Moose Management Strategies under Changing Legal and Institutional Frameworks
Round 1
Reviewer 1 Report
The authors examine moose population estimates and hunting bags of the last 48 years to investigate how sustainable the moose management has been in Lithuania. The analyses are easy to follow but comparing rates of change among years, and long term changes in population status. They compare these statistics at the country level and county level and discuss their results in the context of regulatory changes over time. The research provides an interesting case study of how moose management has evolved, especially given the lack of clear management strategies. It is therefore helpful to have this information published so that comparisons can be made among countries and to develop a broader view of the development of moose populations across Europe over time. The authors frame their research question in terms of how sustainable the management has been, and therefore the research certainly fits the research scope of the journal, however as I outline below, it would be helpful to have a broader, clearer view of what they consider sustainable. I also have some concerns about how some of the results have been interpreted, and the discussion section is in my view too long. Instead of discussing the results in the context of previous research done, large parts of the discussion read as a background section which is not entirely relevant to the goals of the study. I hope my recommendation help the authors in refining certain aspects of the article before publication.
Introduction: Your objective is to investigate whether moose hunting is sustainable – but you never fully describe what is considered “sustainable”. The word sustainable carries many considerations, for example, in your description of Sweden’s management system it is emphasised how the moose population needs to be managed in balance with natural resources, but also with human interests for e.g. due to collisions or browsing damage. The population should also be large enough to be hunted. Your study seems to define “sustainable” as being constant – i.e. the rate of growth should not change/stable over time (it is not clear whether it should be growing or have a growth rate of zero). A classic example is the last 10 years, the growth has been quite constant (therefore sustainable?) but is the high(er) population size of today sustainable in terms of consequences for the ecosystem and human-wildlife conflicts. In addition, one could consider it a huge conservation success that moose increased from 250 individuals in 1954 to ~10,000 individuals by 1974.
Fig. 3: Plotting the values of I(t) at present is non-intuitive. What values are on the x and y-axis. I presume you are comparing I(t) to I(t-1) to somehow reflect changes over time. I believe it would be easier for readers if the results depict year on the x-axis (1962 – 2020) and I(t) on the y-axis. Values above zero depict a growing population and values below 0 depict a decreasing population. Such a graph makes it easier to distinguish growing from decreasing populations, and also emphasises the period with drastic change in I(t).
L153 – L161 and Figure 4: I disagree with your interpretation of the results here. You are regressing years which ultimately led to catastrophic failure in management (your outlier years). Each period is defined by gradually increasing hunting bag until it stabilised, but these did not respond soon enough to falling moose numbers. Consequently, an outlier year occurs, which is characterised by drastic falls in hunting bag due to a lagged response in the fall of moose numbers. Have you tried simulating your recommendations – i.e. with a starting moose population of X and a hunting bag of Y – what happens to the state of the population if you increase the moose population by 1 unit and increase the hunting bag by 2.9219 units – what happens of n number of time steps (e.g. 40 years). I worry that you have misinterpreted your results of what is sustainable, and are therefore making management recommendations that may be detrimental for the population of moose.
L175 – L184 and Figure 5: Although first estimates were available in 1993, this was also a period when the entire moose population was declining rapidly before gradually increasing again (your Fig. 2). Give the variation in population size, and missing data, would it not be easier to depict this data from 1999 when data is available for all counties. This makes the comparison over the following 20 years easier to compare (if they all start from 100, compared to now when there is already a very large difference in 1999 between the largest and smallest populations).
L222 – L242: Please provide a description in the methods about where this environmental data comes from and the time period it covers. The brief description in the legend of Table 3 isn’t sufficient in my view.
L223 – L227: It is a strong assumption that forest cover change in 2014 – 2018 is representative of the entire study period (1993 – 2020). Data sources like the Copernicus Land Cover provides satellite images since 1990 (in different period blocks) and therefore provide a much more accurate representation of your study period. The coverage include Lithuania https://land.copernicus.eu/pan-european/corine-land-cover/
L237: If your response variable is density (i.e. animals/km2) – why would you expect a correlation with the area of the county, since area has effectively been removed from the equation by using density.
L253: I should hope so. A value of 0.5 indicates a 50% change in population size – this would be extremely dramatic for a large ungulate like the moose.
L253: Your I index of moose population is actually very similar to general population growth rates (i.e. you are comparing the population in one year to the next, which is effectively the sum of mortality and reproduction from all causes). It would be helpful to include some discussion/information of potential growth rates of moose populations. For example, a twenty year study of moose in British Columbia found a maximal increase (i.e. population growth rate) of 10% (Schrempp et al. 2018, MOOSE POPULATION DYNAMICS DURING 20 YEARS OF DECLINING HARVEST IN BRITISH COLUMBIA, ALCES, 54 (101 – 119).
L253: Related to above, a large uncertainty of your research is the reliability of population estimates, which you openly admit in the method and justify your choice of using “official” estimates, which I commend you for. However, I think it would be helpful to include a small section in the discussion about the reliability of the data and how this may influence your interpretations. I imagine there are large confidence intervals around the true population size. Has the quality of estimates changed over time, and can years with extreme changes in I(t) be due to inaccurate estimates of the population size?
Section 4.1 (L265 onwards): I understand why it may be interesting to include all this background info, but it is very detailed and rather than forming “Discussion”, it is more a detailed history of hunting regulation in Lithuania. The section would benefit with a critical evaluation to summarise the key points that are relevant for discussion the results of your manuscript.
Section 4.2 (L356): Again this is a very detailed description of the management systems in other countries, but with no direct link (that I see) to your own research and moose management in Lithuania. Your article is not presented as a review of moose management in Europe, so please only discuss what is necessary in the context of the research performed. Outline why is it important to compare management in other countries to that of Lithuania. It would also help to only identify the key differences in management approaches rather than providing a general description of the approach in each country.
Author Response
Please find answer to comments attached
Stay safe
Linas Balčiauskas
Author Response File: Author Response.pdf
Reviewer 2 Report
I have only minor corrections, some questions and suggestions to the content of the MS. They are shown in the margins of the MS or highlighted in yellow in the attached text
Comments for author File: Comments.pdf
Author Response
Please find answer to comments attached
Stay safe
Linas Balčiauskas
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thank you for your responses, clarifications and improvements to the manuscript. I am happy with the changes made and only have a few very minor textual comments.
L100: The first sentence isn't needed - you now provide this information in the legend of the figure
L101 to L104: I appreciate your efforts to try and explain the graph more, but these changes are unnecessary. It largely repeats the sentence of L105 and L106. My point was that I didn't know what was on the x & y axis (which you now describe above) - and I still don't personally see the added benefit a connected scatterplot provided compared to a simple time series with a point and/or line for each year. The main information is whether l(t) is increasing or decreasing (i.e. 1st/3rd quadrants) - which is achieved in a line graph when points are above or below 0. The 2nd/4th quadrants don't add any value in my opinion. But it is mostly about personal preferences and you obviously like your scatterplot so it is also fine for it to stay that way. Adding the years has helped improve the scatterplot as well.
L170 - Remove the part in bracket, i.e. ("we are grateful to one of reviewers for points this out"). This is uncharacteristic for a scientific artile. If you wish, you can add to your acknowledgements that you thank two anonymous reviewers for the comments.
L236 - "was 2.6% for the entire country [17]"
Author Response
thank you, our answer is attached
Linas Balčiauskas
Author Response File: Author Response.pdf