Testing for sentinel coordination in Smooth-billed Anis (Crotophaga ani)

Sentinel behaviour has been widely described, but whether or not it is coordinated among group members requires careful examination. The Smooth-billed Ani, Crotophaga ani , a joint-nesting cooperatively breeding bird, appears to have a sentinel system; however, it is unknown whether that vigilance i...

Full description

Saved in:
Bibliographic Details
Published in:Journal of ornithology 2019-01, Vol.160 (1), p.165-172
Main Authors: Hing, Jing Sheng, Schmaltz, Gregory, Quinn, James S.
Format: Article
Language:English
Subjects:
Biomedical and Life Sciences
Breeding seasons
Communal breeding
Crotophaga ani
Ecology
Fish & Wildlife Biology & Management
Hypotheses
Life Sciences
Original Article
Social behavior
Vigilance
Zoology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Sentinel behaviour has been widely described, but whether or not it is coordinated among group members requires careful examination. The Smooth-billed Ani, Crotophaga ani , a joint-nesting cooperatively breeding bird, appears to have a sentinel system; however, it is unknown whether that vigilance is coordinated, the defining feature of sentinel behaviour. We followed social groups during two breeding seasons to observe and time their individual sentinel bouts. We then tested for coordination by quantifying the observed and expected proportions of time during which (1) no sentinel was present during observations, and (2) two or more sentinels were present. The majority of social groups spent less time than expected, under the coordination hypothesis, with at least one sentinel, indicating evidence against coordinated vigilance. This was significant for social groups observed in 2015, but not in 2002. Across both years, temporal overlap in sentinel behaviour between two individuals occurred significantly less than expected under the coordination hypothesis. This study contributes to a gap in our knowledge of sentinel behaviour and suggests that Smooth-billed Anis lack organized vigilance, possibly due to low within-group relatedness and group instability.
ISSN:2193-7192
2193-7206
DOI:10.1007/s10336-018-1584-6