Effects of temperature and browning on the functional response of a freshwater top predator
(2026) In Journal of Animal Ecology 95(5). p.824-836- Abstract
Freshwater lakes are becoming warmer and browner, with poorly known ecosystem consequences. A major unresolved issue is how these changes will affect the feeding rates of predators that regulate top-down trophic cascades. We explored the effects of temperature and browning on the functional response and feeding rates of a keystone predator, the Northern pike Esox lucius. We first derived a simple mechanistic model on the effect of temperature and browning on predator feeding rates. To test predictions from the model, we performed two laboratory experiments where we estimated pike functional responses in brown and clear water at three temperatures and quantified feeding rates along a gradient from completely clear to extremely brown. We... (More)
Freshwater lakes are becoming warmer and browner, with poorly known ecosystem consequences. A major unresolved issue is how these changes will affect the feeding rates of predators that regulate top-down trophic cascades. We explored the effects of temperature and browning on the functional response and feeding rates of a keystone predator, the Northern pike Esox lucius. We first derived a simple mechanistic model on the effect of temperature and browning on predator feeding rates. To test predictions from the model, we performed two laboratory experiments where we estimated pike functional responses in brown and clear water at three temperatures and quantified feeding rates along a gradient from completely clear to extremely brown. We find strikingly weak effects of temperature and browning on pike feeding rates, even under extreme levels of browning. Pike showed an asymptotic Type II functional response under most conditions but switched to a dome-shaped Type IV functional response in cold clear water, possibly due to seasonal changes in the schooling behaviour of prey. Our results suggest that temperature and browning may have interactive effects on predator functional responses mediated via changes in prey behaviour and support the view that browning affects piscivorous fish mainly through bottom-up effects rather than changes in foraging efficiency.
(Less)
- author
- Nilsson-Örtman, Viktor LU ; Nilsson, Erik LU and Brönmark, Christer LU
- organization
- publishing date
- 2026
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- browning, climate change, functional responses, predation, temperature, trophic cascades, visual conditions
- in
- Journal of Animal Ecology
- volume
- 95
- issue
- 5
- pages
- 824 - 836
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:41840780
- scopus:105033053406
- ISSN
- 0021-8790
- DOI
- 10.1111/1365-2656.70233
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 The Author(s). Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.
- id
- 47f00f11-9ae0-4ef0-a7a4-92e18ac85ad8
- date added to LUP
- 2026-04-28 17:01:50
- date last changed
- 2026-06-10 09:12:38
@article{47f00f11-9ae0-4ef0-a7a4-92e18ac85ad8,
abstract = {{<p>Freshwater lakes are becoming warmer and browner, with poorly known ecosystem consequences. A major unresolved issue is how these changes will affect the feeding rates of predators that regulate top-down trophic cascades. We explored the effects of temperature and browning on the functional response and feeding rates of a keystone predator, the Northern pike Esox lucius. We first derived a simple mechanistic model on the effect of temperature and browning on predator feeding rates. To test predictions from the model, we performed two laboratory experiments where we estimated pike functional responses in brown and clear water at three temperatures and quantified feeding rates along a gradient from completely clear to extremely brown. We find strikingly weak effects of temperature and browning on pike feeding rates, even under extreme levels of browning. Pike showed an asymptotic Type II functional response under most conditions but switched to a dome-shaped Type IV functional response in cold clear water, possibly due to seasonal changes in the schooling behaviour of prey. Our results suggest that temperature and browning may have interactive effects on predator functional responses mediated via changes in prey behaviour and support the view that browning affects piscivorous fish mainly through bottom-up effects rather than changes in foraging efficiency.</p>}},
author = {{Nilsson-Örtman, Viktor and Nilsson, Erik and Brönmark, Christer}},
issn = {{0021-8790}},
keywords = {{browning; climate change; functional responses; predation; temperature; trophic cascades; visual conditions}},
language = {{eng}},
number = {{5}},
pages = {{824--836}},
publisher = {{Wiley-Blackwell}},
series = {{Journal of Animal Ecology}},
title = {{Effects of temperature and browning on the functional response of a freshwater top predator}},
url = {{http://dx.doi.org/10.1111/1365-2656.70233}},
doi = {{10.1111/1365-2656.70233}},
volume = {{95}},
year = {{2026}},
}