P.O. Box 230

McGrath, AK  99627

PHONE: (907) 524-3323

FAX: (907)524-3324        




To:  David James, Regional Supervisor                                     November 2, 2001


Through:  Roy Nowlin, Management Coordinator


From:  Toby Boudreau, McGrath Area Biologist

            Mark Keech, Wildlife Research Biologist

            Jay Ver Hoef, Biometrician

            Patrick Valkenburg, Research Coordinator


Subject:  2001 Estimates of Moose Numbers in the Proposed GMU 19D Experimental Micro Management Area (EMMA), Unit 19D East, and the Candle-Wilson Trend Area



The department has been working with the Governor’s appointed Adaptive Wildlife Management Team to reverse a decline in moose harvest by local residents of Subunit 19D. Information from local hunters and moose trend area counts within GMU 19D indicated declines in the moose population during several bad winters from 1989–1993. Density estimates during spring 1996 and 1999, and during fall 2000, indicated low moose densities in the general area. As a potential solution to insufficient moose harvests in the McGrath area, the Adaptive Wildlife Management Team identified a 520 mi2 area that would be considered for intensive management (EMMA).


In response to the need for more accurate and consistent data on moose numbers in GMU 19D East, the need for more intensive surveys in the proposed EMMA, and the need to quantify sightability of moose, we conducted intensive moose surveys from 23 October to 1 November 2001. This expanded information was collected to enable the department to develop a management plan that is biologically sound, is aligned with recommendations of the Governor’s team, and meets the needs of local residents.


Survey Goals

1)      Obtain an accurate estimate of moose numbers in the proposed EMMA (520 mi2).

2)      Corroborate the estimate of moose numbers in GMU 19D East (5200 mi2) obtained in fall 2000.

3)      Estimate sightability of moose in habitats found in GMU 19D East.

4)      Survey the Candle-Wilson trend area to compare with previous data.




We used up to five aircraft, including one aircraft for daily tracking of radiocollared moose. Three of the aircraft were Super Cubs, one was a Bellanca Scout, and one was a PA-12 Super Cruiser. Pilots for the survey were Troy Cambier, Paul Zaczkowski, Mike Litzen, Jim Ellis and Patrick Valkenburg. Observers were Shelly Szepanski, Tony Hollis, Jay Ver Hoef, Mark Keech, and Toby Boudreau. Department of Public Safety, Division of Fish and Wildlife Protection provided their pickup truck to facilitate fueling of the ski-equipped aircraft.


We began the survey by counting all possible sample units in the EMMA (87 units out of 860 in GMU 19D East). Sample units were 2 minutes of latitude (2 miles) from north to south by 5 minutes of longitude (about 2.5–3 miles) east to west. Sample units in the EMMA and in adjacent GMU 19D East were searched at an intensity of 4–9 minutes per mi2 depending on vegetation type. More forested units were searched at the higher intensities. Additionally, collared moose observed within sample units were recorded for sightability calculations. After counting all units in the EMMA, we randomly selected and counted 131 units in the remainder of GMU 19D East (out of 773 possible units). Finally, Toby Boudreau counted the Candle-Wilson trend area with the same pilot and at the same intensity as in previous years. Flying conditions during the survey were good, with light winds, good visibility, and generally light overcasts.



We observed 440 moose during the complete census of the proposed EMMA and 302 moose in units sampled outside the EMMA in GMU 19D East. We calculated an estimate of 1863 moose in GMU 19D East (including the EMMA) (Table 1). Results of the 2000 and 2001 fall surveys, and results of counts in the Candle-Wilson trend area are presented below (Tables 1 and 2).


Table 1. Results of moose surveys within the proposed EMMA and Unit 19D East during fall 2000 and 2001. Confidence intervals are 95%.




Area (mi2)

Population estimate

Calves:100 Cows

Bulls:100 Cows

Yearling bulls:100 cows


19D East (5,200)

869 ±290

22 ± 13

44 ± 27

20 ± 15


19D East (5,200)

1863 ± 485

29 ± 14

37 ± 18

9 ± 5


EMMA (520)

440 ± 0

34 ± 0

18 ± 0

8 ± 0



Table 2  Results of moose surveys within the Candle-Wilson trend count area, 1989–2001



Bulls:100 Cows (N)

Yearling bulls:100 Cows (N)

Calves:100 Cows (N)

Total moose counted


18 (20)

6 (6)

47 (52)



26 (29)

4 (4)

24 (27)



20 (13)

0 (0)

31 (21)



9 (8)

3 (2)

27 (25)



26 (15)

14 (8)

39 (23)



20 (25)

4 (5)

17 (22)






no survey


18 (15)

7 (6)

34 (29)



13 (10)

6 (5)

52 (41)



13 (7)

8 (4)

38 (21)






no survey


9 (5)

4 (2)

29 (16)



6 (4)

2 (1)

22 (14)



During surveys within the proposed EMMA, 32 of 38 (84%) collared moose known to be within sample units were observed. When applied to the 2001 data, the estimated moose population within the EMMA becomes 531 (95% CI 453–609) and the estimate for GMU 19D East is 2247 (95% CI 1570–2924).



Based on moose survey data collected in GMU 19D East since 1996, no clear trend in moose numbers is apparent. However, the bull:cow ratio in the proposed EMMA is low, particularly in the western portion (Candle-Wilson trend count area) and has declined since the early 1990s. The low bull:cow ratio in this area results from an imbalance between hunting and recruitment. The bull:cow ratio in the remainder of GMU 19D East remains relatively high.


There are presently an estimated 530 moose in the proposed EMMA (census corrected for sightability) or about 1 moose/mi2, and it appears that moose in the proposed EMMA may be increasing (judging from yearling bull:cow and calf:cow ratios). The current estimate of moose population size in the proposed EMMA helps explain why body condition indices of moose in this area are intermediate between high-density areas (e.g., GMU 20A) and low-density areas (e.g., Denali and Yukon Flats). The 2000 survey of GMU 19D East apparently resulted in a low estimate of moose numbers because of inadequate sampling intensity and poor sightability due to mediocre survey conditions.