Mineral concentrations and ungulate resource use at Mt. Blue Sky, Colorado, USA
Data files
Jun 26, 2026 version files 129.91 KB
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MtBlueSky_ResourceUse_2023.csv
48.33 KB
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README.md
11.23 KB
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Soil_report_data.csv
28.02 KB
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Surface_sampling_results_from_MSU.csv
42.33 KB
Abstract
This study examines factors that attract bighorn sheep and mountain goats to visitor-use areas at Mt. Blue Sky, Colorado, USA. Ungulates in this high-altitude environment frequently congregate in visitor-use areas, likely in search of minerals. To investigate this behavior, we measured mineral concentrations on surfaces and in soils within visitor-use areas and at control sites in natural areas. Additionally, we conducted behavioral observations to quantify the proportion of time bighorn sheep and mountain goats spent licking various anthropogenic features. Our findings highlight the potential influence of human infrastructure on wildlife resource use and underscore the role of mineral availability in shaping ungulate behavior.
https://doi.org/10.5061/dryad.x95x69pw2
Description of the data and file structure
At Mt. Blue Sky, we collected surface and soil samples to assess mineral concentrations in visitor-use areas. We also recorded ungulate behavior in these areas, specifically the proportion of time mountain goats and bighorn sheep spent licking certain surfaces. We analyzed mineral concentrations using linear regressions in R to assess which surfaces had the highest concentrations of certain minerals. We then correlated these mineral concentrations to the proportion of time animals spent licking certain surfaces.
Files and variables
File: Surface_sampling_results_from_MSU.csv
Description: Surface mineral concentration results from the lab at Metro State University
Variables
- StudyArea: The broader area at Mt. Blue Sky where the samples were taken
- SampleLocation: Specific location at either Summit Lake or the mountain summit where samples were taken
- Month: Month in which sample was taken
- Year: Year in which sample was taken
- Sample Id: Unique sample number
- Na23_mgL: Sodium concentrations in mg/L (milligrams per liter)
- Mg1-26_mgL: Magnesium concentrations in mg/L (milligrams per liter)
- S34_mgL: Sulfur concentrations in mg/L (milligrams per liter)
- Cl35_mgL: Chloride concentrations in mg/L (milligrams per liter)
- K39_mgL: Potassium concentrations in mg/L (milligrams per liter)
- Ca43_mgL: Calcium concentrations in mg/L (milligrams per liter)
- Se82_mgL: Selenium concentrations in mg/L (milligrams per liter)
File: Soil_report_data.csv
Description: Soil mineral concentration results from the lab at Colorado State University
Variables
- Sample_Num: Unique sample number
- Sample_Title: Unique ID, combination of habitat type with a number
- Sample_Title2: Simplified version of Sample_Title for creating figures. "- 2" removed for Chicago Lakes and Parking location names. Still includes Unique ID, combination of habitat type with a number
- Easting: X location for the soil sample
- Northing: Y location for the soil sample
- Julian_date: Julian date for the soil sample
- Date_Collected: Gregorian date for the soil sample
- Magnesium_(mg/Kg) _MDL: Minimum detectable level for magnesium concentration in milligrams per kilogram
- Selenium_(mg/Kg)_MDL: Minimum detectable level for selenium concentration in milligrams per kilogram
- Sodium_(mg/Kg)_ MDL: Minimum detectable level for sodium concentration in milligrams per kilogram
- Chloride_(mg/L)_MDL: Minimum detectable level for chloride concentration in milligrams per kilogram
- Magnesium_Result: Actual lab reading for magnesium in milligrams per kilogram
- Selenium_Results: Actual lab reading for selenium in milligrams per kilogram
- Sodium_Results: Actual lab reading for sodium in milligrams per kilogram
- Chloride_Results: Actual lab reading for chloride in milligrams per kilogram
- Mag_YN: Was the magnesium above the lab's detectable threshold? 0= No, 1= Yes
- Sel_YN: Was the selenium above the lab's detectable threshold? 0= No, 1= Yes
- Sod_YN: Was the sodium above the lab's detectable threshold? 0= No, 1= Yes
- Chl_YN: Was the chloride above the lab's detectable threshold? 0= No, 1= Yes
- Habitat: Specific locations around Summit Lake where the samples were taken
- Sample_occ: Seasonality, 1 indicates the first sampling date, 2 indicates the second sampling date
- Analysis_occ_30: 1= Sample falls within first sampling date range (within 30 days); 2= Actual second sampling occasion
File: MtBlueSky_ResourceUse_2023.csv
Description: Observations of mountain goat and bighorn sheep activity at various locations across Mt. Blue Sky.
Variables
- Remove: Remove observation from analysis due to observer not following data collection protocol or because data was collected at a location other than Summit Lake or the summit. If "Yes", remove these rows, if blank, keep these rows.
