Effect of the density of conspecifics on runway social reinstatement behavior of male Japanese quail genetically selected for contrasting adrenocortical responsiveness to stress.

GUZMÁN, D. A.; SATTERLEE, D. G.; SCHMIDT, J. B.; KEMBRO, J. M.; MARÍN, R. H.

Niagara Falls, Ontario, Canada

Congreso; 2008 Poultry Science Association Annual Meeting; 2008

Poultry Science Association

Runway tests are considered indicative of underlying sociality in birds and their ability to make social discriminations and establish interactions among conspecifics placed in goal boxes at one or both ends of a runway. Herein, male social reinstatement behavior in juvenile Japanese quail selected for a reduced (LS, low stress) or exaggerated (HS, high stress) adrenocortical response to brief mechanical restraint was evaluated. During a 8 min test period, individual males were given the choice to reinstate with either 2 (low density, LD) or 8 (high density, HD) unfamiliar conspecifics placed in goal boxes at opposite ends of a double runway (DRW). Then, the same males were individually retested in a single goal box runway (SRW) wherein they were exposed, in separate tests, to either a goal box containing a LD or HD of unfamiliar males. Each of the SRW tests used a test ceiling of 6 min. In the DRW, a higher (P < 0.01) number of HS males started their ambulation towards the goal box containing a HD as opposed to LD of males. DRW tested HS males also spent more (P < 0.01) time in close proximity (within a 10 cm close zone; CZ) to the HD (218 s) rather than the LD (57 s) of conspecifics. In contrast, LS males did not differ in their initial direction of travel in the DRW and they spent similar amounts of times in the CZs of their stimulus LD (141 s) and HD (124 s) males. Similar to the DRW results, in the SRW, HS males spent more (P < 0.01) time in the CZ of HD rather than LD conspecifics while LS quail spent similar amounts of time in the CZs of LD and HD males. Considering that runways are novel (and therefore frightening) environments, the present findings suggest that HS quail may find better shelter (i.e., more comfort) in close proximity to a larger rather than smaller group of conspecifics while LS birds find groups of varying conspecific density equally attractive. The results suggest that LS quail possess favorable social adaptive qualities since they appear to be better suited to cope with situations were the density of conspecifics is variable.