Referee 1's Review:

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N.B. These are the comments made by the referee when reviewing an earlier version of this paper. Prior to publication the manuscript has been revised in light of these comments and to address other editorial requirements.
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This manuscript provides new data suggesting that, in bats, the function of visiting mineral licks is primarily for detoxification of plant secondary metabolites, rather than, or in addition to, mineral supplementation. The manuscript is interesting, well written and succinct and the methods/sample sizes are appropriate. However, as outlined below, some clarifications/additions are needed in various sections.

Specific comments
Abstract, penultimate conclusion sentence. Reproduction is mentioned here, but not introduced near the beginning of the Abstract.

P5, L12: fruit-eating Artibeus. This statement requires a reference.

P5, L1 methods: Add country.

Methods: Bats can fly. How far were control sites from mineral licks and how likely or unlikely was it that control site bats also visited the licks? Please clarify.

Discussion: Is it possible that absorption of minerals from fruit or insects differs? Please discuss briefly.

Figure legend or Figure 1. To help the reader, restate either in the legend or directly in the figure that the Carollia controls were the ones on insect-rich diets. You may have mentioned this, but it is interesting that the nitrogen isotope ratio of both Artibeus groups was similar to the Carollia at the mineral licks.