Bird Song: Steroid Hormones and Plasticity


In many species of birds, males sing to court females and to defend territories or nest sites, whereas females sing little, if at all. This behavioural sex difference is paralleled by sexual dimorphisms in neural and peripheral structures involved in song production. In adulthood, singing is generally activated by gonadal steroids, such as testosterone, but the role that these hormones play in the natural development of the structural and functional sex differences is at present an intriguing mystery.

Keywords: zebra finch; oestrogen; canary; aromatase; sex difference

Figure 1.

Sonogram (presented as frequency across time) of a vocal pattern produced by an adult male zebra finch. This song bout consists of an introductory note (i) followed by two repetitions of a series of syllables (a–f).

Figure 2.

Primary brain nuclei involved in song production and song learning. The motor pathway consists of regions connected with orange arrows. The regions connected with blue arrows are involved in the learning process.

Figure 3.

RA in an adult male and adult female zebra finch. The brain region of interest is highlighted with an arrow in each photograph, which depicts brain sections cut at 30‐μm and labelled with the Nissl stain thionin. Magnification of both pictures is the same (30×). The layered structure on the right edge of each photograph is the cerebellum, a brain region involved in the control of movement.



Alvarez‐Buylla A and Kirn JR (1997) Birth, migration, incorporation, and death of vocal control neurons in adult songbirds. Journal of Neurobiology 33: 585–601.

Arnold AP (1997) Sexual differentiation of the zebra finch song system: positive evidence, negative evidence, null hypotheses, and a paradigm shift. Journal of Neurobiology 33: 572–584.

Arnold AP and Schlinger BA (1993) Sexual differentiation of brain and behavior: the zebra finch is not just a flying rat. Brain, Behavior and Evolution 42: 231–241.

Bottjer SW and Arnold AP (1997) Developmental plasticity in neural circuits for a learned behavior. Annual Review of Neuroscience 20: 459–481.

Bottjer SW and Johnson F (1997) Circuits, hormones, and learning: vocal behavior in songbirds. Journal of Neurobiology 33: 602–618.

Brenowitz EA (1997) Comparative approaches to the avian song system. Journal of Neurobiology 33: 517–531.

Brenowitz EA, Margoliash D and Nordeen KW (1997) An introduction to birdsong and the avian song system. Journal of Neurobiology 33: 495–500.

Clayton DF (1997) Role of gene regulation in song circuit development and song learning. Journal of Neurobiology 33: 549–571.

Holloway CC and Clayton DF (2001) Estrogen synthesis in the male brain triggers development of the avian song control pathway in vitro. Nature Neuroscience 4: 170–175.

Kirn JR and De Voogd TJ (1989) Genesis and death of vocal control neurons during sexual differentiation in the zebra finch. Journal of Neuroscience 9: 3176–3187.

Konishi M and Akutagawa E (1985) Neuronal growth, atrophy and death in a sexually dimorphic song nucleus in the zebra finch brain. Nature 315: 145–147.

Margoliash D (1997) Functional organization of forebrain pathways for song production and perception. Journal of Neurobiology 33: 671–693.

Nottebohm F and Arnold AP (1976) Sexual dimorphism in vocal control areas of the songbird brain. Science 194: 211–213.

Schlinger BA (1997) Sex steroids and their actions on the birdsong system. Journal of Neurobiology 33: 619–631.

Springer ML and Wade J (1997) The effects of testicular tissue and prehatching inhibition of estrogen synthesis on the development of courtship and copulatory behavior in zebra finches. Hormones and Behavior 32: 46–59.

Further Reading

Arnold AP, Wade J, Grisham W, Jacobs E and Campagnoni AT (1996) Sexual differentiation of the brain in songbirds. Developmental Neuroscience 18: 124–136.

Bottjer SW (1997) Building a bird brain: sculpting neural circuits for a learned behavior. BioEssays 19: 1109–1116.

Harvey S and Etches RJ (1997) Perspectives in Avian Endocrinology. Bristol: Journal of Endocrinology Ltd.

Nelson RJ (1995) An Introduction to Behavioral Endocrinology. Sunderland, MA: Sinauer.

Nordeen EJ and Nordeen KW (1990) Neurogenesis and sensitive periods in avian song learning. Trends in Neurosciences 13: 31–36.

Short RV and Balaban E (1994) The Differences Between the Sexes. Cambridge, UK: Cambridge University Press.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Wade, Juli(Sep 2005) Bird Song: Steroid Hormones and Plasticity. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0004042]