This manuscript uses long-term data to investigate climatic versus group size effects on reproduction in a cooperatively breeding species. There have been several papers on this topic recently, and so the novelty of this one is the predation aspect. However, the results are quite hard to follow. Justification of the climate windows needs to be clearer: it is difficult to compare between the results and ground them in biological reality as currently written - the biological trends are lost in a discussion of opening and closing windows, fates, and linear and quadratic differences.
I think the authors have missed some key literature in this manuscript. I appreciate that this is a rapidly moving field, but missing this literature does affect some of the novelty claims that they can make for this manuscript. For example, there is a 2020 paper in this journal, Ecology Letters, that shows that group size does not mediate the climate effects on a species that is experiencing a similar climate to the sociable weavers – please see Bourne et al 2020 Ecology Letters. In addition, there is a paper by Guindre-Parker and Rubenstein on group size as a mediator/buffer of climate effects on African Starlings – please see Guindre-Parker and Rubenstein Am Nat 2019. Please also check the recent meerkat papers by Groenewoud and colleagues, which also ask similar questions to those being presented in this ms.
L 69: I don’t quite understand this statement that it is hard to separate physiological effects on individuals from nest predation. Physiology can be directly measured and indeed recent advances allow these to be measured non-invasively in wild animals (eg Moagi et al 2021 J Exp Biol).
L 106: why do the authors expect a less marked effect of predation in larger groups? As stated earlier in the introduction, large groups may actually attract more predators due to greater activity at the nest/burrow etc.
L 130: what is meant by ‘windows’ here?
L 154: I’m not sure what it means by predation being reduced in the subset with information about group size? How was the predation reduction measured? A before/after measure of reproductive success? How often were nests checked on average to determine reproductive success?
L 164: what is a prospecting visit?
L 173: why are there only two possible fates for protected colonies? You have stated above the predation was reduced, but not eliminated at protected colonies. Therefore predation is still a potential outcome for these colonies.
L 174-5: unclear how doing this to the model allows you to study the effect of group size?
L 170-7: More details are needed for the statistical analysis: how were correlated terms dealt with? Are analyses conducted via model selection? Are there random terms? Reading further down, there are details of the stats under following sections. However, AIC is named as used in one section, but the model of analysis of mixed models is not given for the other – is it also AIC?
L 196: what is a used nest?
I think a better justification of the ‘most relevant climatic window’ is needed. What I understand from this is that there are different climate windows for different analyses? Does the calculation that detects the most relevant climatic window always have to find one? As in, it forces a significant window period to be considered even if this window is not more important statistically than other potential climate windows? This seems to be important, because I note the next section uses the climate windows to determine the impact of group size. Therefore the selection of these climate windows needs to be robust to be sure of the group size result.
L208: scaled in what way?
L 212: it’s unclear how this interaction is related to the current question though? Perhaps make this clearer
L 216: ejection has been mentioned several times, and here it is used as a measure of the group size effect on reproductive success. Why is ejection a good measure of this? It is unclear.
L 213: why was group ID not a random term? Where there no pairs/groups that occurred over more than one breeding attempt?
How were rain and Tmax measured? Averaged over the each chosen time window? I don’t find this clearly stated in the methods. Apologies if I am simply missing this. I think getting the climatic variables right is very important, and so how they are described needs to be clear.
L222-226: it’s unclear what the main take-home message of this paragraph is.
L 229-230: there’s something wrong with this sentence: grammatical errors?
Please refer to the tables that show the main results stated (l 229-233, what table is this?). This comment applies to other results paragraphs as well.
L 235: I’m struggling to follow this: what does opening 39 and closing 2 days before the fate date mean? When is the fate date? Is it always the same?
L 241-244: thus what is the main message we take from this? Linear and quadratic models predicted non-overlapping windows that impacted offspring survival the most – which one is most likely to reflect biological reality?
L 268: what is a ‘found window’?
L 283: please provide a stat for this statement.
L 291: what does ‘statistically clearer’ mean?
L 317: I’m not convinced that these effects have been fully separated
L 332: I’m not sure you can conclude this from the analysis: are you saying that specifically under high predation pressure, you observe this effect? Or overall?
L 361: see also Cooper et al 2020 and Moagi et al 2021 for detrimental effects of heat on physiology in arid-zone birds
Table outputs: the confidence intervals and the standardized effect sizes are not given, so the reader cannot see if these intersect zero or not.