The Role of Experience in the Visual and Non-Visual Prey Recognition of Fire Salamander Populations from Caves and Streams

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Review of the manuscript “The role of experience in the visual and non-visual prey recognition of fire salamander populations from caves and streams” by Hoover, Manenti and Melotto.

 This manuscript investigates how the larvae of the fire salamander, Salamandra salamandra, change their prey recognition behaviour in relation to different prey stimuli: visual and/or chemical.

The manuscript is clear and relatively well written, and all the starting questions seem correctly addressed by the authors. Methods are sufficiently described, and the sample size (N = 52) appears adequate for experimentally testing.

I commend the authors for using a control condition (i.e., no real prey but an odourless prey replica) in their experimental framework. However, they never use the word “control” in the manuscript. I suggest that the authors describe that condition as “control”, or that at least explain their different choice to the reader.

I have a minor concern about the statistical approach. The authors state to have used in their statistical analyses generalized linear models (GLM). However, the individual identity was used as random factor and therefore this should be a GLMM. The authors should clearly explain their statistical approach to allow a better understanding of their results, and justify the use of GLMs.

In general, tables and figures are appropriate, informative, and well designed. However, Figure 1 needs some slight modification. In fact, the description of the different testing conditions (lines 158-170) does not correspond to the left-to-right ordering in Figure 1: conditions C and D appear inverted inside the Figure. This could create some confusion in the reader, and I suggest that this inconsistency should be fixed by inserting letters corresponding to the test conditions in Figure 1.

In the Discussion, I suggest concentrating on amphibians living in freshwater habitats and in particular on their larvae, rather than citing terrestrial adults that behave as predators in a very different environment. In particular, the example reported in lines 275-280 on Plethodon jordani has little connection with the experimental framework used in the manuscript and should be deleted.

Finally, the format of the References is not consistent with Diversity standards and should be completely revised and corrected accordingly.

I also made several comments directly on the pdf version of the manuscript to better explain my suggestions and recommendations.

 Overall, my personal opinion on this manuscript is positive and I suggest that after a minor revision it should be accepted for publication on Diversity.

 

 

 

 

Comments for author File: Comments.pdf

Author Response

Reviewer 1

 

Review of the manuscript “The role of experience in the visual and non-visual prey recognition of fire salamander populations from caves and streams” by Hoover, Manenti and Melotto.

 This manuscript investigates how the larvae of the fire salamander, Salamandra salamandra, change their prey recognition behaviour in relation to different prey stimuli: visual and/or chemical.

The manuscript is clear and relatively well written, and all the starting questions seem correctly addressed by the authors. Methods are sufficiently described, and the sample size (N = 52) appears adequate for experimentally testing.

 

We thank the reviewer for the positive comments and the useful suggestions. We followed them all.

 

I commend the authors for using a control condition (i.e., no real prey but an odourless prey replica) in their experimental framework. However, they never use the word “control” in the manuscript. I suggest that the authors describe that condition as “control”, or that at least explain their different choice to the reader.

 

We added the use of control condition spelling in the text.

 

I have a minor concern about the statistical approach. The authors state to have used in their statistical analyses generalized linear models (GLM). However, the individual identity was used as random factor and therefore this should be a GLMM. The authors should clearly explain their statistical approach to allow a better understanding of their results, and justify the use of GLMs.

 

We are sorry it was an error of spelling. Yes we used GLMMs. We improved the text.

 

In general, tables and figures are appropriate, informative, and well designed. However, Figure 1 needs some slight modification. In fact, the description of the different testing conditions (lines 158-170) does not correspond to the left-to-right ordering in Figure 1: conditions C and D appear inverted inside the Figure. This could create some confusion in the reader, and I suggest that this inconsistency should be fixed by inserting letters corresponding to the test conditions in Figure 1.

 

We followed the suggestion and we modified the figure 1

In the Discussion, I suggest concentrating on amphibians living in freshwater habitats and in particular on their larvae, rather than citing terrestrial adults that behave as predators in a very different environment. In particular, the example reported in lines 275-280 on Plethodon jordani has little connection with the experimental framework used in the manuscript and should be deleted.

 

Following the suggestion we deleted the example.

Finally, the format of the References is not consistent with Diversity standards and should be completely revised and corrected accordingly.

 

We are sorry we used the endnote style of MDPI. But effectively some journals were not abbreviated and there were many mistakes. We hope that now it is better.

I also made several comments directly on the pdf version of the manuscript to better explain my suggestions and recommendations.

 Overall, my personal opinion on this manuscript is positive and I suggest that after a minor revision it should be accepted for publication on Diversity.

 

 

We are very grateful for the useful suggestions in the attached pdf. We used them all.

Reviewer 2 Report

Comments and Suggestions for Authors

The study investigates the foraging behaviour of fire salamander larvae. Authors performed an experimental approach during which they measured the time spent by larvae to reach preys by controlling visual and olfactive stimuli, before and after a conditioning period in rearing, consisting to fed with both visual and olfactory stimuli.

They showed that larvae were more efficient before conditioning when both cues occurred together. Then, they showed that after conditioning, scores improved with visual stimuli but not with chemical stimuli alone.

 

The MS presents interesting data. I made some suggestions directly on the proof. I feel that the setup lacks sometimes of precision and the Results section especially can be made more flowing. The discussion ends by opening the question about the plasticity of foraging in changing environments but the link with the present work is touch on and I stay left hungry for more.

Comments for author File: Comments.pdf

Author Response

The study investigates the foraging behaviour of fire salamander larvae. Authors performed an experimental approach during which they measured the time spent by larvae to reach preys by controlling visual and olfactive stimuli, before and after a conditioning period in rearing, consisting to fed with both visual and olfactory stimuli.

They showed that larvae were more efficient before conditioning when both cues occurred together. Then, they showed that after conditioning, scores improved with visual stimuli but not with chemical stimuli alone.

The MS presents interesting data. I made some suggestions directly on the proof. I feel that the setup lacks sometimes of precision and the Results section especially can be made more flowing. The discussion ends by opening the question about the plasticity of foraging in changing environments but the link with the present work is touch on and I stay left hungry for more.

 

We thank the reviewer for the very useful comments on the pdf. We changed the text according to all of them. Here we report answers just to the main ones.

 

We thank for underlying the contradiction between what we state, results of the analysis showed in Table 1 and those reported in Table 2. In the analysis is considered also the random effect that is not accounted in Table 2. The stating that visual cues after rearing reduced more time of approach then chemical cues is based mainly on the opposite sign of the interaction and on the fact in tests with visual cues time of approach was strongly lower than in the beginning. However, it is true that reduction occurred also when only chemical cues occur. Thanks to the comments of the reviewer, we are now more cautious, just reporting the facts of the opposite sign of the interactions and the different magnitude in the reduction of the time of approach.