Birdsong Overlapping: Random Coincidence or Acoustic Interactions.

Birdsong overlapping may either indicate communicative interaction between birds or be a simple coincidence. We developed a program that allowed us to mathematically modulate the independent singing of birds with a given level of song rate. This permitted us to statistically evaluate whether song overlapping is a random coincidence or real acoustic interactions between birds.

Seasonal Dynamics of Testosterone and Corticosterone in Predatory Birds as Exemplified by the Northern Goshawk (Accipiter gentilis).

Testosterone and corticosterone are steroid hormones that regulate various aspects of bird behavior. The dynamics of blood level of these hormones depending on the stage of the life cycle have been studied in many species. It has been shown for both sexes that the levels of both hormones rise during the breeding season.

Genes and song: genetic and social connections in fragmented habitat in a woodland bird with limited dispersal.

Understanding the processes leading to population declines in fragmented landscapes is essential for successful conservation management. However, isolating the influence of disparate processes, and dispersal in particular, is challenging. The Grey Shrike-thrush, Colluricincla harmonica, is a sedentary woodland-dependent songbird, with learned vocalizations whose incidence in suitable habitat patches falls disproportionally with decline in tree cover in the landscape.

[Formation of passerine (Passeriformes) vocalization in ontogeny: the current state of the problem].

It the acoustic signal system of birds, songs and calls are distinguished. Up to the late 1970s, the attention of researchers was focused primarily on studying the process of song formation; the patterns of the call system formation remained virtually unstudied. In this field, the prevailing notion was that, since all calls are hereditary, their formation in the repertoire of all birds is similar.