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This chapter assesses the influence of photoperiod as a mechanism for regulating annual cycles. In particular, the interactive influence of changing light levels on regulating the annual hormone cycles that influence the development of gonads (breeding regulation) and neural structures associated with both food caching and song control is reviewed. The focus is on photoperiodism and seasonality in Parids, citing recent studies of black-capped chickadees. These studies include studies on the effects of photoperiod on reproduction, on singing and the neural system controlling song, and on food-storing and the hippocampus. Recent studies have revealed that black-capped chickadees exhibit photoperiodic responses and photorefractoriness similar to many other songbird species. However, seasonal changes in the brain have produced mixed results, especially when comparing birds caught from the wild with birds held in captivity.

This chapter examines the naturally- and sexually-selected consequences of social rank in a population of black-capped chickadees studied for over a decade in eastern Ontario, Canada. The discussion begins with a review of what is known about the characteristics that distinguish individuals attaining high social rank from subordinates. Aspects of status signaling, such as song and plumage features, as well as rank-related differences in survival and annual reproductive success, are explored. Using extensive observations of interactions among color-banded individuals, the process by which dominance hierarchies are maintained is described. The effects of individual variation in rank acquisition on lifetime reproductive success (LRS) are then addressed. Analysis of LRS was used to compare how the overall genetic contribution of individuals is affected by both lifespan and reproductive strategies. Breeding lifespan has been identified as the most important predictor of LRS in mammals and birds; nevertheless the interaction between social rank and LRS may also be significant and warrants investigation.

This chapter summarizes investigations of a common vocalization in the repertoire of the black-capped chickadee. This vocalization, known as the gargle call, has an ontogeny that is dependent upon learning occurring from early life through adulthood. As is the case for the territorial songs of a great many species of songbirds, social interactions most likely play a significant role in gargle call ontogeny. Thus, these calls evidently result from ‘socially biased individual learning,’ simply termed ‘social learning’ in this chapter. In examining the gargle call, this chapter gives a brief description of the call, provides information on the ontogeny of the call as it occurs in natural populations, and describes the fundamental features of the call, the nature and extent of sharing of calls by birds in a local area, and the similarities and changes in calls across time. Furthermore, observational and experimental evidence on the roles of the calls in the social lives of the birds is reported, and inferences are drawn about the ways social behaviour selects based on vocal convergence among birds in a local area, and the possible functional significance of convergence.