Behavioral predictors of outdoor range use in slow-growing naked-neck male broiler chickens: The role of social context
Abstract
This study investigated whether behavioral traits measured before outdoor range access could predict subsequent range use in slow-growing naked-neck male broilers and whether social context modulates the expression of these traits. Across two successive flocks (n = 220 birds per flock), individuals were assessed using three complementary tests: a judgement bias test, an open field test conducted both in isolation and in trios, and an attention bias test performed after range access under both isolation and paired conditions. Individual range use was measured using an index based on repeated scans that recorded how frequently and how far each bird used the outdoor range. Principal component analysis of behaviors recorded during the open field test before range access identified two main axes: activity–exploration and fearfulness–vigilance. Activity–exploration scores positively predicted subsequent range use, whereas fearfulness-related behaviors did not. Birds tested in trios were more exploratory/active and less vigilant than when tested alone, indicating strong social modulation of behavior. After range access, behavioral differences between high- and low-rangers became particularly evident under social conditions: high-rangers maintained stable activity levels across contexts, whereas low-rangers showed reduced activity in trios. Neither approach responses in the judgement bias test nor reactions to the alarm call in the attention bias test were associated with range use. However, atypical response patterns and limited responsiveness to the test stimuli likely reduced the sensitivity of these tests. Social context reduced the probability of reacting to the alarm call during the attention bias test, consistent with a possible social buffering effect. Overall, early exploratory tendencies predicted subsequent outdoor range use in slow-growing broilers. We discuss the importance of assessing behavioral traits in ecologically relevant social contexts and of further validating affect-driven cognitive bias assessments for broiler chickens, given the methodological challenges that still remain.
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BibTeX
@article{germain2026behavioral,
title = {{Behavioral predictors of outdoor range use in slow-growing naked-neck male broiler chickens: The role of social context}},
author = {Caroline Germain and Vanessa Guesdon and Ludovic Calandreau and Karine Germain and Vitor Hugo Bessa Ferreira},
journal = {Applied Animal Behaviour Science},
year = {2026},
month = aug,
doi = {10.1016/j.applanim.2026.107161},
url = {https://hal.inrae.fr/hal-05740731v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Behavioral predictors of outdoor range use in slow-growing naked-neck male broiler chickens: The role of social context
AU - Caroline Germain
AU - Vanessa Guesdon
AU - Ludovic Calandreau
AU - Karine Germain
AU - Vitor Hugo Bessa Ferreira
PY - 2026
DA - 2026/08/21
JO - Applied Animal Behaviour Science
DO - 10.1016/j.applanim.2026.107161
UR - https://hal.inrae.fr/hal-05740731v1
AB - This study investigated whether behavioral traits measured before outdoor range access could predict subsequent range use in slow-growing naked-neck male broilers and whether social context modulates the expression of these traits. Across two successive flocks (n = 220 birds per flock), individuals were assessed using three complementary tests: a judgement bias test, an open field test conducted both in isolation and in trios, and an attention bias test performed after range access under both isolation and paired conditions. Individual range use was measured using an index based on repeated scans that recorded how frequently and how far each bird used the outdoor range. Principal component analysis of behaviors recorded during the open field test before range access identified two main axes: activity–exploration and fearfulness–vigilance. Activity–exploration scores positively predicted subsequent range use, whereas fearfulness-related behaviors did not. Birds tested in trios were more exploratory/active and less vigilant than when tested alone, indicating strong social modulation of behavior. After range access, behavioral differences between high- and low-rangers became particularly evident under social conditions: high-rangers maintained stable activity levels across contexts, whereas low-rangers showed reduced activity in trios. Neither approach responses in the judgement bias test nor reactions to the alarm call in the attention bias test were associated with range use. However, atypical response patterns and limited responsiveness to the test stimuli likely reduced the sensitivity of these tests. Social context reduced the probability of reacting to the alarm call during the attention bias test, consistent with a possible social buffering effect. Overall, early exploratory tendencies predicted subsequent outdoor range use in slow-growing broilers. We discuss the importance of assessing behavioral traits in ecologically relevant social contexts and of further validating affect-driven cognitive bias assessments for broiler chickens, given the methodological challenges that still remain.
SN - 0168-1591
SN - 1872-9045
ER -