- Lat: Latitude of location where observer stood while collecting data
- Long: Longitude of location where observer stood while collecting data
- Date: Date of observation
- Month: Month of observation
- Start Time: Time at which the observation began
- Species: Focal species of ungulate observed
- Dirt_gravel: Number of scans during which primary behavior of focal animal was foraging or licking dirt or gravel in a parking lot, trail or other high-human use area (not including roads). Zeroes and blanks in the data for scans represent no observations.
- Vehicles: Number of scans during which primary behavior of focal animal was licking a vehicle. Zeroes and blanks in the data for scans represent no observations.
- Boulders_bench: Number of scans during which primary behavior of focal animal was licking a bench or boulder in parking lot or other high-human use area (does not include boulders in natural areas); also includes observations of ungulates licking the overlook. Zeroes and blanks in the data for scans represent no observations.
- Road: Number of scans during which primary behavior of focal animal was foraging or licking the surface of a road. Zeroes and blanks in the data for scans represent no observations.
- Restrooms: Number of scans during which primary behavior of focal animal was licking one of the 3 restroom buildings (2 at Summit Lake, 1 at summit). Zeroes and blanks in the data for scans represent no observations.
- Windshelter: Number of scans during which primary behavior of focal animal was licking the windshelter building at Summit Lake. Zeroes and blanks in the data for scans represent no observations.
- Shed: Number of scans during which primary behavior of focal animal was licking the ruins of the summit shed building at the summit. Zeroes and blanks in the data for scans represent no observations.
- Other_buildings: Number of scans during which primary behavior of focal animal was licking any building other than the restrooms, windshelter, or summit shed. Some structures that are included in this category are the Crest House and the overlook wall. Zeroes and blanks in the data for scans represent no observations.
- Nat-area_5ft: Number of scans during which primary behavior of focal animal was foraging or licking anything in a natural area (ex. dirt, rock, vegetation) while 0-5 ft from a road or parking lot. Zeroes and blanks in the data for scans represent no observations.
- Nat-area_5.30ft: Number of scans during which primary behavior of focal animal was foraging or licking anything in a natural area (ex. dirt, rock, vegetation) while 5-30 ft from a road or parking lot. Zeroes and blanks in the data for scans represent no observations.
- Nat-area_30ft: Number of scans during which primary behavior of focal animal was foraging or licking anything in a natural area (ex. dirt, rock, vegetation) while more than 30 ft from a road or parking lot. Zeroes and blanks in the data for scans represent no observations.
- Vigilant: Number of scans during which primary behavior of focal animal was vigilance (stationary, standing with head held at or above shoulder height. Eyes and ears are focused). Zeroes and blanks in the data for scans represent no observations.
- Resting: Number of scans during which primary behavior of focal animal was lying on the ground in an inactive or relaxed state. Could also be standing in a relaxed state with no signs of vigilance. Zeroes and blanks in the data for scans represent no observations.
- Walk_run: Number of scans during which primary behavior of focal animal was walking or running. Zeroes and blanks in the data for scans represent no observations.
- Agonism: Number of scans during which primary behavior of focal animal was being the initiator or recipient of any negative interactions with another sheep, goat or human: threatening, chasing, displacing, butting, biting, aggressive horn movement, avoiding, withdrawing. Zeroes and blanks in the data for scans represent no observations.
- Afflitiative: Number of scans during which primary behavior of focal animal was being the initiator or recipient of any positive interactions with another sheep or goat: grooming, sniffing, nuzzling, sexual behavior, nursing, playing. Zeroes and blanks in the data for scans represent no observations.
- Not_visible: Number of scans during which the focal animal was not visible. Zeroes and blanks in the data for scans represent no observations.
- Total_scans: Sum of all columns with behavioral data. This column is to check accuracy of data collection and entry. If data was recorded following the protocol and entered correctly this will equal 31.
- Agonism_all: Total instances of agonism recorded during observation (during scans and between scans). This data was only recorded by specific observers. Zeroes and blanks in the data for scans represent no observations.
- Obs: Initials of observer who recorded data
- Group_size: Total number of bighorn sheep or mountain goats present in the group including the focal animal observed
- Lambs_kids: Optional question: Number of individuals present in group estimated to be born in 2023. Zeroes and blanks in the data for scans represent no observations.
- Yearlings: Optional question: Number of individuals present in group estimated to be born in 2022. Zeroes and blanks in the data for scans represent no observations.
- 2yrs: Optional questions: Number of individuals present in group estimated to be born in 2021 or earlier. Zeroes and blanks in the data for scans represent no observations.
