Similar to humans, songbirds rely on auditory feedback to maintain the acoustic and sequence structure of adult learned vocalizations. When songbirds are deafened, the learned features of song, such as syllable structure and sequencing, eventually deteriorate. However, the time-course and initial phases of song deterioration have not been well studied, particularly in the most commonly studied ...

The perception of song is vital to the reproductive success of both male and female songbirds. Several neural structures underlying this perception have been identified by examining expression of immediate early genes (IEGs) following the presentation of conspecific or heterospecific song. In the few avian species investigated, areas outside of the circuit for song production contain neurons th...

In adult male zebra finches, transecting the vocal nerve causes previously stable (i.e., crystallized) song to slowly degrade, presumably because of the resulting distortion in auditory feedback. How and where distorted feedback interacts with song motor networks to induce this process of song decrystallization remains unknown. The song premotor nucleus HVC is a potential site where auditory fe...

Neighbouring song sparrows, Melospiza melodia, in our Seattle population share song types and sometimes respond to neighbour song by type matching (replying with the same song type being sung) or repertoire matching (replying with a shared song other than the type being sung). Based on our modification of the threat hypothesis of Krebs et al. (1981, Animal Behaviour, 29, 918–923), according to ...

Songbirds such as the white-crowned sparrow memorize the song of conspecific adults during a critical period early in life and later in life develop song by utilizing auditory feedback. Neurons in one of the telencephalic nuclei controlling song have recently been shown to respond to acoustic stimuli. I investigated the auditory response properties of units in this nucleus using a technique tha...

In this paper we focus on the potential advantage song repertoires may provide in singing interactions between two birds. We have previously shown that neighbouring song sparrows, Melospiza melodia, in our population countersing with shared songs: a bird escalates an interaction by replying with the same song type his neighbour just sang (‘type matching’), or sends a directed but less threateni...

In this paper, we introduce the concept of generalized -contractivityof a pair of maps w.r.t. another pair. We establish a common fixed point result fortwo pairs of self-mappings, when one of these pairs is generalized -contractionw.r.t. the other and study the well-posedness of their fixed point problem. Inparticular, our fixed point result extends the main result of a recent paper ofQingnian ...

Songbirds (Oscines) learn their songs from a tutor. It is not known where in the brain the memories of these learned sounds are stored. Recent evidence suggests that song perception in songbirds involves neuronal activation in brain regions that have not traditionally been implicated in the control of song production or song learning, notably the caudal part of the neostriatum (NCM) and of the ...

Avian song learning involves memorizing and reproducing song material produced by conspecifics. In several species song repertoire size correlates with the overall volume of two song-related brain regions, the HVc (acronym used as the proper name) and the robust nucleus of the archistriatum (RA). We raised male zebra finches with two adult tutors and found that individual differences in HVc vol...