Female birds that do not normally sing possess brain nuclei associated with song production in males. To determine whether one song nucleus, the caudal nucleus of the ventral hyperstriatum (HVc), acts in conspecific song perception, courtship responses of female canaries to canary and white-crowned sparrow songs were compared before and after HVc lesions. Bilateral lesions of a portion of the H...

Repertoire matching occurs when one songbird replies to another with a song type that the two birds share. Repertoire matching has previously been demonstrated to occur at well above chance levels in a western population of song sparrows, where it is hypothesized to serve as a low level threat in a hierarchy of aggressive signals. Here we test for repertoire matching in an eastern population of...

There is increased neuronal firing in the high vocal center (a motor nucleus) and other song nuclei of canaries, Serinus canaria, and zebra finches, Taeniopygia guttata, whenever these songbirds sing or hear song. These observations suggested that song perception involved sensory and motor pathways. We now show that the act of singing, but not hearing song, induces a rapid and striking increase...

Song learning in songbirds has been studied extensively in males but not in females. Females prefer songs previously heard, but it is not known whether opportunity for learning during the juvenile period affects the ability of females to judge song quality. We show that early exposure to adult song is required in the development of normal adult female zebra finch, Taeniopygia guttata, song pref...

Birdsong is a sexually selected signal that is learned early in life. Song learning (imitative vocal learning) by male songbirds has been extensively studied, but other aspects of development are important in birdsong as well. Female experience with song can affect song preferences in some species but not in others. The neural responses to song in females, as assessed by immediate-early gene ex...

A Z-R relation is derived using a data set which consists of nine rain events selected from Singapore’s drop size distribution. Rain events are separated into convective and stratiform types of rain using two methods: the Gamache-Houze method, a simple threshold technique, and the Atlas-Ulbrich method. In the Atlas-Ulbrich method, the variability of the rain integral parameters R, Z, Nw, D0 and...

Variability in adult motor output is important for enabling animals to respond to changing external conditions. Songbirds are useful for studying variability because they alter the amount of variation in their song depending on social context. When an adult zebra finch male sings to a female ("directed"), his song is highly stereotyped, but when he sings alone ("undirected"), his song varies ac...

Song repertoires may be a product of sexual selection and several studies have reported correlations of repertoire size and reproductive success in male songbirds. This hypothesis and the reported correlations, however, are not sufficient to explain the observation that most species have small song repertoire sizes (usually fewer than 10, often fewer than five song types). We examined a second ...

Most songbirds learn their songs from adult tutors, who can be their father or other male conspecifics. However, the variables that control song learning in a natural social context are largely unknown. We investigated whether the time of hatching of male domesticated canaries has an impact on their song development and on the neuroendocrine parameters of the song control system. Average age di...

Adult male zebra finches (Taeniopygia guttata), as closed-ended learners, normally crystallize their songs at 90 days of age, and the song remains fixed throughout life (Price, 1979). We show that injuring the tracheosyringeal nerve(s) (each of which innervates the ipsilateral half of the syrinx, the avian vocal organ) results in a short-term deficit in the syllables forming adult male song; th...