Spatial Segregation between Red Foxes (Vulpes vulpes), European Wildcats (Felis silvestris) and Domestic Cats (Felis catus) in Pastures in a Livestock Area of Northern Spain

Round 1

Reviewer 1 Report

General comments

I would like to thank the authors for this interesting paper. I consider the subject of the paper very interesting. However, I would suggest the authors to clarify some major points. In particular I’m referring to some problems detected in the study design, like i) the application of a buffer of 500 meters as reference area, while I personally consider that the detection and correct identification of animals at that distance can be really problematic, ii) the application of detection probability linked to the observation of animals at different distances from the observers, iii) the accuracy of differentiation between domestic and wild cats, for animals with grey coat and at great distance from the observers (and above all at night).

Specific comments

Line 16 : why the study has been carried out  only in summer? Please clarify.

Line 24-25: I would remove this sentence as it repeats a concept already expressed in previous lines

Line 26: are there other large predators in the study area? If yes, were they observed during your monitoring sessions and should they have taken into account in your results?

Line 60: which other mesocarnivore species have been observed in the study area? What about their possible role in shaping your observed dynamics? Please provide more explanation why you focused only on these three main mesocarnivore species.

Line 76-77: fox is also a very opportunistic species using human waste, or livestock (poultry, rabbits, etc) as a source of food. How is the situation of the study area under this perspective? Have these factors been taken into consideration?

Line 108-109: please provide a bit more of rationale at the basis of the period of the year selected for monitoring operations.

Line 111-113: the duration of monitoring was not homogeneous for the different periods of observation across the day. Could this have impacted your results? Please comment on that.

Line 112-113: why did you apply a different monitoring schema in 2016?

Line 114-123: I have a problem with the transect monitoring design. Please confirm if my understanding is correct. Daily transects were 53 km long, repeated twice, at a speed of 20-30 km. Night transect were 10.8 km long, repeated also in this case twice. This means that different areas/transects were observed during the day and during the night? Is my understanding correct? If yes, the time needed for monitoring seems to me too short for daily monitoring (it should take almost 4 hours) and too long for monitoring at night (it should take maximum 1 hour). Sorry for the long comment. Just trying to be sure I correctly understood your methodology. Moreover, why daily and nightly monitoring were carried out using different transects?

Line 124 – 126: please specify better this point. I think that using observations out of your monitoring schema might introduce bias in your results. Please provide elements to justify your choice.

Line 127-131: are lagomorph species present in the study area? If yes, why they were not monitored as potential prey? I imagine their distribution may also shape and influence your observations.

Line 150-151: this means that, potentially, distance to river and distance to forest were highly correlated. Have you tested and excluded this possibility?

Line 156-157: I have a problem with the 500 meters buffer area used as limit for observation probability. From my experience the possibility to observe small animals at distances greater than 250-300 meters is very low. This possibility is even lower if we consider monitoring carried out at night. Please comment on it.

Line 158-160: have you applied any “distance weight” to balance the different probability of observation at different distances? Probability of observation decrease with increasing distance from the observers. I think this should be taken into consideration in your analysis.

Line 199: how did you ensure a correct differentiation between domestic cats and European wildcats, above all at long distances and at night? It seems to me the probability of misclassification is quite high, above all with subjects with grey coat. Please comment on that and provide more robust explanations on this point.

Table 3. I would suggest converting this table keeping all the years together and not splitting by year.

Table 4. Same suggestion provided for table 3. I would present all the years together.

Result general comment: I would like to see in the results two additional points that would help to better understand the analysis:

• Number of observations done during the different times of the day and differences between observations done during the day and at night by species
• Descriptive statistic (average, min, max, quartile, etc) of the distance of the animals from the observers by species (during the different times of the day and at night)

Discussion: I like the discussion very much, however there are several points that I would like the authors to clarify better and that could change / add some discussion points. In particular, I consider that more details and emphasis should be provided about possible factors that may bias the results like the influence of different detection probability with increasing distance from the observers, the real possibility to clearly differentiate between domestic and wild cat for animals with grey coat (and above all at night), the use of an “observation buffer area” of 500 meters, that too mee is not realistic.

Author Response

All comments have been addressed, please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This article uses drive transects to study spatial distribution/segregation of 3 mesocarnivores. The methods and analyses appear adequate. This was a considerable amount of work for across four years and would be interested to those studying spatial dynamics in mesocarnivores and it has implications for different areas of ecology. My principal critique is that of data presentation. In my opinion, table 2 and 3 would be much better represented for the reader if graphs to represent this data were provided. It would be much easier to evaluate and interpret the data as well as compare the difference between years in the data presented. Please provide a paragraph in the discussion that elaborates on the limitations of the methodologies used (drive transects) for making inferences about the populations studied. 

Author Response

All comments have been addressed, please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I would like to thank the authors for having addressed the point raised.

I feel the paper is now clearer and suitable for publication.

Author Response

Thank you for your comments.