Sodium, nitrogen, and the interactions between invertebrate and mammalian grazers in a montane meadow

We asked how sodium and nitrogen interact with temperature to affect nest-site and nutrient-limited ants. The key results were that ants preferred warm nests to cool nests, and salty plots to N-enriched plots. But, the ants exhibited the strongest preference for warm nests in salty plots. An unexpected result was that nests in the salty plots were not only, well, saltier, they were also warmer because deer preferentially browsed the vegetation in the sodium-enriched plots. Thus, not only does sodium directly affect nest-site selection and colony performance in ants, it indirectly affects them by altering the foraging behavior of deer.