Open this publication in new window or tab >>Show others...
2023 (English)In: Fishes, E-ISSN 2410-3888, Vol. 8, no 10, article id 521Article in journal (Other academic) Published
Abstract [en]
During winter, stream fishes are vulnerable to semi-aquatic predators like mammals and birds and reduce encounters by being active in darkness or under surface ice. Less is known about the behavior of fishes towards instream piscivorous fishes. Here, we examined how surface ice and light affected the anti-predator behavior of juvenile brown trout (Salmo trutta Linnaeus, 1758) in relation to piscivorous burbot (Lota lota Linnaeus, 1758) and northern pike (Esox lucius Linnaeus, 1758) at 4 degrees C in experimental flumes. Trout had lower foraging and swimming activity and spent more time sheltering when predators were present than when absent. In daylight, trout's swimming activity was not affected by predators, whereas in darkness trout were less active when predators were present. Trout consumed more drifting prey during the day when ice was present, and they positioned themselves further upstream when under ice cover, regardless of light conditions. Trout stayed closer to conspecifics under ice, but only in the presence of pike. Piscivorous fishes thus constitute an essential part of the predatory landscape of juvenile trout in winter, and thus loss of ice cover caused by climate warming will likely affect trout's interactions with predators.
Keywords
anti-predator, global changer, diel behavior, foraging, piscivores, predators
National Category
Ecology Zoology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-88204 (URN)10.3390/fishes8100521 (DOI)001089943500001 ()2-s2.0-85175046960 (Scopus ID)
Funder
Karlstad University
Note
This paper was included as a manuscript in doctoral thesis entitled "Early life stages of brown trout - Anti-predator responses under warming winters" 2022:2
2022-01-262022-01-262023-11-28Bibliographically approved