2019 Status of Ameralik caribou population, South region, West Greenland. Technical Report No. 125

This report presents results from the aerial survey carried out by helicopter in 
early March 2019, for the Ameralik caribou population inhabiting the 
northern portion of the South region in West Greenland. This population was 
last surveyed in March 2012, making new estimates of abundance and density 
necessary. In 2001 and 2006 survey method was strip transect counts. In 2012, 
methods changed to Distance Sampling. The March 2019 helicopter survey 
again used Distance Sampling methods.
For March 2019, the Ameralik caribou population abundance was estimated 
at 19,503 caribou (95% CI: 12,404 – 30,665; CV = 0.219; SE = 4268), with density 
4.2 ± 0.9 caribou/km2 (95% CI: 2.6–6.6). Overall survey coverage was 9.7% 
(truncated data), which is a substantial improvement from the 2.15% coverage 
for 2001 and 2006 strip transect count surveys. Further, it is even improved 
relative to 8.6% coverage of the 2012 Distance Sampling systematic transects.
Despite 18 years of harvest management aimed at controlling caribou 
abundance and density, the March 2019 Ameralik caribou population size is 
large and appears to have increased 67% since 2012. The 2012 and 2019 
surveys were similar in coverage and method. There is little overlap in the 
Confidence Intervals for the 2012 and 2019 population estimates. Further, the 
2019 CV (0.22) indicates good precision in the 2019 population estimate. The 
three combined make it reasonable to assume a trend of increasing population 
size over the 2012-2019 period. 
The density estimate for the Ameralik population was 4.2 caribou per km2 in 
area of survey effort. This value is much greater than the management 
recommended target of 1.2 caribou per km2 (Kingsley & Cuyler 2002, Cuyler 
et al. 2007). At almost four-fold the target density, Xeric Inland’s 5.8 
caribou/km2 may have influenced the observed poor 2019 calf recruitment 
and sex ratio (below). Exceeding the target caribou density is assumed to raise 
the risk of overgrazing and thus decline in caribou abundance.
Relative to the 2006-2012 period, late-winter calf percentage was similar, 
however, calf recruitment declined somewhat from previous values. In 
contrast, the 2019 sex ratio of 22 bulls per 100 cows was poor and considerably 
lower than previous values, i.e., 83, 81, 62 in 2001, 2006, 2012, respectively, for 
animals age > 1-year. Population trend beyond 2019 is uncertain, and there is 
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always the possibility of future catastrophic stochastic events, including 
extreme weather and pathogen outbreaks.
Environmental conditions during the 2019 survey provided extraordinary 
camouflage for caribou. Pooling environmental covariates into a single index 
for camouflage will improve detection function modelling. Skilled observers 
and flying helicopter low and slow were critical factors permitting detection 
of caribou, specifically because 17% of all groups remained stationary. 
Beyond population parameters, results of interest included relatively high 
elevations, mean 647 m, used by the Ameralik caribou population in early 
March. This reflects the relative scarcity of low elevations in the region and 
likely also avoidance of human disturbance in lowlands. Further, and in 
contrast to other caribou populations in West Greenland, most (92%) cows 
possessed antlers in the Ameralik population.