PREreview of Small is big: A new conservation paradigm for amphibians

Concise, but informative summary of the preprint

The authors identify an important conservation challenge, which is the selection of where to create new protected areas (PAs), and how small or large these PAs need to be to protect biodiversity effectively. This challenge is key for amphibians, who are increasingly vulnerable to extinction, and whose small ranges are rarely prioritized in the creation of new protected areas. To evaluate whether PAs are adequately protecting amphibians at the global scale, the authors assessed the coverage of an impressive number (over 7000 of the ~8500 recognized species) of amphibian species’ ranges by the PA network over time. They found that threatened amphibian species are poorly covered by protected areas, and that protected area establishment has also slowed globally since the early 2000s. The authors suggest microreserves as a solution to help improve the coverage of amphibian species’ ranges.

The result is a convincing argument for the establishment of small protected areas (or, microreserves) as a way to more effectively protect amphibian species, in order to meet biodiversity conservation goals. Their argument is supported by concrete recommendations for the size of new protected areas, and the regions in which they would best protect amphibian diversity.

Big-picture comments

1. Good/Excellent things

The authors have truly made an effort to take a global take on this matter and have tried to curate the most complete dataset possible. This must have for sure been a massive undertaking, so great job!

We appreciate the discussion that one of the limitations of this study is that the dataset for PA’s is most likely not complete and government-dependant when it comes to exactly what is deemed a ‘suitable enough’ PA to be included in the database

Overall, we found the preprint very comprehensive and we found the paragraphs to be coherent. There is one good introductory sentence in almost most of the paragraphs that makes it easier for the reviewer to find out the summary of the paragraph and then the supporting sentences are very well connected. 

1. Things to be improved

One thing that was not immediately clear in the methodology is dealing with species that might occur in two different regions but may be protected in one but not the other. Is this species still considered protected in the region that it is present in but not protected since it is protected elsewhere in its range?

A discussion that is missing for me in the conclusion is thinking bigger than just protecting a species but also the external factors that might degrade the quality of the environment. E.g. Protecting the segment of the waterway where an amphibian species might occur is good but conserving a larger portion of that waterway might go a long way in ensuring the quality of the environment is suitable for the amphibian species.

Another point that will be hard to quantify but might be worth considering - and this relates somewhat to Figures 2 and 4. It is shown that PAs do not contain threatened species. However, this could be an ‘artefact’ of these protected areas being effective in elevating the conservation status of a species from threatened to ‘non-threatened’. For example, the older parks (Fig 4B) might have originally been established to protect a threatened species and consequently that species is no longer considered threatened. Again this might be out of the scope of the but might still be with contemplating

We think the preprint lacks providing enough reasons for protecting amphibians and in our view, it is mainly concerned with the datasets and their mass extinction rather than their importance to the biodiversity or the other groups of species. It might have been better if the authors talked a little bit about the fact that other species are dependent on the amphibians and if their extinction continues, those species might be (or have been already) negatively impacted. That will make the preprint super important to the eyes of the reviewers once they send it to a journal!

After the conclusion part, they can add another title and in summary, mention the main points on how to conserve amphibians. We would again paraphrase the last sentence of the “Microreserves:...” section under this new title just to recap.  

1. Small-picture things

   1. Good/Excellent things

Fig 5 manages to effectively communicate a lot of information in a single graphic that still feels digestible.

1. Things to be improved

Please cite all the packages used for analyses (not just list them).

Look at the contrast in figure S2. Due to the small size, the small green polygons are challenging to see, particularly in panel A. Another solution might be to have a vertical figure as opposed to a horizontal one as it will allow you to make the panels a bit bigger.

For Fig 4A it might be cool to also split out the line by large and small PA’s (since the columns are already split out as such)… Also for this figure. Mage some more whitespace between the two panels. The text is cramped.

Figure 3. Please expand on the colour gradient in panel A in the figure caption. It was not immediately clear to me what the gradient represented.

Fig 1 is not needed in this manuscript per se. It detracts from the core results.

In fig. 5, the titles can be smaller in size as the big size (e.g., Protected Unprotected) makes the readers confused if they have already not seen the pie charts.

The author mentioned some terminologies, especially “six mass extinction” and megafauna” several times throughout the paper without providing a short description about their meaning. By adding this, the preprint can become much more understandable for the nonexpert readers like me.

This sentence “Amphibians have existed on earth for over 300 million years, yet in just the last decades there have been an alarming number of extinctions”, which is written in paragraph 3 of the Introduction section, is an important fact and I think should be moved to the introductory sentence of the same or the previous paragraphs. 

The “protected Area (PA)” has been once used at the beginning of the Introduction and don’t think it is enough to only mention the abbreviation in this section as far as they mentioned the phrase in the beginning.

Competing interests

The authors declare that they have no competing interests.