The Journal of Threatened Taxa (JoTT) is dedicated to building evidence for conservaton globally by publishing peer-reviewed artcles OPEN ACCESS online every month at a reasonably rapid rate at www.threatenedtaxa.org. All artcles published in JoTT are registered under Creatve Commons Atributon 4.0 Internatonal License unless otherwise mentoned. JoTT allows unrestricted use, reproducton, and distributon of artcles in any medium by providing adequate credit to the author(s) and the source of publicaton. Journal of Threatened Taxa Building evidence for conservaton globally www.threatenedtaxa.org ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) Note Do predatory adult odonates estimate their adult prey odonates’ body size and dispersal ability to proceed with a successful attack? Tharaka Sudesh Priyadarshana 26 June 2021 | Vol. 13 | No. 7 | Pages: 18949–18952 DOI: 10.11609/jot.7198.13.7.18949-18952 For Focus, Scope, Aims, and Policies, visit htps://threatenedtaxa.org/index.php/JoTT/aims_scope For Artcle Submission Guidelines, visit htps://threatenedtaxa.org/index.php/JoTT/about/submissions For Policies against Scientfc Misconduct, visit htps://threatenedtaxa.org/index.php/JoTT/policies_various For reprints, contact <[email protected]> The opinions expressed by the authors do not refect the views of the Journal of Threatened Taxa, Wildlife Informaton Liaison Development Society, Zoo Outreach Organizaton, or any of the partners. The journal, the publisher, the host, and the part- Publisher & Host ners are not responsible for the accuracy of the politcal boundaries shown in the maps by the authors. Threatened Taxa Journal of Threatened Taxa | www.threatenedtaxa.org | 26 June 2021 | 13(7): 18949–18952 ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) OPEN ACCESS htps://doi.org/10.11609/jot.7198.13.7.18949-18952 #7198 | Received 07 December 2020 | Final received 03 April 2021 | Finally accepted 09 June 2021 NOTE Do predatory adult odonates estmate their adult prey odonates’ body size and dispersal ability to proceed with a successful atack? Tharaka Sudesh Priyadarshana Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore. [email protected], [email protected] The average body size and dispersal ability of a www.facebook.com/groups/dragonfyindia) FB group species signifcantly depends on its taxonomic order between 2020 to 2016 and posts of the “Dragonfy (Siemann et al. 1999). Indeed, there are signifcant body Interest Group of Sri Lanka” (htps://www.facebook. size and dispersal ability diferences between predatory com/groups/256874097746055) FB group between odonates and their typical prey items such as gnats, 2020 to 2012. I also searched the “Odonata of India” mayfies, fies, mosquitoes, and other small-sized fying (htps://www.indianodonata.org/) website for more insects. During one of my feld visits in Sri Lanka in 2015, potental records. For most of those records, predator I observed an adult dragonfy (Orthetrum sabina) eatng and prey species had been identfed by experts within another species of dragonfy (O. luzonicum) (Image ­­1), those groups. Prey odonates that could not be identfed and their average body sizes and dispersal abilites were to species level due to predaton were excluded from the similar. Similar observatons were being circulated on fnal dataset. The records of mature predators preying Odonate-specialists’ Facebook (FB) groups, suggestng upon juveniles were also excluded because that might that adult odonates feed on other species of odonates result in some biases in the dataset as those individuals or even the same species (see Image 2). When predators are immature. The fnal dataset included 67 records of prey upon members of the same taxonomic group, it is adult predatory and prey odonate encounters from Sri difcult to predict whether the predators stll estmate Lanka (24) and India (43) — nine species of predators the size and dispersal ability of their potental prey and 27 species of prey (see Table 1). items to proceed with a successful atack (Woodward & Morphometric trait measurement data related Hildrew 2002). This, however, can be measured by using to body size and dispersal ability for each predator a robust statstcal analysis and a precise dataset. and prey odonate was extracted from the “Odonate Even though adult odonates feed upon adult Phenotypic Database” (OPD) at htp://www. odonates, such records are uncommon. To build the odonatephenotypicdatabase.org/ (Waller et al. 2019). dataset, I surveyed two private FB specialists’ groups When the data was not available in the OPD (only for for such potental records. I manually checked every eight species), the data was extracted from other single post of the “DragonfySouthAsia” (htps:// published