A natural salt lick is a location where wild animals instinctively gather to consume mineral salts and trace elements directly from exposed soil, rock formations, or mineral-rich water. These sites represent concentrated sources of nutrients that are often sparse in the surrounding environment. The practice, known as geophagy when soil is consumed, is a survival behavior for many species across diverse ecosystems. These geological features serve as gathering points for wildlife populations.
Geological Origins and Formation
The development of a natural salt lick is a slow geological process driven by the movement of water through the Earth’s crust. These formations typically begin with underlying bedrock, containing ancient mineral deposits. Water acts as a solvent, percolating through the rock layers and dissolving soluble compounds such as halite, the mineral form of sodium chloride. As this mineral-rich groundwater rises toward the surface, it encounters conditions that cause the water to evaporate, such as exposed cliffs, dry riverbeds, or areas near salt springs. The evaporation leaves behind a concentrated residue of salts and minerals on the soil or rock surface.
Essential Nutritional Needs
Animals, particularly herbivores, seek out salt licks to correct nutritional imbalances common in plant-based diets. While plants provide bulk energy and protein, they are low in sodium and certain trace minerals. This deficiency is exacerbated when spring and summer forage is high in potassium, which interferes with the body’s ability to retain sodium. Sodium is necessary for maintaining proper nerve function, muscle contraction, and regulating body fluid balance. Other minerals acquired at these sites, including calcium and phosphorus, are necessary for structural growth and the rapid development of antlers in male deer and elk.
Wildlife Behavior and Seasonal Use
Visits to natural licks are dependent on the reproductive and physiological cycles of the animals. Use generally peaks in the spring and early summer, coinciding with the period of greatest mineral demand for females nursing young and for males undergoing rapid antler growth. Behavior at these sites often involves licking the exposed soil, rock, or mineral crust, a practice that can wear down the substrate over time, sometimes resulting in deep pits or overhangs known as “hedging.” The licks function as social gathering points, where species like deer, moose, and mountain goats congregate, though this concentrated activity also presents an opportunity for predators. Activity is generally greatest during the crepuscular hours of dawn and dusk.
Natural Versus Man-Made Licks
Naturally occurring salt licks are chemically complex, often containing a broad spectrum of trace elements that are balanced by nature. Mined salt rock, for instance, can contain over 60 different minerals, many of which are chelated, meaning they are naturally bound to organic nutrients and are highly bioavailable for animal absorption.
Man-Made Licks
In contrast, man-made licks, such as commercial mineral blocks, are typically manufactured with a heavier concentration of sodium chloride. While they often include added calcium, phosphorus, and vitamins, they may lack the full diversity of trace elements found in natural deposits. Artificial licks are sometimes introduced by humans to attract wildlife for observation or hunting, or they may be used by wildlife managers to deliver specific nutrients or medications to a population.