Review History


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Summary

  • The initial submission of this article was received on November 10th, 2016 and was peer-reviewed by 2 reviewers and the Academic Editor.
  • The Academic Editor made their initial decision on December 13th, 2016.
  • The first revision was submitted on January 20th, 2017 and was reviewed by 1 reviewer and the Academic Editor.
  • A further revision was submitted on March 2nd, 2017 and was reviewed by the Academic Editor.
  • A further revision was submitted on March 10th, 2017 and was reviewed by the Academic Editor.
  • The article was Accepted by the Academic Editor on March 11th, 2017.

Version 0.4 (accepted)

· · Academic Editor

Accept

Thank you for making all of the changes I requested.

Version 0.3

· · Academic Editor

Minor Revisions

Thanks for your careful revisions. I have just a few more final changes I'd like you to make, which are indicated in the annotated pdf.

Version 0.2

· · Academic Editor

Major Revisions

The reviewer indicated that there are still some issues with your manuscript. Please revise it again to address this reviewer's concerns.

Reviewer 2 ·

Basic reporting

Authors have considered most of reviewers comments to the first version of the manuscript. They gave explanations of the changes and responses to both reviewer's remarks, yet unfortunately, the numbering of lines they refer to in explanation of changes does not correspond to the ones in the revised manuscript.

I have checked the manuscript, which is improved, including the language. Still, there are some issues that authors should consider and make necessary changes to the text.

It is not clear, why two additional species were included in species richness analyses, and why their distribution was not modelled like for other eight species/taxa. The question is also, why these two additional species, and not any other ones – probably there were more non-troglobiotic taxa in studied caves,. Add explanation in M&M, or make additional analyses.

You tested the importance of distance from cave entrance for your models, and added explanation why you found it uninformative (or not giving any additional information, at least). This is now in discussion part (L. 298-300), but it would fit more the results section. If you do not wish to present these results in the main text, you may consider putting these results in the supplementary material.

L.316-318, L. 323-330: This text is surprising. Here you discuss distance from entrance, right after claiming that distance from cave entrances was excluded from the analyses and why. Be consistent and change the text not to bring in contradictory statements.

L.354-362: There are issues that cannot be mentioned and discussed for the first time in conclusion. I find this issue as such example.

L. 362-364: You are not working with superficial subterranean habitats (seesu Culver & Pipan 2014, Shallow Subterranean Habitats), correct and rephrase.

Here are suggestions to make some sentences or issues clearer:
L. 16: “Seasonality impacts species distributions by altering the presence of individuals in a given place through time.”, L.36-39: “Seasonality plays a major role in species distributions by altering the presence of individuals in a given place at a stated time..”
Anything that affects species distributions has this effect (it changes the presence of individuals). Modify this sentence so that you put forward the distinctiveness of seasonality. Here is a suggestion:
“Seasonality impacts species distributions through seasonal changes of the environmental conditions that affect the presence of individuals at a given place.”
L. 57: »such dynamics« - it is not well understood anymore, dynamics of what (as in two sentences before you talk about suitable microclimatic conditions. Make it clear (dynamics of what?).
L.93-116: All the species/genera you considered for observations are identifiable visually, without the need to take the individuals for later identification. This was probably also important characteristics of the animals, to be included in the long term study? if you agree, I suggest you mention this also (it is important to make it clear, why not all the species are suitable for such study).
L.350-351: Do you mean cave communities or cave environments? It is a strange formulation »...Cave communities...have limited seasonality..«. Please check the meaning of this sentence and correct it accordingly.

L161-163: How did you calculate the detectability – it would be useful for the readers to add the procedure/formula here. You used 35 observations (observation pairs, separated by fortnight) per each species?

Here are some language corrections:
L. 17: » dynamism« --> dynamics.
L. 20-21: »We surveyed 16 caves monthly in Central Italy for one year” --> “We surveyed 16 caves in central Italy every month for one year.”
L. 45: »shelter« --> shelters
L. 77: »of 3 m in length for a total of 125 cave sectors among all caves” --> “of 3 m in length, which resulted in 125 cave sectors of all caves ”
Line 78: “three-meter” --> three meters
L. 183: »analysis« --> »analyses«
L. 212 and 222: Use only one term, either »light« or »illuminance« but not both terms, to avoid confusion.
L. 231, 240: Hight, high --> height

Comments to the Supplementary Material
Table S1: Authors should add names of the caves to this list, I cannot see the way the information on distribution of the species. Add the explanations of the column content, to understand what is there – the short word in the names of the columns are not sufficient.
Table S2: Add explanations; what is a sector, what is detection probability.
Table S4: The term community richness is still used in this table. It is not clear, to what the following sentence in the label refers to: »When a continuous variable is included in the model we showed the regression coefficient, while the symbol + indicate the presence of categorical variable.”

