Considering What Animals “Need to Do” in Enclosure Design: Questions on Bird Flight and Aviaries

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors Тhe manuscript is well structured and covers current issues related to the welfare of captive birds.
The authors provide appropriate directions for future stakeholder studies to analyze the issue in depth

 

 

Author Response

Thank you for the feedback. We are pleased that the reviewer can see the value of the paper, especially that we have attempted to bring this challenge in modern day bird care and management to the attention of those building and creating enclosures in zoological collections.

Reviewer 2 Report

Comments and Suggestions for Authors

This paper seeks to explore the criteria necessary to promote the welfare of birds in captivity by meeting, so far s possible, their needs and motivation to fly. The exploration is soundly based on the four principles of Tinbergen, Causation, Development, Function, Evolution. However, the MS assumes all readers will know these four principles and does not actually describe them until Fig 3, line 324. Fig 3 could become Fig 1.

 Table 1 gives a fairly comprehensive summary of the reasons why birds fly, their motivation to fly, and possible physiological and behavioural consequences of restraints if these behaviours.  The subsequent text describes various things zoos might do to address these things.  What this paper lacks are any suggestions as to the application of the scientific method, e.g. the design of controlled experiments applying different constraints on flight behaviour (in the same or different aviaries) and observing the consequences for different aspect of behaviour and fitness.

 While it recognises the (obvious) fact that there are different motivating factors for different classes of birds e.g. ground feeding precocial v. air feeding altricial, v. water feeding, the paper would be improved by the inclusion of (e.g.) a table setting out a provisional list of priorities for these three classes and how they might be addressed by studies on these birds in different captive environments.

 

 

Author Response

This paper seeks to explore the criteria necessary to promote the welfare of birds in captivity by meeting, so far s possible, their needs and motivation to fly. The exploration is soundly based on the four principles of Tinbergen, Causation, Development, Function, Evolution. However, the MS assumes all readers will know these four principles and does not actually describe them until Fig 3, line 324. Fig 3 could become Fig 1.

Thank you for the comment and useful feedback. We have edited the manuscript to include explanation of these main points in the introductory part of the paper (lines 75-78).

 

 Table 1 gives a fairly comprehensive summary of the reasons why birds fly, their motivation to fly, and possible physiological and behavioural consequences of restraints if these behaviours.  The subsequent text describes various things zoos might do to address these things.  What this paper lacks are any suggestions as to the application of the scientific method, e.g. the design of controlled experiments applying different constraints on flight behaviour (in the same or different aviaries) and observing the consequences for different aspect of behaviour and fitness.

Thank you for the comment. We have included ideas for methodological study in Table 1 to show how data to answer such questions could be generated. However, we have expanded on this based on the reviewer’s suggestion underneath this table, line starting 159-175, to show how experimental situations could be set up and such data used to infer a bird’s behavioural responses to captivity.

 

While it recognises the (obvious) fact that there are different motivating factors for different classes of birds e.g. ground feeding precocial v. air feeding altricial, v. water feeding, the paper would be improved by the inclusion of (e.g.) a table setting out a provisional list of priorities for these three classes and how they might be addressed by studies on these birds in different captive environments.

Thank you for the useful comment. We have included such a table in the text at lines 274-293. We have examined the different forms of foraging strategy as you mention and we have included the priorities that a bird of this nature would need to have within an aviary, and how research questions could be used to check whether these priorities are being met. Thank you for the useful addition to the paper.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors present the problem of keeping birds in breeding in zoos. As the main factor responsible for the lowering of the standards of bird welfare, there is limited flight space. Although it seems obvious, meeting the full possibility of flight in a closed space is mutually exclusive. The authors have raised many questions about the quality and feasibility of flight, but they are nevertheless interspersed with other aspects and assumptions that certainly support the concept of well-being, but introduce chaos into the manuscript.

The first impression in the evaluation of the work is quite unpleasant and this is not due to the assumptions of the manuscript, but to the lack of clarity and research consistency. In my opinion, the topic of the thesis is incorrectly formulated and does not contribute to considerations resulting from the goal set by the researchers and subsequent conclusions. It needs to be redefined.

The overall reception of the work is more in the form of a guide than a scientific discussion, asking research questions is justified, the search for existing answers based on research results is necessary, but I do not know what would result from so many aspects raised in the manuscript.

Change of the topic and specification of the topic, and limiting the discussion to the search for the achievement of the purpose of the work corresponding to the topic and summarized in the conclusions. The need to redefine and assess the ability and need for flight.

Search for behavioural behaviours that indicate incorrect enclosure design, or finally creating a formula for assessing the welfare of birds in zoos are just a few questions that arise while reading the manuscript, unfortunately there are many more. Although they are absolutely correct in my opinion, they are only a well-known need and trend, and do not result from analyses or discussions of the authors' literature. Each of these aspects is addressed in the manuscript, but too many of them lead to an insufficient presentation of the problem and its possible solutions, which reduces the value of the work.

Summarizing

The manuscript is very important in terms of the issues raised, for all zoos and other bird breeding facilities, but its clarity and thus research credibility is diluted by too many assumptions. I recommend changing the topic, grouping the problems raised (considering giving up some of them - I leave it to the authors' consideration), limiting the number of questions asked and rewriting the conclusions so that they become an answer to the manuscript and achieve the goal described by the authors.

