Data from: Density-dependent diel activity in stream-dwelling Arctic charr Salvelinus alpinus

• Main Authors: Fingerle, Amy, Larranaga, Nicolas, Steingrímsson, Stefán Óli
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2017
• Subjects: salmonidae; activity rate; Arctic charr; temporal segregation; diel activity; Resource partitioning; Salvelinus alpinus; Holocene; Arctic char
• Online Access: https://doi.org/10.5061/dryad.bn46h

Intraspecific competition plays a significant role in shaping how animals use and share habitats in space and time. However, the way individuals may modify their diel activity in response to increased competition has received limited attention. We used juvenile (age 1+) Arctic charr Salvelinus alpinus to test the prediction that individuals at high population density are more active and distribute their foraging activity over a greater portion of the 24-h cycle than individuals at low population density. Individually tagged fish were stocked in seminatural stream enclosures at low (2 fish/m2) and high (6 fish/m2) density. During each of two 2-week experimental rounds, activity of all fish within each enclosure was recorded every 3 h over seven 24-h cycles. At high density, fish were more active and distributed their activity over a greater portion of the 24-h cycle, with increased activity particularly at crepuscular times. Fluctuations in ecological conditions (e.g., water temperature and light intensity) also affected activity. Fish at high density grew as fast as fish at low density. This study demonstrates that individuals exhibit a degree of behavioral flexibility in their response to changes in ecological conditions and suggests that intraspecific competition can cause animals to modify temporal aspects of their activity to gain access to resources and maintain growth. Invertebrate drift Data collected in the field in 2013. Please see ReadMe file for a description of column headings. Drift_data.csv Activity of individual fish Data collected in the field in 2013. Please see ReadMe file for a description of column headings. Fish_data.csv Enclosure scans Data collected in the field in 2013. Please see ReadMe file for a description of column headings. Scan_data.csv Substrate estimations Data collected in the field in 2013. Please see ReadMe file for a description of column headings. Substrate_data.csv Water current velocity measurements Data collected in the field in 2013. Please see ReadMe file for a ...