Social context affects behavioral responsiveness to maternal alarm calls in Bobwhite quail chicks

Abstract

These studies examined the effects of altered developmental experience (rearing history) and altered behavioral context (testing environment) on the alarm call responsiveness of maternally naive, incubator-reared bobwhite quail chicks. Experiment 1 assessed alarm call responsiveness in socially-reared, socially-tested hatchlings across the first 96 hours following hatch. No significant age effects were revealed. Hatchlings tested at 24 hours did not differ significantly from birds tested at 48, 72, or 96 hours on the two principle behavioral measures (number of grid crossings and vocalizations per one-minute trials).

Experiment 2 assessed whether hatchlings' alarm call responsiveness is at least partially dependent on the availability of cover (i.e., hiding sites) in the testing situation. No significant differences in responding were found in comparisons between hiding sites and social (non-hiding sites) testing conditions. However, behavioral observations did indicate that hatchlings in the hiding site condition utilized the hiding site as an attractor, in that chicks typically huddled and froze around the hiding site structure.

Experiment 3 examined the relative effects of individual testing on socially-reared bobwhite quail hatchlings. Results revealed that individually tested hatchlings increased their locomotor activity following initial exposure to the maternal alarm call when compared to socially tested chicks. Vocalizations were significantly reduced in post-alarm call testing from pre-alarm call levels. However, hatchlings tested individually had higher levels of vocal activity when compared to socially tested chicks. In comparison with socially-reared/socially-tested subjects, socially-reared/individually tested subjects were more active following exposure to the maternal alarm call than they were prior to exposure to the call.

Results from the three experiments are discussed in terms of species-typical experience and development. It is maintained that species-typical responding to the bobwhite maternal alarm call is partially influenced by social context. An argument for continued polythetic research on behavioral development in avian communication is also made.