Assessing Flight Initiation Distance and Behavioural Tolerance of an Alien Invasive Species, the Sacred Ibis (Threskiornis aethiopicus), in Northern Adriatic Coasts (Italy): Implications for Management of Invasive Waterbirds

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I can offer only a few remarks aimed at improving the paper, visible as Comments on the attached copy of the ms.

Comments for author File: Comments.pdf

Author Response

Comments 1: Actually, control measures have been recently approved by regional authorities in NW Italy (e.g. Deliberazione n. XII/ 4902 Regione Lombardia 01/08/2025) and in Tuscany, were captures and culling are now being implemented.

Response 1: The observation is only partially correct, since it concerns other Italian regions. We added “in the Veneto region” to clarify our statement (Line 86, revised ms.).

Comments 2: You might mean "No ....... measure", therefore better change this because "Any......" would mean measures have been approved or applied

Response 2: Accepted (Line 130).

Comments 3: Strictly speaking, this is just PRESUMED breeding status, because not all the adult birds actually breed during reproductive season, and ths is particularly true for the Sacred Ibis that exhibits a large proportion of non-breeders compared to the active nets at its colonies

Response 3: accepted, "Presumed" was added (Line 146).

Comments 4: This is unclear. Is it just a repetition of habitat effects and responses to environments? If so, it's uneccessary.

Response 4: Accepted, the paragraph was canceled (Line 327). 

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript, “Assessing Flight Initiation Distance and Behavioural Tolerance of an Alien Invasive Species, the Sacred Ibis (Threskiornis aethiopicus), in Northern Adriatic coasts (Italy): implications for Management of Invasive Waterbirds”, provides new insights into the variation in Flight Initiation Distance across six habitat categories; the influence of social, environmental, and observational predictors; and compares locally observed FID values with studies from other regions.

The evidence presented on the behavioral responses of Sacred Ibises to disturbances provides criteria to support management in controlling the spread of this invasive species in human-dominated coastal ecosystems, as well as mitigating disturbances in native communities.

The topic addressed is of interest for the management of this invasive species and is an original contribution with a clear approach to the problem.

The manuscript is well organized and supported by relevant references, adequately describes the methodological procedure, the results are presented clearly and respond to the objectives set, and the conclusions are supported by the results presented.

Based on the above, I suggest a few minor observations:

1) Include a map of the study area indicating the location of the different habitats.

2) In Table 1, use only one decimal point in the Mean and SD data presented.

3) In the results, move the first paragraph of 3.2. Predictors of FID (lines 223-226) to the methodology section.

4) In Figure 1, indicate the point referring to Sacred Ibis in a different color.

5) In the discussion, the paragraph in lines 291-293 requires a supporting reference.

6) In the final paragraph regarding the three implications presented for management (lines 418-424), indicate the limitations or opportunities for implementing management strategies.

Author Response

Comments 1: Include a map of the study area indicating the location of the different habitats.

Response 1: A map of the study area was added (Fig 1).

Comments 2: In Table 1, use only one decimal point in the Mean and SD data presented.

Response 2: Accepted and Table 1 modified accordingly.

Comments 3: In the results, move the first paragraph of 3.2. Predictors of FID (lines 223-226) to the methodology section.

Response 3:Accepted, moved (now Line 220-223).

Comments 4: In Figure 1, indicate the point referring to Sacred Ibis in a different color.

Response 4: In Figure 2 (formerly Fig 1) the Sacred Ibis is now indicated with a red dot.

Comments 5: In the discussion, the paragraph in lines 291-293 requires a supporting reference.

Response 5: Two references added (Line 311).

Comments 6:  In the final paragraph regarding the three implications presented for management (lines 418-424), indicate the limitations or opportunities for implementing management strategies.

Response 6: A paragraph on this topic was added  (Lines 452-465).

Reviewer 3 Report

Comments and Suggestions for Authors

The authors studied flight initiation distance in T. aethiopicus in Northern Adriatic coasts over a relatively long time period. The work is generally clearly presented and appears to me to be statistically robust, although I am not a statistical expert. I have no major issues with this paper and would support its publication.

Some points for consideration:

line 33-34: escapes from zoological gardens

line 87: please revise; do you mean 'behaviour...has not been externally modified over this time period' ?

2.1 study area: a simple map is often included in such publications, and I thin it does help the reader with orientation.

3.2 predictors of FID: could these results please be presented as a table or figure? they are the most important numerical conclusion of the paper and would be better ir more visually accessible. Thank you.

Figure 1. It would be interesting for the reader if the authors could comment on the other species falling below the 95% CI line (sanderling, common sandpiper, ruddy turnstone) as to whether there is an obvious or hypothesised explanation for these?

The discussion is relatively long but is all relevant and interesting.

References: please proofread carefully with regard to Genus species names for italic font and upper case for Genus only - a number of corrections needed. 

Author Response

Comments 1: Line 33-34: escapes from zoological gardens

Response 1: accepted (Line 34)

Comments 2: Line 87: please revise; do you mean 'behaviour...has not been externally modified over this time period' ?

Response 2: Accepted, paragraph modified accordingly (Lines 87-88).

Comments 3: 2.1 study area: a simple map is often included in such publications, and I thin it does help the reader with orientation.

Response 3: A simple map was added (Fig. 1).

Comments 4: 3.2 predictors of FID: could these results please be presented as a table or figure? they are the most important numerical conclusion of the paper and would be better ir more visually accessible. Thank you.

Response 4:  Table 2 was added, with all the multiplre regression results.

Comments 5: Figure 1. It would be interesting for the reader if the authors could comment on the other species falling below the 95% CI line (sanderling, common sandpiper, ruddy turnstone) as to whether there is an obvious or hypothesised explanation for these?

Response 5: A new paragraph was added about this aspect (Lines 362-369).

Comments 6: The discussion is relatively long but is all relevant and interesting.

Response 6: One paragraph (Lines 327-330) was canceled, being probably redundant. 

Comments 7: References: please proofread carefully with regard to Genus species names for italic font and upper case for Genus only - a number of corrections needed. 

Response 7: All the references have been checked and corrected where nedeed.