INTRO: Identifying the traits that make species vulnerable to extinction might help us predict the outcome for those less known. The authors gathered extensive information on trait responses to extinction risk from 122 publications, across all taxa, spatial scales and geographical regions. The most interesting results were that several traits for which we lack data for most species often rank high. The "bigger body size is bad" rule is however not supported across all taxa, but fortunately this trait becomes usually very informative in those studies that investigate its interaction with extrinsic and other intrinsic traits. The authors suggest that further studies should analyse interactions between traits and sources of threats.
MERITS: The study question is highly relevant for practical conservation.
CRITIQUE: The data and methods seem appropriate, but it is a bit unclear how you analysed the data: simply tabulated the data or did you use some formal analyses.
DISCUSSION: Inferences are justified and the abstract is generally well written.
- - -
INTRO: The authors present the results of analyses whose objective is to pinpoint the most common traits that make some species of vertebrates (mostly mammals and birds) more vulnerable to extinction risks. Geographical range size stands out as the best predictor. Lack of and incomplete data impede the potential of the study to make predictions on some traits, and body size can be informative in some cases.
MERITS: The study aims at finding traits that are the most common among species at risk of extinction, most likely in order to be able to better anticipate which species may be at risk in the future. The analyses are based on a large dataset and should, thereby, have some statistical power (provided that the effect size is large enough, too).
CRITIQUE: It is not very clear which traits constitute a risk for species. The fact that species with a small geographic range are more at risk (which is not explicitely mentioned in the abstract) is rather obvious, but the other traits described do not seem to provide any help to conservation managers as to which species are more at risk and how to tackle their conservation.
DISCUSSION: To our knowledge, the topic of the study is new and deserves to be examined in order to see whether this could be a promising research path to undertake species conservation. However, the study could benefit from being more specific as to which traits make some species more vulnerable; this could lead to better conservation management strategies.
- - -
INTRO: The work describes a review of the extinction risks of species based on 122 publications. Threat categories of only a small part of species have been analysed, and therefore it is highly important that vulnerability of species to extinction is properly studied.
MERITS: This is an important study to enhance redlisting of species and properly preserving threatened species. It is reasonable to study species traits in order to find congruencies in species threats and to detect exposure of species to extinction.
CRITIQUE: It was not clear to me whether the authors studied all redlisted species, redlisted species of data deficient (DD) or all species in their 122 publications. How did you select these 122 publications? By using som key words in the Web of Science or what?
DISCUSSION: Species traits are usually rather similar in closely related species (in genus or in family). How did you take this issue into account in your analysis?