literature (see the Supplementary data for Editor: Anonymity requested. Date of publicaton: 26 June 2021 (online & print) Citaton: Priyadarshana, T.S. (2021). Do predatory adult odonates estmate their adult prey odonates’ body size and dispersal ability to proceed with a successful atack? Journal of Threatened Taxa 13(7): 18949–18952. htps://doi.org/10.11609/jot.7198.13.7.18949-18952 Copyright: © Priyadarshana 2021. Creatve Commons Atributon 4.0 Internatonal License. JoTT allows unrestricted use, reproducton, and distributon of this artcle in any medium by providing adequate credit to the author(s) and the source of publicaton. Funding: Self-funded. Competng interests: The author declares no competng interests. Acknowledgements: I thank all those who shared their records and identfed predatory and prey odonate species through cyberspace, Christos Mammides for his comments on the frst draf, and Subramaniam Gopalakrishnan for the Image 2. 18949 J TT Predatory adult odonates and their adult prey odonates Priyadarshana Table 1. Records of adult predator and prey odonate encounters from Sri Lanka (24) and India (43) from 2012 to 2020. Please see the supplementary data for additonal informaton and references. Record Predator odonate Record Predator odonate Country Prey odonate species Country Prey odonate species number species number species Records of Anisoptera (dragonfies) preying upon Anisoptera (n= 40) 39 India Orthetrum sabina Orthetrum sabina Paragomphus 1 Sri Lanka Orthetrum sabina Neurothemis tullia 40 India Orthetrum sabina lineatus 2 Sri Lanka Orthetrum sabina Neurothemis tullia Records of Anisoptera (dragonfies) preying upon Zygoptera (damselfies) 3 Sri Lanka Orthetrum sabina Diplacodes trivialis (n= 16) Pseudagrion Orthetrum sabina Orthetrum pruinosum 41 Sri Lanka Orthetrum sabina 4 Sri Lanka microcephalum Brachythemis Ceriagrion 5 Sri Lanka Ictnogomphus rapax 42 Sri Lanka Acisoma panorpoides contaminata coromandelianum Brachythemis Pseudagrion 6 Sri Lanka Orthetrum sabina 43 Sri Lanka Orthetrum sabina contaminata rubriceps 7 Sri Lanka Orthetrum sabina Orthetrum luzonicum Pseudagrion 44 Sri Lanka Orthetrum sabina microcephalum 8 Sri Lanka Orthetrum sabina Neurothemis tullia Ceriagrion 45 Sri Lanka Orthetrum sabina 9 Sri Lanka Orthetrum sabina Orthetrum luzonicum coromandelianum Brachythemis Brachythemis Pseudagrion 10 Sri Lanka Orthetrum sabina 46 Sri Lanka contaminata contaminata rubriceps 11 Sri Lanka Orthetrum sabina Orthetrum luzonicum 47 India Orthetrum sabina Onychargia atrocyana 12 Sri Lanka Orthetrum sabina Orthetrum pruinosum 48 India Orthetrum sabina Lestes viridulus 13 India Orthetrum sabina Neurothemis fulvia 49 India Orthetrum sabina Ischnura rubilio Tetrathemis 50 India Orthetrum sabina Ischnura rubilio 14 India Orthetrum sabina platyptera Ceriagrion 51 India Acisoma panorpoides 15 India Orthetrum sabina Diplacodes trivialis coromandelianum Agriocnemis 16 India Orthetrum sabina Potamarcha congener 52 India Acisoma panorpoides splendidissima 17 India Orthetrum sabina Diplacodes trivialis Brachythemis 53 India Ischnura senegalensis contaminata 18 India Orthetrum sabina Orthetrum sabina Brachythemis 54 India Ischnura senegalensis 19 India Orthetrum sabina Diplacodes trivialis contaminata 20 India Orthetrum sabina Diplacodes trivialis 55 India Orthetrum sabina Ischnura senegalensis Agriocnemis 21 India Orthetrum sabina Orthetrum sabina 56 India Orthetrum sabina pygmaea 22 India Orthetrum sabina Orthetrum pruinosum Records of Zygoptera (damselfies) preying upon Zygoptera (n= 11) 23 India Rhodothemis rufa Neurothemis tullia Ceriagrion Ceriagrion 57 Sri Lanka 24 India Orthetrum sabina Rhyothemis variegata cerinorubellum coromandelianum Ceriagrion Agriocnemis 58 Sri Lanka 25 India Orthetrum sabina Orthetrum pruinosum coromandelianum pygmaea Ceriagrion 26 India Orthetrum sabina Potamarcha congener 59 Sri Lanka Onychargia atrocyana coromandelianum 27 India Orthetrum sabina Diplacodes trivialis Agriocnemis 60 Sri Lanka Ischnura senegalensis 28 India Orthetrum sabina Orthetrum sabina pygmaea Ceriagrion Pseudagrion 61 Sri Lanka 29 India Orthetrum sabina Orthetrum sabina coromandelianum microcephalum 30 India Orthetrum sabina Crocothemis servilia Agriocnemis 62 Sri Lanka Ischnura senegalensis pygmaea 31 India Orthetrum sabina Trithemis aurora Ceriagrion Ceriagrion 63 India 32 India Orthetrum sabina Pantala favescenes coromandelianum cerinorubellum Ceriagrion Ceriagrion 33 India Orthetrum sabina Potamarcha congener 64 India coromandelianum cerinorubellum 34 India Orthetrum sabina Diplacodes trivialis Agriocnemis 65 India Ischnura senegalensis pygmaea 35 India Orthetrum sabina Pantala favescenes Ceriagrion 66 India Ischnura senegalensis 36 India Orthetrum sabina Trithemis aurora