Moose (Alces Alces) Population Size and Density in the Inuvik Region of the Northwest Territories, Canada

13 th Arctic Ungulate Conference Yellowknife, Canada 2226 August, 2011

Brief Communication

Moose (Alces alces) population size and density in the Inuvik Region of the Northwest Territories, Canada

Tracy Davison 1 & Kristen Callaghan 2

1 Government of the Northwest Territories, Environment and Natural Resources, P.O. Box # 2749, Inuvik, NT, X0E 0T0, Canada (Corresponding author: [email protected]). 2 Gwich’in Renewable Resources Board, P.O. Box 2240, Inuvik, NT, X0E 0T0, Canada.

Abstract: Responding to community concerns, the Gwich’in Renewable Resources Board (GRRB) and the Government of the Northwest Territories Department of Environment and Natural Resources (ENR) conducted an aerial moose (Alces alces) survey in the Inuvik region of the Northwest Territories, Canada to estimate moose density and distribution. e survey was own in March 2011 and a random stratied sample design was used. Local knowledge was incorpo rated in to the stratication of survey cells. Moose density in survey blocks ranged from 9.66 moose/100 km 2 in the Ikhil Pipeline block to 0 in the Peel River block with a coarse overall moose density 2.24 moose/100 km 2. Densities found were low but within expected range for the species in this region of North America based on past surveys.

Key words: Alces alces; moose; Northwest Territories; population; survey.

Rangifer, 33, Special Issue No. 21, 2013: 123–128

Introduction 3.78 moose/100 km 2 (Lambert, 2006). Moose In the Gwich’in Settlement Area (GSA) and in the ISR have not been surveyed since the the adjacent Inuvialuit Settlement Region mid1980’s (Jingfors & Kutny, 1989). Cur (ISR) of the Northwest Territories (NWT), rent local knowledge suggests moose numbers Canada (Fig.1), management of moose (Alces have increased in the Mackenzie Delta (Fig. 1). alces) populations is primarily the responsibil Local barrenground caribou (Rangifer taran- ity of comanagement boards and of the territo dus groenlandicus) herd population numbers rial government. e Gwich’in Renewable Re have been low, in particular the Cape Bathurst sources Board (GRRB) is the comanagement herd, resulting in a harvest closure of that herd board for wildlife in the GSA while the Wild in 2007. So, despite a perception of current life Management Advisory Council (Northwest healthy moose population the declining cari Territories) [WMAC (NWT)] is the coman bou led to community concerns about impacts agement board for wildlife in the ISR. of possible predators and harvesters switching A 2006 survey in GSA reported low and to moose. In response to these concerns and in declining (from past surveys between 1980 order to inform possible management decisions and 2000) moose densities ranging from 0 to by GRRB and WMAC (NWT), we conducted