Experimental design

Raw data on characteristics of caves are now given in the Supplement, but without names of the caves, or village/town they are close to. Authors do not give very precise coordinates, nor names of the cave – this can be partly understandable from the conservation point of view only. If this is the reason behind this decision, authors should clearly state it. But in any case, access to such data should be enabled. I suggest to add the sentence: »Detailed data may be given upon request« or something similar.

Validity of the findings

L.253-255: As you are not dealing with cave dwelling species, this sentence should be remove/changed. Connecting physiological requirements of the species with cave morphology (and not cave microclimate) is inappropriate and should be rephrased.

L. 272-273: You talk about »food availability« related to Chilostoma, but you have no measure of food availability in your data. Rephrase the conclusion.

Comments for the author

I acknowledge that authors improved the original manuscript and were more precise and careful in generalising the conclusions. There are still some issues that need to be explained better, and some remains of the formulations that authors claimed to have been removed (like the term "community").
I hope my remarks will be helpful in preparing the final version of the manuscript.

Version 0.1 (original submission)

· · Academic Editor

Major Revisions

Please revise your manuscript, paying close attention to the comments of the reviewers. Be advised that your revised manuscript may be sent back to the reviewers.

·

Basic reporting

See comments to authors.

Experimental design

NA

Validity of the findings

NA

Comments for the author

In general, the manuscript is well-written, although the grammar and sentence structure could be improved in several sections, which I’ve noted below. In particular, several sentences in the Discussion read awkwardly and should be revised for clarity. The statistical analyses are robust and appropriate.
The authors should be consistent with terminology. Hypogean and underground are used interchangeably; however, the term subterranean would be most appropriate and consistent with use in recent biospeleological literature.
The authors should check formatting of in-text citations. The use of italics for “et al.” is inconsistent as well as the use of a comma after “et al.”
I recommend more detailed descriptors for the predictor variables, particularly when referring to them in the Results and Discussion. For example, on Line 224 “low and dark sectors” is used. Low (I think) is referring to passage height, but that’s a bit ambiguous.
The term significant is used way too much in the Discussion. Sentences should be reworded accordingly.

