Reviewer comments

Paper 7 assignment This is a raw manuscript that was submitted for publication. Comments from an anonymous expert reviewer are appended below. 1. 2. 3. 4.

Do the data in the submitted manuscript make a significant advance over the data previously published by Rutberg (1987)? (2) Do you think mosquito activity (unmeasured in this study) might be an important influence on horse behaviour? (2) Was the reviewer fair and balanced in their criticisms of the study? (2) Write a decision statement about whether or not this manuscript be published in the journal and justify your decision. There are three main areas to think about: 1: Does the experimental design test the hypothesis described in the introduction? 2: Do the conclusions follow logically from the data? And 3: Does this study contribute novel insights to behavioural biology? There are two ways a decision statement can go: a. Reject – the flaws in the manuscript are fatal and unfixable b. Tentatively accept pending revision – the flaw are minor and can be addressed in revision In your decision statement, state what you think the major flaws are (you may or may not agree with the reviewer’s opinions) and whether these flaws can be adequately addressed in revision (choice b) or not (choice a). (4)

Reviewer comments: GENERAL This is a well written account of some very interesting research that shows that horse comfort movements are predictors of fly numbers. However, the paper would be improved by some more explanatory detail of some entomological points and by taking into account results of other published work on the same topic in other animal systems. Some of these are listed below. SPECIFIC The pages of the ms are unnumbered. The comments below refer to page numbers beginning with the abstract page as page 1. Pages 1 and 4. The observations were conducted in June and then again in August, but no mention is made of the relative abundance of the different species of the various biting insects involved for either period. However, with 2 species of Tabanus, 2 of Chrysops and Stomoxys calcitrans involved it is likely that their differing phenologies would have led to differences in their relative abundances in early June when compared to those in late August. Can the authors supply any data on relative abundances e.g. from trap catches at the site, preferably at different times? If so, and there were differences found, then data on differences in the fly numbers in different habitat types would need to be re-analysed according to month of observation. Similarly, can the authors discount differences in the timing of daily biting routines as an alternative explanation for the significant effect of temperature that they report, given that their observations spanned the period 1030 to 1930? There are reports of the effects of host defensive movements affecting fly biting rates in tsetse flies feeding on cattle (Baylis 1996, Torr & Mangwiro 2000), warthog (Torr 1994) and a variety of stationary hosts (Vale 1977) that are relevant to the discussion of defensive reactions, effects of differences between hosts as well as that on stationary versus moving hosts. For instance, Torr & Mangwiro reported higher rates of defensive movements in young cattle and thus more flies fed on the older animals and they also found differences when more than one host animal was exposed. Similar results have been found with mosquitoes feeding on cattle (Prior & Torr 2002). Page 9. It is not only CO2 that attracts biting flies and so it may not be metabolic rates that are determinants of host attractiveness. A cocktail of chemicals is involved (e.g. see Hargrove et al. 1995) in the attraction of most biting flies in addition to variation in host size, colour and shape. Variations in the constituents of the odour cocktail between different individual host animals or between animals of

different sexes may account for differences in attractiveness and so the differences found between the sexes of the horses are unsurprising and consistent with other studies. Page 3 Lines 3-4. “…,have spend…” is meaningless. Suggest use “spent”. Page 3. Four lines from the end: There are no authorities given for the scientific names of the insects: nigrovittatus should be underlined. Page 5 penultimate line. Replace “it was” with “they were” [Data are plural].

References Baylis, M. (1996) Effect of defensive behaviour by cattle on the feeding success and nutritional state of the tsetse fly G. pallidipes (Diptera: Glossinidae). Bull. Ent. Res. 86: 329-336. Hargrove, J. W., Holloway, M.T.P., Vale, G.A., Gough, A.J.E. & Hall, D. R. (1995) Catches of tsetse flies (Glossina spp.) (Diptera: Glossinidae) from traps baited with large doses of natural and synthetic odour. Bull. Ent. Res. 85: 215-227. Prior, A. & Torr, S. J. (2002) Host selection by Anopheles arabiensis and An. quadriannulatus feeding on cattle in Zimbabwe. Medical & Veterinary Entomology 16: 207-213. Torr, S. J. (1994) Responses of tsetse flies (Diptera: Glossinidae) to warthog (Phacochoerus aethiopicus Pallas). Bull. Ent. Res. 84: 411-419. Torr, S. J. & Mangwiro, T. N. C. (2000) Interactions between cattle and biting flies: effects on the feeding rate of tsetse. Medical & Veterinary Entomology 14: 400-409. Vale, G. A. (1977) Feeding responses of tsetse flies (Diptera: Glossinindae) to stationary hosts. Bull. Ent. Res. 67: 635-649.