@article{fdi:010063091,
  title = {{L}ocal enhancement in a seabird : reaction distances and foraging consequence of predator aggregations},
  author = {{T}hiebault, {A}. and {M}ullers, {R}. {H}. {E}. and {P}istorius, {P}. {A}. and {T}remblay, {Y}ann},
  editor = {},
  language = {{ENG}},
  abstract = {{S}eabirds foraging on pelagic fish develop behavioral strategies specifically adapted to locate inconspicuous prey that are aggregated in spatially dynamic patches. {I}n the marine environment, they may use various mechanisms to detect cues of prey availability. {T}he aggregation of predators at a patch of food is a particularly obvious cue to locate prey, a mechanism known as local enhancement. {P}ioneering studies described the formation of foraging groups at sea, showing that seabirds are attracted to feeding conspecifics. {I}mproved foraging success due to local enhancement has been suggested from modeling studies, but no direct validation of these results exists. {W}e deployed video cameras concomitantly with {GPS} loggers on {C}ape gannets to study the behavioral responses of equipped birds to the aggregation of predators at food patches. {W}e showed that the reaction distances of equipped birds increased with the size of an aggregation, demonstrating that predator aggregations enhance food detectability for foragers. {F}or small aggregations (< 50 gannets), reaction distances were mostly less than 10 km, and they increased up to almost 40 km for larger aggregations (100-150 gannets). {I}n addition, we showed that the number and frequency of dives increased with the number of conspecifics aggregated, up to a threshold. {T}he predator aggregations on a patch of food could, therefore, not only inform about the presence of prey but also entail information about foraging conditions. {F}rom direct observations on the various components involved, our study provides justification of the use and advantages of local enhancement in foraging seabirds.{T}o locate inconspicuous and ephemeral fish schools in the ocean, seabirds may use indirect cues such as feeding conspecifics. {B}ased on video cameras and {GPS} loggers concomitantly attached to {C}ape gannets, we showed that predator aggregations on a patch of food enhanced prey detectability. {G}annets reacted to join a group of 50 feeding conspecifics from similar to 10 km, whereas a group of 100-150 gannets triggered a reaction from up to 40 km.},
  keywords = {camera ; foraging cues ; gannet ; {GPS} ; group hunting ; network foraging ; prey detection ; social information ; {AFRIQUE} {DU} {SUD}},
  booktitle = {},
  journal = {{B}ehavioral {E}cology},
  volume = {25},
  numero = {6},
  pages = {1302--1310},
  ISSN = {1045-2249},
  year = {2014},
  DOI = {10.1093/beheco/aru132},
  URL = {https://www.documentation.ird.fr/hor/fdi:010063091},
}