Other minor comments and suggested edits:
Line 18: delete “on”
Line 19: change “underground environments” to “subterranean environments, such as caves, …”
Line 22: change “underground” to “subterranean”
Line 23: change “according to” to “related to”
Lines 23-24: “We surveyed 16 caves monthly…”
Line 33: “i.e., high humidity, warm temperature, and low light, …”
Line 35: change “underground to “subterranean”
Line 42: “growth, feeding, and reproduction”
Line 43” change “within” to “among”
Line 48: change “underground to “subterranean”
Line 50: change “show” to “possess”
Line 54: italicize “et al.”
Line 56: change “which” to “that”
Line 58: change “underground to “subterranean”
Line 64-65: “cave species (hereafter cave community) inhabiting subterranean environments…”
Line 67: “…environments, and consequently…”
Line 69: change “hypogean ones to “subterranean environments”
Line 69: “Specifically, we…”
Line 70: change “hypogean” to “subterranean”
Line 76: Is North of the Tuscan Apennines and actual proper noun or should this read northern Tuscan Apennines?
Line 81: “..: 125 cave sectors in total among all caves.”
Line 81: “Three-meter cave…”
Line 82: remove comma after “et al.”
Line 86: “e.g.,”
Line 87: “In each sector, we measured maximum passage height and width…”
Line 88: “(i.e., richness of clefts; Camp & Jensen 2007)”
Line 101: “Scott 1994)”
Line 103: “within each cave sector”
Line 104: “Meta menardi, Metellina merianae, and Tegenaria sp.”
Lines 105-106: “The species were selected not only because of their common presence in caves, but also because they exhibit significant variation in several life history and ecological traits.”
Line 107: change “underground” to “subterranean”
Line 109: change “underground” to “subterranean”
Line 111: change “underground” to “subterranean”
Lines 112-113: Identifying spiders in the genus Tegenaria is quite difficult…”
Line 114: do not italicize “sp.”
Line 115: delete “within gastropods,”
Line 117-118: Slugs in the genus Limax were only identified to genus.”
Line 125: what is “it”?
Line 126: “birth, death, and movement…”
Line 127: “closed populations; MacKenzie et al. 2006..”
Line 129: “…making the application of these methods difficult.”
Line 132: “…and we dedicated…”
Lines 135-136: “This approach allows for heterogeneity of species presence among caves and sectors,…”
Line 138: “…allowing imperfect detection…”
Line 146: “…as a cateogorical variable.”
Line 160: “changes within microhabitats…”
Line 161: “…short periods in which…”
Line 163: “…surveys that were performed…”
Line 167-168: “The approach allows for imperfect detection even…”
Line 170: “…possible; thus, cave identity…”
Line 173-174: delete the last sentence of this paragraph
Line 177: “…richness, we used…”
Line 178: delete the second sentence of this paragraph
Line 178-179: “In addition to the eight focal taxa, we also integrated data…”
Lines 188-189: citations should be provided for R and each of these packages.
Lines 192-193: “A total of 1,918 observations of the eight focal taxa were recorded among the 16 caves (and 125 cave sectors) during the 12-month study.”
Lines 193-198: Much of this data should be presented in a summary table either in the main document or supplemental.
Line 194: “sp.” should not be italicized.
Line 196: “sp.” should not be italicized.
Line 203: “The distribution of species varied among cave sectors over time.”
Line 203: “For all taxa,…”
Line 204: “…survey period, and…”
Line 205: “…were highly variable among taxa.”
Line 205-208: This sentence is awkwardly worded. Consider revising.
Line 208: “cave sectors”
Line 216-217: “with cave sectors with wider passages, lower height, and lower light levels.”
Line 221: By occurrence, do you mean frequency or abundance?
Lines 247-248: What determined variation?
Line 248-250: “During winter, species richness was more evenly distributed among all cave sectors…”
Line 255: “Cave-dwelling species tend to…”
Line 258: delete “significantly”
Line 259: change “underground” to “subterranean”
Line 260: delete “significant”
Line 266: “Geomorphological features…”
Line 269: “…might increase rates of prey capture in webs.”
Line 270: “cave geomorphology”
Line 272: “…sectors where the specific cave geomorphology…”
Line 273: “i.e.,”
Line 273: “Chilostoma planospira was…”
Line 274: “…availability; in fact, this…”
Lines 275-276: “Manenti 2014”
Line 277: “study taxa”
Line 278: “…month of survey; the only…”
Line 278-279: this sentence is awkward. Consider revising.
Line 279-280: same thing with this sentence.
Line 281: “studied taxa”
Line 285: What system?
Line 286: “…temperature of 10-15 C (Lunghi et al. 2015); in summer…”
Line 290: “…suggests that taxa were…”
Line 291: “darkest or most humid”
Lines 300-301: The sentence is awkward. Consider revising.
Line 301: “i.e.,”
Line 318: remove comma after “surveys”
Line 319: “…(Banks-Leite et al. 2014). Nevertheless, the…”
Lines 326-327: “However, this approach also has some limitations…”
Line 334: What superficial ones? Communities in surface habitats?
Line 335: “However, our study…”
Figure 1: “The relationship between species presence and microclimatic features.”
Table 1: “The best five models based on AICc… for each taxon.”
Table S1: the SD should be reported as well.

Reviewer 2 ·

Basic reporting

Contributions that collect systematic data on cave characteristics and relate that to cave use by different animal species are welcome, but interpretations and generalizations need to be carefully done.

Authors are investigating the impact of selected characteristics of caves on occurrence of eight animal species, that are not troglobionts (exclusively cave dwelling species) – which is stated in the introduction. But, even so, they in fact work with two types of non-troglobionts:
- (1) species that occur in caves during certain parts of the year (winter) or during part of the day (and exit during the night). In this case, species behavior is heavily influenced by conditions on the surface.
- (2) species that can be considered as being resident to cave entrances (Meta and Metellina) – again in parts of the caves where there is still some light penetration (close to the entrance). Those parts do not reflect general characteristic of true cave environments , and can be considered ecotone – transition habitat between surface and subterranean realm.

Considering that such different species are considered, with different levels of dependence on (entrance) parts of the caves, I find it problematic to call and analyse them as community. There are also very little (mostly none) interactions among all the species considered, so it is difficult to assume they would react as a »community«. Especially considering different dependence on entrance parts of caves, as stated above. Authors may avoid this problem by using the term species richness (which they do use actually), and avoid the term »community« in these context.

Data on 16 caves investigated, their basic descriptions (coordinates, altitude, cave lenght, depth, lenght of investigated part of the cave in this study etc) are not given among the raw data and should be added – with data on number of sectors per cave. This would make it possible to follow and understand the first part of results, where authors start to speak about 125 cave sectors (should be mentioned in methods), and percentage of surveys – what do these percentages refer to (what is a survey)?

