Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E90
Höfundar / Authors: Stefán Ó. Steingrímsson (1), Gabrielle M.V. Ladurée (1), Laura K. Weir (2), David Benhaïm (1), James. W.A. Grant (3)
Starfsvettvangur / Affiliations: 1. Hólar University, Iceland, 2. Saint Mary's University, Canada, 3. Concordia University, Canada.
Kynnir / Presenter: Stefán Óli Steingrímsson
Plasticity can shape individual fitness and the ability of populations to respond to ecological changes. This is particularly important for behaviors such as space use, social behavior and feeding activity, which directly affect how individuals use, compete for and share resources. However, limited knowledge exists on the consistency of these behaviors in stream fish, where individual observations are challenging. In a field experiment, we made repeated individual observations of territory size, feeding activity and social behavior of juvenile Arctic charr (Salvelinus alpinus). The study fish were individually tagged, placed in 12 stream enclosures (8 fish/enclosure) with different predation risk (one vs. five shelters) where conditions were stable (either high or low risk throughout the experiment) or unstable in time (fish exposed repeatedly to both low and high risk). Although juvenile Arctic charr used similar size areas under both stable predation risk treatments, they spent more time feeding and were in closer proximity when shelters were limited. In the unstable treatments, Arctic charr were plastic and modified their behaviors rapidly to altered shelter availability. Finally, Arctic charr grew fastest where shelters were limited throughout the experiments, perhaps because of increased feeding activity. This study improves our ability to predict how behavioral plasticity mediates growth and survival of stream fish in response to natural and human induced changes.