"In North America there is one large animal that belongs almost entirely to the realm of towering rock and unmelting snow. Pressing hard against the upper limit of life's possibilities, it exists higher and steeper throughout the year than any other big beast on the continent. It is possibly the best and most complete mountaineer that ever existed on any continent. Oreamnos americanus is its scientific name. Its common name is mountain goat." -Douglas H. Chadwick
By :: Karen Loveless, Regional Biologest, Montana FW&P
The Rocky Mountain Goat Alliance sponsored their 2nd annual volunteer mountain goat survey in the Crazy Mountains of Montana over the weekend of August 6-7, 2016. A total of 28 volunteers backpacked into the Crazy Mountains in 14 different teams in order to count and classify mountain goats. Volunteers recorded locations and group composition for goats observed during their backcountry trip. Each team camped in an assigned area, so that volunteers were distributed throughout mountain goat range in the Crazy Mountains. The objective of the survey was to classify a representative sample of the population in order to estimate kid production.
The result of this effort was 223 observations of mountain goats. After examining locations and timing of observations, some of these goat observations were not included in the final results due to likely duplicate observations of the same goats by neighboring teams. After discarding likely duplicates, the final tally was: 163 classified goats including 119 adults, 16 yearlings, and 28 kids. This resulted in a ratio of 24 kids per 100 adults, or 21 kids per 100 “older goats” (including both adults and yearlings). Some volunteers were able to get close enough to classify adult goats as nannies or billies, resulting in a total of 12 billies, 11 nannies, and 96 unclassified adults.
This year’s kid ratios were much lower than those observed during the 2015 survey, which resulted in 54 kids per 100 adults, and 47 kids per 100 older goats. The ratios of yearlings to adults were more similar, with 13 yearlings per 100 adults observed in 2016, and 16 yearlings per 100 adults in 2015.
The much lower ratios of kids observed in 2016 as compared to 2015 were potentially concerning, however the ground survey methods had only been minimally tested and we weren’t certain how closely the survey results represented actual kid ratios in the population. Fortunately, an aerial survey had been planned for this year also, and we were able to complete the survey one week after the ground survey.
Results of the aerial survey were very similar to the results of the ground survey, with 22 kids per 100 adults, 19 kids per 100 older goats, and 12 yearlings per 100 adults. This year’s recruitment is lower than average, but within the range of what we’ve observed previously; the long-term average recruitment for this district is 27 kids per 100 older goats, and since 1989 we’ve observed ratios ranging between 18 – 37 kids per 100 older goats. If low recruitment continues for multiple years, this can have impacts on the population dynamics, however one year of below average recruitment is not cause for concern. It will be important to continue monitoring this trend.
In summary, the results of 21 kids per 100 older goats documented by the volunteer ground survey was slightly higher but very similar to the 19 kids per 100 older goats observed during the aerial survey. Since we did not conduct an aerial survey in 2015, we don’t know how similar the 2015 ground versus aerial survey results would have been. The 2015 results of 47 kids per 100 older goats were very high; we have never documented recruitment higher than 37 kids per 100 older goats in this district.
Regardless, the ground survey in 2015 was useful in that it documented high reproduction, and the 2016 survey documented that reproduction was much lower this year. It will be useful to continue comparing results of these two survey methods, if feasible, in future years, and further refine the ground survey as a tool for tracking recruitment when aerial surveys are not feasible.
A big thanks to all the volunteers for braving the elements and literally climbing mountains to count goats! I was impressed with everyone’s efforts, and really appreciate the detailed notes and maps. A big thanks as well to Pete Muennich of the Rocky Mountain Goat Alliance for recruiting and organizing volunteers. Great job everyone! I hope it was a fun and worthwhile experience.