Can authors give more precise information on what is »low light« - they refer to this term in results, but what are the exact values (light was exactly measured)?

Did authors consider including distance from the entrance as one of explanatory variables? One can expect that species are in different parts of the cave not due to certain specifics conditions of the cave, but due to the fact that in spring and summer they have a possibility to quickly leave the cave (no matter the conditions in the cave), while in winter the cave conditions may in fact be more important (L. 249-250; 293-297).

The tile of the contribution is misleading, as at first it indicates that seasonality within the caves is studied in relation to (true) cave-dwelling species. In fact, characteristics of the entrance parts of the caves are being studied, in relation to non-cave species – and this should be clear also from the title of the contribution. And, authors use many non seasonal characteristics of investigated parts of the caves (like cave heterogeneity), which again does not match the title.

Language of the manuscript should be improved, I suggest to give the manuscript to a colleague with good English knowledge. Some words are misspelled, which can be easily resolved. But, there are also some phrases in the text that are not understandable. Here are some examples:
L. 129: »...making it hard the application of these methods.«
L. 146: »To test if species tend to frequent zone with...«
L. 279-280: »...thus the limited excursion of cave microclimate likely have a limited effect on presence.«

Experimental design

Authors have systematically collected data from 16 caves in central Italy, and they should give information on which caves they investigated – as they present the replicas in their study (see the comment in previous section).

It is a general problem in caves that species can be present but are not recorded by the surveyor – authors tried to estimate this effect by calculating detection probability. They are aware that application of the method is limited, so they used only pairwise data only a fortnight apart. It is still not clear how detection probability was calculated from such sub- datasets, and authors should be more specific in explaining this. But, I am afraid that also with this approach, authors cannot remove the fact that some species will leave the cave when conditions outside are suitable. For example, amphibians will leave the cave in spring, so comparing two observations, even if only 14 apart, are deceiving – detection probabilities in both examples are not the same.

Separation into 3 m sectors can be regarded an arbitrary decision, and this is fine. Argument that this is »a home range of small cave-dwelling species« (L. 83), when working with external amphibians, and slugs, is not justified. In addition to that, very little is known about the home range of small invertebrates in caves, the only exceptions may be spiders with more »stationary« way of life. Therefore, I advise the authors not to use »argumentation« for this separation, but define this separations as artificial decision.

It is not clear how authors measured wall heterogeneity (L. 89-91) - did they take more 1 m measurements (and how many) to calculate the representative average for the sector? More explanations needed.

Validity of the findings

Validity of the findings should be considered in the light of initial dataset, which is not on true cave-dwelling species and mostly not done in areas characteristic for true cave environments (but in entrance parts of caves). The results should be therefore interpreted in relation to the groups seasonally using entrance parts of the caves, or using only entrance parts of the caves. Considering these facts, conclusions authors try to make are not supported in the data they analysed:
(1) L. 336-337: »The distribution of species is strongly related to different cave microclimatic features, and to their seasonal variation during the year«
As I mentioned in previous sections, some species are active during summer and are close to entrance parts of the caves due to the fact they can more quickly leave them for (night) feeding – and not due to suitable microclimatic conditions per se. Authors did not exclude first option, which could be done if they included distance to cave entrance as a variable in their models.
(2) L. 339-341: »These environments are usually considered to have a relatively stable microclimate, but we show that seasonality of microclimate features is strong enough...«
There are many published studies on changes of microclimate of caves from their entrance parts to deeper parts of the caves – the effect of surface climate is decreasing from the entrance to deeper parts, sometimes even very quickly. But, considering entrance parts of the caves as typical of »relatively stable microclimate« is not correct and is deceiving – such conclusions cannot come from data that authors have in hand.
(3) L. 345-346: » ... studies on the ecology and distribution of cave-dwelling species should take in account the seasonal dynamism of...«
This is indeed good suggestion, as even deep cave environments can exhibit some seasonality, which is still poorly understood and documented. Unfortunately, authors did not work on this aspect (or they poorly presented it), so concluding with such tone is not wrong per se, but may sound a bit inappropriate.

Comments for the author

I have tried to separate my comments into sections desired, but there may be some overlap between basic and validity of results. I hope the comments will still be understandable.
All in all, I think that such datasets with environmental variables are rare and are worth publishing. I have given many comments, as I believe that more attention should be given to the ecology of actual species and parts of the caves actually studied. Only by being precise with the data at hand, and giving forward conclusions based on data and possibilities (and limitation) coming from them, we can proceed accurately in understanding the subterranean habitats and species, that occur there.
I hope authors will decide to revise the manuscript more in accordance to ecology of species and data they have in hand, and prepare a new version of the manuscript.

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