- Focal_animal: General description of focal animal
- Loc: Broader area where observations took place (Summit Lake or the mountain summit)
- Loc_description: Description of general location where observation took place (summit or Summit Lake) and any nearby landmarks
- Comments: Any comments recorded on the datasheet
File: Summit-Lake_Surface_Analysis-Dryad.R (Zenodo)
Description: R code analyzing the surface sample data from Summit Lake
File: Mt-Summit_Surface_Analysis-Dryad.R (Zenodo)
Description: R code analyzing the surface sample data from the Mt. Blue Sky summit
File: Summit-Lake_Soils_Analysis-Dryad.R (Zenodo)
Description: R code analyzing the soil data from Summit Lake
File: Mt-Summit-Ungulate-Resource_scans-Dryad.R (Zenodo)
Description: R code analyzing the correlation between ungulate resource use data and mineral concentrations at the Mt. Blue Sky summit
File: Summit-Lake-Ungulate-Resource_scans-Dryad.R (Zenodo)
Description: R code analyzing the correlation between ungulate resource use data and mineral concentrations at Summit Lake
Code/software
R (version 3.3.3) and RStudio (2024.12.0.467)
R Packages:
tidyverse
ggplot2
ggpubr
grid
extrafont
extrafontdb
AICcmodavg
emmeans
lmtest
MuMIn
GGally
stats
Hmisc
Access information
Other publicly accessible locations of the data:
- None
Data was derived from the following sources:
- Data collected in the field
Surface Sample Collection: At Mt Blue Sky, we swabbed surfaces to measure mineral concentrations at six locations that ungulates commonly lick and two locations without anthropogenic features that serve as controls. Four locations were swabbed at the mountain summit in June, July, and August of 2023, including the exterior of restroom buildings, an overlook wall, a storage shed, and boulders more than 100 m from parking lots, trails or roads. The remaining four locations were swabbed at Summit Lake in June, July, and August of 2023, including the exterior of restroom buildings, a wind shelter, vehicles in the parking lot, and boulders more than 100 m from parking lots, trails or roads. We swabbed vehicles only at Summit Lake to avoid pseudo-replication because most visitors who stop at Summit Lake also travel to the summit. Boulders were used as control sites to compare to swabs taken on surfaces in visitor-use areas and could not be swabbed at the mountain summit in June due to deep snowpack. For each location and month, 22 samples (n = 506 total) were taken by swabbing a 4-inch square area of the surface using cotton-filled gauze wetted with distilled water. Samples were tested at Metropolitan State University’s Department of Earth and Atmospheric Science’s analytical lab for concentrations of seven minerals: calcium, chlorine, magnesium, potassium, selenium, sodium, and sulfur.
Soil Sample Collection: Soil samples were collected in 9 locations around the Summit Lake Area from June-September 2021. The locations included 3 control areas without anthropogenic features, the Summit Lake parking lot, parking lot perimeter, downslope edge of the Mt. Blue Sky Scenic Byway road, Chicago Lakes overlook, Summit Lake restroom, and the downslope side of the trail connecting the parking lot to the wind shelter. We selected control sites from areas off-limits to visitors and without human infrastructure 100 to 500 m away from test areas and matched for elevation, slope, standing water, vegetation, and soil. For each location, we established five to ten 1m2 plots whose placement was randomly selected with QGIS. Each soil sample was composed of 20 soil cores combined into a single sample weighing 1 pound. Each location was sampled twice: once in June-July of 2021, and a second time in August-September of 2021. All samples sent to Eurofins TestAmerica to test for magnesium, selenium, sodium, and chloride.
Ungulate Resource Use: We conducted animal behavior focal sampling in anthropogenic areas to measure which anthropogenic sources bighorn sheep and mountain goats lick most frequently. Observers followed individual animals for 10 minutes, recording behavior at 20 second intervals giving 31 scans per focal sample. All observations were conducted at Summit Lake and the summit near parking lots, trails, roads, and buildings.
Analysis: We examined the effects of location, month, and interaction of location and month on mineral concentrations using linear regressions built with the lm function in the stats package of R. We built separate linear models for samples taken at the Mt. Blue Sky summit and Summit Lake. In addition, we separated models for each mineral type, which included calcium, chlorine, magnesium, potassium, sodium, selenium, and sulfur. We assessed the normality of estimates for each mineral’s concentration using the qqnorm function in the stats package and performed a natural log transformation for data that did not follow a normal distribution. For each mineral, we built five competing models that we compared using AICc values from the aictab function in R’s MuMIn package. We considered models to have empirical support if they had a ΔAICc < 4 and averaged models that met this criterion using the model.avg function. For the top model(s), we used the emmeans function (emmeans package) to derive p-values (significant at p < 0.05) for pairwise comparisons of mineral concentrations. We used a similar approach to analyze soil samples, though soil samples were only available for Summit Lake.
To understand the influence of surface mineral concentrations on the proportion of scans where animals were seen licking surfaces, we used Spearman rank correlations in the cor function of R’s stats package.