wildl. Manage. 45:598-611.

EASTMAN, D. S. and R. RITCEY. 1987. Moose habitat relationships and management in British Columbia. Swedish Wildl. Res. Suppl. 1:101-117.

FRYXELL, J. M., W. E. MERCER, and R. B. GELLATELY. 1988. Population dynamics of Newfoundland moose using cohort analysis. J. Wildl. Manage. 52:14-21.

GASAWAY, W. C., R. J. BOERTJE, D. V. GRANGAARD, D. G. KELLEYHOUSE, R. O. STEPHENSON, and D. G. LARSEN. 1992. The role of predation in limiting moose at low densities in Alaska and Yukon and implications for conservation. Wildl. Monogr. 120.59 pp.

--, D. J. REED, and S. J. HARBO. 1986. Estimating moose population parameters from aerial surveys. Biol. Pap. Univ. Alaska, Fairbanks. No. 22. 108 PP.

HATTER, I. W. 1998. A Bayesian approach to moose population assessment and harvest decisions. Alces 34:47-58.

-- and W. A. BERGERUD. 1991. Moose recruitment, adult mortality and rate of change. Alces 27:65-73.

LARSEN, D. G., D. A. GAUTHIER, and R. L. MARKEL. 1989. Causes and rate of moose mortality in the southwest Yukon. J. Wildl. Manage. 53:548-557.

(MELP) MINISTRY OF ENVIRONMENT, LANDS AND PARKS. 1996. Wildlife harvest strategy--Improving British Columbia's Wildlife Harvest regulations. Wildl. Branch, Min. Environ. Lands and Parks, Victoria, BC. 73 pp.

MUNRO, W and P. S. PETTICREW. 1979. Preliminary moose management plan for British Columbia. Fish and Wildl. Branch, Min. Environ. Lands and Parks, Victoria, BC. 29 pp.

REID, R. 1997. The economic value of resident hunting in British Columbia. 1995. Wildl. Branch, Min. Environ. Lands and Parks, Victoria, BC. 45 pp.

SCHWARTZ, C. C., K. J. HUNDERTMARK, and T. H. SPRAKER. 1992. An evaluation of selective bull moose harvest on the Kenai Peninsula, Alaska. Alces 28:1-13.

SEIP, D. R. 1992. Factors limiting woodland caribou populations and their interrelationships with wolves and moose in southeastern British Columbia. Can. J. Zool. 70:1494-1503.

TIMMERMANN, H. R. and M. E. BUSS. 1998. Population and harvest management. Pages 559-615 in A. W. Franzmann and C. C. Schwartz (eds.). Ecology and management of the North American moose. Smithsonian Inst. Press, Washington, DC.

VAN BALLENBERGHE, V. 1983. The rate of increase in moose populations. Aloes 19:98-117.

-- and J. DART. 1982. Harvest yields from moose populations subject to wolf and bear predation. Alces 18:258-275.

Wildlife Branch, BC Environment, PO Box 9374, Stn. Prov. Gov., Victoria, BC, Canada V8W 9M4
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Date:Jan 1, 1999
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