This journal is published under the terms of the Creative Commons Attribution 3.0 Unported License Rangifer, 33, Special Issue No. 21, 2013 Editor in Chief: Birgitta Åhman, Technical Editor Eva Wiklund and Graphic Design: Bertil Larsson, www.rangifer.no 123 an aerial survey of moose population density input from the RRCs. is includes adjusting and distribution in northwest NWT in March the Arctic Red River survey block (Fig. 1) into 2011. a discontinuous block with a portion near the community of Tsiigehtchic and a portion up Methods river. New survey blocks were created in the Population estimates followed the stratied ISR. Cells were randomly selected for survey random sampling methods of Gasaway et al., ing, with 2% of cell selections made manually (1986) and was analyzed using the GeoSpatial to ensure good coverage, such as the inclusion Population Estimator Software (Delong, 2006). of both high and low survey blocks. Surveyed Density estimates (moose/100 km 2) were calcu cells represented 4,368 km 2 and 16.1 % of all lated for each of the eight survey blocks based survey blocks (Table 1). on total number of moose sighted in selected We ew the survey in March 2011 using a cells (# moose/area surveyed * 100). Cessna 206 and Cessna 185 xedwing aircraft. We held workshops with local Renewable Re Surveyed cells were to be covered in their en sources Councils (RRCs) and Hunter and Trap tirely with the intent to detect all moose in the per Committees (HTCs) to dene the survey cell. Search intensity varied by block based on region and map areas of expected high and low block vegetation cover; heavily treed areas were moose density in the survey period. Local ex covered more intensely than open/tundra areas. perts were used as a costeective way to stratify Snow tracks were circled to determine if the the survey area while ensuring the involvement moose was still located in the block. A pilot, of local indigenous people. navigator, and two observers spotted and clas Aerial survey methods generally followed sied moose inside each selected cell and noted those described by Kellie & Delong (2006). e any moose observed outside selected cells. Lo survey region was divided into 2’ latitude by 5’ cations were recorded using GPS. Wolves and longitude (~ 4 km by 4 km) cells using ArcGIS other wildlife observations inside or outside se 9.2 (ESRI, 2006). e cells were then stratied lected cells were also recorded. as high or low moose density using workshop classications and habitat data. If cells were not classied as high or low moose density dur Results & Discussion ing the workshops vegetation cover maps were Survey ights were conducted from March 16 used to classify the cells. Area classied as open 24, 2011 with a total of 61.9 hours own. We deciduous, closed deciduous, shrubs, wet her observed a total of 168 moose: 79 within sur baceous, emergent vegetation were considered veyed grid cells and 89 moose outside surveyed areas were high density of moose would be cells. We classied 63% of observed moose: 40 expected. Areas with closed needle leaf, open cows, 32 calves and 34 bulls, resulting in bull needle leaf, nonvegetated soil, sparse vegeta to cow and calf to cow ratios of 85:100 and tion or rock/gravel were considered low moose 80:100, respectively. Composition estimates density classes. may be biased as the presence of calves aided Eight areas of interest were identied based in classication of cows, such that cows with on past surveys and input from HTCs, RRCs, out calves may have been more often unclas GRRB, and WMAC (NWT) (Fig. 1). Survey sied than by chance. Other wildlife observed blocks in the GSA were similar to the 2006 sur included; moose, 33 sheep, 38 wolves, and ve vey with slight modications to the Peel River caribou. and Arctic Red River survey blocks based on A total area of 3519 km 2 was surveyed

This journal is published under the terms of the Creative Commons Attribution 3.0 Unported License 124 Editor in Chief: Birgitta Åhman, Technical Editor Eva Wiklund and Graphic Design: Bertil Larsson, www.rangifer.no Rangifer, 33, Special Issue No. 21, 2013 Fig. 1. Stratication and surveyed cells in eight survey blocks: 1) Delta North, 2) KugalukMiner Rivers, 3) Ikhil Pipe line, 4) InuvikTsiigehtchic, 5) Mackenzie Gas pipeline route, 6) Richardson Mountains, 7) Peel River, and 8) Arctic Red River.

Delta North 1448.1 15.5 10 61.21 28,19 4.49 NA

Kugaluk- Miner Rivers 1155.9 16.0 2 NA 2 - 1.08 NA

Ikhil Pipeline 671.6 17.0 11 NA 2 - 9.66 NA

Inuvik- Tsiigehtchic 8611.5 16.0 27 170.88 43.30 1.94 1.62 Mackenzie Gas Pipeline 1286.2 16.5 7 41.47 28.40 3.33 2.31 Route

Richardson Mountains 5705.6 15.8 20 126.24 64.68 2.23 3.54

Peel River 704.1 17.0 0 - - 0.00 0.84 Arctic Red River 2196.3 17.2 2 12.19 7.70 0.53 0.00

1 Standard Error. 2 Could not compute estimate – insucient samples in one stratum. making the coarse overall moose density 2.24 3.33 moose/100 km 2 in the Mackenzie Gas moose/100 km 2. e highest density, 9.66 Pipeline Route, and 2.23 moose/100 km 2 in moose/100 km 2, was found in the Ikhil Pipe the Richardson Mountains (Table 1). line survey block (Table 1). e Arctic Red A sightability correction was not deter River block was found to have very low densi mined for our survey. Moose sightability varies ties with 0.53 moose/100 km 2. No moose were by season, snow cover, habitat, and size of the observed in the Peel River block; however we survey unit (Gasaway et al. , 1986). Habitat in do not believe there are no moose in the area, the study region ranged from alpine/tundra to as there were tracks observed. e Peel River semiopen coniferous forest with sightability block was the smallest survey area and we be higher in more open habitats. It is possible to lieve that the sample size was too small to detect estimate a sightability correction factor using moose at the low densities they occur in this radiocollared moose (Gasaway et al., 1986). area. e densities found in the other blocks However, since there were no collared moose were: 4.49 moose/100 km 2 in Delta North, in our study area we could not obtain a correc 1.08 moose/100 km 2 in KugalukMiner Rivers, tion factor. 1.94 moose/100 km 2 in InuvikTsiigehtchic, e Delta North and Ikhil Pipeline sur