Author Response

The authors present the problem of keeping birds in breeding in zoos. As the main factor responsible for the lowering of the standards of bird welfare, there is limited flight space. Although it seems obvious, meeting the full possibility of flight in a closed space is mutually exclusive. The authors have raised many questions about the quality and feasibility of flight, but they are nevertheless interspersed with other aspects and assumptions that certainly support the concept of well-being, but introduce chaos into the manuscript.

Thank you for the feedback and comment. We apologise that you find some areas of the manuscript chaotic. Based on the feedback from other reviewers we have clarified some of the terminology and explained the behavioural framework (i.e., Tinbergen’s Four Questions) that can be used to understand animal behaviour and, in this case, work out whether or not birds can fly in a meaningful way in an aviary. We hope this clarifies the main background to the work.

 

The first impression in the evaluation of the work is quite unpleasant and this is not due to the assumptions of the manuscript, but to the lack of clarity and research consistency. In my opinion, the topic of the thesis is incorrectly formulated and does not contribute to considerations resulting from the goal set by the researchers and subsequent conclusions. It needs to be redefined.

That you for the comment. We are sorry that you find our manuscript unpleasant. We have changed the paper from a Review to a Commentary to show that we are posing new ideas and that we do not have answer to the challenge (i.e., “do birds like to fly?”) yet from the available information in the scientific literature. Based on other reviewer feedback, we have expanded on the potential of the scientific method to meet this research challenge. We have also clarified our goal of this manuscript at the end of the introduction (lines 125-131) and start of the conclusion (lines 503-505). Thank you for the feedback in helping to improve this paper.

 

The overall reception of the work is more in the form of a guide than a scientific discussion, asking research questions is justified, the search for existing answers based on research results is necessary, but I do not know what would result from so many aspects raised in the manuscript.

Thank you for the comment. As we have altered the nature of the paper to a Commentary, we feel that we have provided evidence for the integration of our ideas. There is no evidence for this topic area in the scientific literature. But it is an important bridge between wild ornithology (i.e., bird ecology) and avian management under human care. We have included new information that shows the link between wild characteristics (in our example feeding ecology) based on the request of another reviewer and we have shown how basing bird care on such fundamental aspects of their evolution could advance aviary design, bird husbandry, and ultimately promote good welfare. We hope this clarifies our approach and concept.

 

Change of the topic and specification of the topic, and limiting the discussion to the search for the achievement of the purpose of the work corresponding to the topic and summarized in the conclusions. The need to redefine and assess the ability and need for flight.

Thank you for the comment. We feel that we have synthesized our explanation more clearly in the discussion and conclusion based on the feedback from other reviewers that have asked for expansion of some key points to show the integration of ecology and wild information into bird care. We feel that these are important points to have included to show the bridge between what we know about wild birds and how such information should form the basis of their management under human care.

 

Search for behavioural behaviours that indicate incorrect enclosure design, or finally creating a formula for assessing the welfare of birds in zoos are just a few questions that arise while reading the manuscript, unfortunately there are many more. Although they are absolutely correct in my opinion, they are only a well-known need and trend, and do not result from analyses or discussions of the authors' literature. Each of these aspects is addressed in the manuscript, but too many of them lead to an insufficient presentation of the problem and its possible solutions, which reduces the value of the work.

Thank you for the feedback. We have struggled to understand what the reviewer means in this section. Notably, what “behavioural behaviours” are and there is a lack of information on how to assess bird welfare in the literature. We have included novel ideas to do this. In the form of Figure 2 and in Figure 4. We find no literature that examines the question of “do birds like to fly”? in relation to their care and management so we are confident that we have included novel information and we present this in a way that summarises the link between ecology and natural history, aviary design to meet the ecological needs of the animal, and ultimately how the bird can attain good welfare. We thank the reviewer for their thorough review of our paper and the opportunity this gives us to further explain and define our ideas and key goals of this manuscript.

 

Summarizing
The manuscript is very important in terms of the issues raised, for all zoos and other bird breeding facilities, but its clarity and thus research credibility is diluted by too many assumptions. I recommend changing the topic, grouping the problems raised (considering giving up some of them - I leave it to the authors' consideration), limiting the number of questions asked and rewriting the conclusions so that they become an answer to the manuscript and achieve the goal described by the authors.

Thank you for the comment. We have added to the conclusion to explain our goal and we have rationalised the main aims of the paper in the introduction (explaining our link between ecology, aviary design and welfare). We have described a key aim of the paper is to present research ideas and a novel way of examining how birds live in zoos to improve their care. With the added extra information from other reviewers and from the editor, including new papers on how free-flight training is essential to conservation value of birds, we feel that we have a stronger overall narrative to our work. We thank the reviewer for their helpful and useful comments on our paper overall and the time taken to read and digest our thoughts and ideas.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

You have satisfactorily addressed the issues raised by the referees. The new Table 3, in particular, addresses the question of how to give special attention to the foraging and eating behaviour of birds, in the design and management  am of aviaries. 

 

Reviewer 3 Report

Comments and Suggestions for Authors

I accept the manuscript for publication in its current form after all corrections made by the authors. The article has become more readable and systematized by becoming easier to read by the reader. The research and substantive value does not raise any objections.