Mahdjoub H. & al. 2023
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Demoiselles et Libellules du Monde entier
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 14 552 articles
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Mahdjoub H. & al. 2023 - Condition‑dependent survival and movement behavior in an endangered endemic damselfy. - Scientific reports, 13 : 21819. - PDF LINK
Auteurs : Mahdjoub H., Zebsa R., Kahalerras A., Amai H., Bensouilah S., Samways M.J. & Khelifa R.
Abstract
Movement is essential for the maintenance of populations in their natural habitats, particularly for threatened species living in fuctuating environments. Empirical evidence suggests that the probability and distance of movement in territorial species are context-dependent, often depending on population density and sex. Here, we investigate the movement behavior of the spring cohort of an endangered endemic damselfy Calopteryx exul in a lotic habitat of Northeast Algeria using capturemark-recapture (CMR) of adults. By sampling 10 gridded river stretches across a 2 km section of the watercourse, we were able to estimate the distance of movement throughout individual lifespans and estimate movement probability for both males and females. We used multistate models to examine whether individual density and sex ratio infuence survival and movement probability. We found that males and females had similar movement kernels with most individuals moving short distances (83% performing movements of < 100 m and only 1%> 1000 m). Of the 547 marked individuals, 63% were residents, and 37% were movers (moved at least 50 m from one sampling occasion to another). Survival probability showed higher estimates for females and was slightly density-dependent (i.e., lower survival probabilities were associated with high male densities). Survival probability did not show a marked diference between residents and movers. Movement probability and distances were positively correlated with individual density, but were not or slightly correlated with sex ratio, respectively. These results are not in line with the hypotheses of sex-biased movement and survival costs of movement. Our results suggest that the species performs mostly short-distance movements that are dependent on intraspecifc interactions.