This journal is published under the terms of the Creative Commons Attribution 3.0 Unported License 126 Editor in Chief: Birgitta Åhman, Technical Editor Eva Wiklund and Graphic Design: Bertil Larsson, www.rangifer.no Rangifer, 33, Special Issue No. 21, 2013 vey blocks had not been previously surveyed. members and harvesters in the stratication of e KugalukMiner river area was surveyed in survey areas was important to improve accura 1988, with an overall density of 6 moose/100 cy of population estimates. Natural low densi km 2 (Jingfors & Kutny, 1989) which is higher ties make it dicult to detect trends between than the density found in this survey (1.08 surveys. Composition estimates could be im moose/100 km 2). It is not known if this is a real proved if surveys were conducted before moose trend because we only have two data points that bulls shed their antlers. We advocate that in were obtained using dierent survey methods. formation on moose habitat, recruitment, and e survey block area in 2011 was not as large mortality, as well as increased coverage of fu as the 1988 survey. Compared to the 2006 sur ture surveys would help to increase precision vey in the GSA, the Richardson Mountains and and condence of estimates and would help to Peel River blocks were found to have lower den explain changes in moose distribution, density sities in 2011. e densities for the Richardson and number. Mountain block were also lower than a 2000 helicopter survey of the Richardson Mountains Acknowledgements that included the Yukon where a density of 4.8 Funding was provided by GRRB, ENR, and moose/100 km 2 was found (Yukon Govern by the Northwest Territories Cumulative Im ment, unpublished data). Methods for the 2000 pact Monitoring Program. Many thanks to the survey were quite dierent, as optimal habitat Gwich’in RRCs and Inuvialuit HTCs, to work was own instead of randomly sampling areas. shop participants and to Kevin Allen, Douglas e InuvikTsiigehtchic, Mackenzie Gas Pipe Esagok, Allen Firth, Cheryl Greenland, Samuel line route, and Arctic Red River survey blocks McLeod, George Niditchi, Elvis Raddi, and had higher densities in 2011 compared to the Steven Tetlichi for their keen eyes and patience 2006 survey (Table 1). in the air. Moose in the ISR and GSA are at the north ern edge of their range. As such, environmen References tal factors and range conditions may partially Clu, H.D. 2005. Survey of Moose Abundance explain observed lower densities than in other in the Boreal Forest Around Yellowknife, North- portions of the species’ range. Observed densi west Territories. Final Report to the West Ki ties appear generally consistent with those re tikmeot/Slave Study Society, Yellowknife. ported for other subarctic regions. Franzmann 27pp. http://www.enr.gov.nt.ca/_live/docu & Schwartz (1998) summarized general densi ments/content/WKSS_Moose_Abundance_ ties (moose/100 km2) across the species range Survey_2005.pdf. as < 12 in subarctic areas, 1231 in better rang Delong, R.A. 2006. GeoSpatial Population Es- es, and 40100 in excellent ranges. timator Software User’s Guide. Alaska Depart Densities in the Inuvik Region appear lower ment of Fish and Game, Fairbanks. than other areas of the NWT, except the North Franzmann, A.W. & Schwartz, C.C. (eds.). Slave region where density ranged from 2.0 to 1998. Ecology and Management of the North 3.5 moose/100 km2 in 2005 (Clu, 2005). American Moose. Wildlife Management In e highest densities recorded in the NWT stitute. Smithsonian Institution Press, Wash have been 17 moose/100 km 2 around Fort ington, D.C. 640pp. Good Hope and Norman Wells (Maclean, Gasaway, W.C., DuBois, S.D., Reed, D.J. & 1994; Veitch et al., 1995). Harbo, S.J. 1986. Estimating moose popula Participation of knowledgeable community tion parameters from aerial surveys. — Biol.

This journal is published under the terms of the Creative Commons Attribution 3.0 Unported License 128 Editor in Chief: Birgitta Åhman, Technical Editor Eva Wiklund and Graphic Design: Bertil Larsson, www.rangifer.no Rangifer, 33, Special Issue No. 21, 2013