Do bighorn sheep use desert tortoise burrow spoil piles as mineral licks in southern California?

Bulletin, Southern California Academy of Sciences
Bureau of Land Management, Coachella Valley Conservation Commission
By: , and 

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Abstract

In a previous study, bighorn sheep (Ovis canadensis) were periodically photographed by trail cameras when they visited desert tortoise (Gopherus agassizii) burrows in the San Bernardino Mountains near Palm Springs, California, USA. The authors suggested that bighorn sheep may utilize the excavated spoil material from burrows as a mineral lick. To test that supposition, we collected soil samples from the spoil piles and undisturbed surface soil up to 1 m away at two desert tortoise study sites with bighorn sheep at the aforementioned site and another nearby site. We hypothesized that sodium concentrations would be greater in spoil than in nearby surface soil samples. Common major cations were quantified in soil samples using inductively coupled plasma-mass spectrometry following microwave-assisted digestion to solubilize the fraction of elements that could become biologically or environmentally available. Mean sodium concentrations were greater in burrow spoil samples than in undisturbed soil samples at both sites, likely due to aqueous leaching of sodium from surface to subsurface soil horizons. Although we did not collect evidence of geophagy by bighorn sheep, the behavior is well known. However, trail camera photographs of bighorn sheep with their head next to the entrance of tortoise burrows suggests that they may periodically utilize sodium and other elements brought to the surface by desert tortoises that are otherwise unavailable to bighorn sheep on the surface.

Publication type Article
Publication Subtype Journal Article
Title Do bighorn sheep use desert tortoise burrow spoil piles as mineral licks in southern California?
Series title Bulletin, Southern California Academy of Sciences
DOI 10.3160/0038-3872-124.2.55
Volume 124
Issue 2
Year Published 2025
Language English
Publisher Southern California Academy of Sciences
Contributing office(s) Columbia Environmental Research Center, Southwest Biological Science Center
Description 12 p.
First page 55
Last page 66
Country United States
State California
City Palm Springss
Other Geospatial San Bernardino Mountains
Additional publication details