Salt-seeking behaviour of mammals and ants in a low-sodium Australian alpine environment

Abstract

Salt is an essential nutrient that is found in low concentrations in alpine areas. Salt is thought to be sought by animals through a variety of behaviours including chewing wood, using salt licks, digging and eating plants with high sodium concentrations. We conducted three experiments to investigate whether animals in a low-sodium Australian alpine environment would show a preference for sodium chloride over other salts. Our experiments tested whether 1) alpine mammals would chew on sodium chloride–soaked wooden stakes, 2) ants would be attracted to salt grains and 3) the sodium concentrations in alpine plants are lower compared to plants in other Australian environments. We found that herbivorous mammals, such as rabbits, chewed a greater number of wooden stakes treated with sodium chloride than those treated with other salt solutions. No significant preference was recorded by ants for salt or sugar. Lastly, we found sodium concentration of vegetation decreases with increasing elevations, but the relationship was not statistically significant. Our study was conducted at three locations at elevations of 920 m, 1,200 m, and 1,860 m within Kosciuszko National Park in the Snowy Mountains, New South Wales, Australia.