Niche partitioning at emergence of two sympatric top-predator dragonflies,Anax imperator and A. parthenope (Odonata: Aeshnidae) |
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Authors: | Nedjwa Boucenna Amin Kahalerras Nabila Boukhemza-Zemmouri Moussa Houhamdi |
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Institution: | 1. Department of Biology, Faculty of Biological and Agricultural Sciences, University of Tizi Ouzou, Tizi Ouzou 15000, Algeria;2. Department of Nature and Life Sciences, Faculty of Nature and Life Sciences and Earth and Universe Sciences, University of 8 May 1945, Guelma 24000, Algeria |
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Abstract: | In natural communities, closely related species are phenotypically similar but usually spatially and/or temporally isolated. In odonates, interspecific competition occurs not only at the larval or adult stage but also during emergence. We investigated the emergence of two sympatric Anax species, focusing on the temporal pattern, vertical stratification, and body size trend over time. Anax imperator started to emerge two weeks earlier than A. parthenope but most of the emergence season overlapped. Both species showed an asynchronous emergence and the median emergence date was 10.3 days earlier in A. imperator. Sex ratio at emergence was not significantly different from 1:1. Body size of both species increased significantly over time, which contrasts many previous studies. The height of exuvia fixation was not significantly different between species but the larger species A. parthenope selected longer supports. |
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Keywords: | Competition congenerics exuvia site selection North Africa |
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