Advanced

Predator-prey encounter rates in freshwater piscivores: effects of prey density and water transparency

Turesson, Håkan LU and Brönmark, Christer LU (2007) In Oecologia 153(2). p.281-290
Abstract
One of the most fundamental components of predator-prey models is encounter rate, modelled as the product of prey density and search efficiency. Encounter rates have, however, rarely been measured in empirical studies. In this study, we used a video system approach to estimate how encounter rates between piscivorous fish that use a sit-and-wait foraging strategy and their prey depend on prey density and environmental factors such as turbidity. We first manipulated prey density in a controlled pool and field enclosure experiments where environmental factors were held constant. In a correlative study of 15 freshwater lakes we then estimated encounter rates in natural habitats and related the results to both prey fish density and... (More)
One of the most fundamental components of predator-prey models is encounter rate, modelled as the product of prey density and search efficiency. Encounter rates have, however, rarely been measured in empirical studies. In this study, we used a video system approach to estimate how encounter rates between piscivorous fish that use a sit-and-wait foraging strategy and their prey depend on prey density and environmental factors such as turbidity. We first manipulated prey density in a controlled pool and field enclosure experiments where environmental factors were held constant. In a correlative study of 15 freshwater lakes we then estimated encounter rates in natural habitats and related the results to both prey fish density and environmental factors. We found the expected positive dependence of individual encounter rates on prey density in our pool and enclosure experiments, whereas the relation between school encounter rate and prey density was less clear. In the field survey, encounter rates did not correlate with prey density but instead correlated positively with water transparency. Water transparency decreases with increasing prey density along the productivity gradient and will reduce prey detection distance and thus predator search efficiency. Therefore, visual predator-prey encounter rates do not increase, and may even decrease, with increasing productivity despite increasing prey densities. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
encounter rate piscivore ambush forager, turbidity water colour
in
Oecologia
volume
153
issue
2
pages
281 - 290
publisher
Springer
external identifiers
  • wos:000249150200008
  • scopus:34547811378
ISSN
1432-1939
DOI
10.1007/s00442-007-0728-9
language
English
LU publication?
yes
id
2f29a3d7-7b09-4afb-8425-707d72439119 (old id 687675)
date added to LUP
2007-12-20 11:32:00
date last changed
2017-07-02 04:19:26
@article{2f29a3d7-7b09-4afb-8425-707d72439119,
  abstract     = {One of the most fundamental components of predator-prey models is encounter rate, modelled as the product of prey density and search efficiency. Encounter rates have, however, rarely been measured in empirical studies. In this study, we used a video system approach to estimate how encounter rates between piscivorous fish that use a sit-and-wait foraging strategy and their prey depend on prey density and environmental factors such as turbidity. We first manipulated prey density in a controlled pool and field enclosure experiments where environmental factors were held constant. In a correlative study of 15 freshwater lakes we then estimated encounter rates in natural habitats and related the results to both prey fish density and environmental factors. We found the expected positive dependence of individual encounter rates on prey density in our pool and enclosure experiments, whereas the relation between school encounter rate and prey density was less clear. In the field survey, encounter rates did not correlate with prey density but instead correlated positively with water transparency. Water transparency decreases with increasing prey density along the productivity gradient and will reduce prey detection distance and thus predator search efficiency. Therefore, visual predator-prey encounter rates do not increase, and may even decrease, with increasing productivity despite increasing prey densities.},
  author       = {Turesson, Håkan and Brönmark, Christer},
  issn         = {1432-1939},
  keyword      = {encounter rate piscivore ambush forager,turbidity water colour},
  language     = {eng},
  number       = {2},
  pages        = {281--290},
  publisher    = {Springer},
  series       = {Oecologia},
  title        = {Predator-prey encounter rates in freshwater piscivores: effects of prey density and water transparency},
  url          = {http://dx.doi.org/10.1007/s00442-007-0728-9},
  volume       = {153},
  year         = {2007},
}