music found in non-human animals is birdsong. Birdsong is different from normal calls. For example, a call will usually simply function to communicate a direct message. For instance, a bird call could be used to direct attention that a predator is near. Meanwhile, a song contains more repetition and usually will have distinct structure to it, with a specific beginning, middle, and end. In many species of songbirds, songs seem to be used both as a way to attract potential mates, as well as to mark and defend one's territory. It has been observed that young songbirds acquire their ability to produce song from imitation of adult birds. There seems to be a critical period for song learning. In one experiment, they compared birds raised in isolation, (this involved isolation from other birds as well as the vocalizations of other birds), with those raised in a colony, without these forms of isolation. Using an fMRI scan and the blood oxygen level dependent (BOLD) as a measurement of brain activity, it was found that birds raised in the isolation condition did not appear to show a preference between their own songs and a repetitive song. Meanwhile, colony-raised birds showed a stronger reaction to their own song being played back. Mimicry Several species of birds can mimic the songs of other birds, or even mechanical sounds. These include, with varying degrees of success, starlings, mockingbirds, thrashers, crows and ravens, parrots, myna birds, Blue jays, Lyrebirds, Lawrence's thrushes, Acrocephalus (bird) (March warblers), and others. Mozart kept a starling that could mimic some of his music. Functions and effects of music on animals Mammals Snowden and Teie performed an experiment on Cotton-top tamarins, Saguinus oedipus, to determine if music would lead to behavioural changes, and whether music made by other species would elicit similar behavioural responses as the music of one's own species. This experiment involved two separate categories of music - one was affiliation-based, the other was fear/threat-based music. Within the two categories, the experimenter varied whether the music was produced by humans or tamarins. During the experiment, a baseline behaviour measurement was established, proceeded by the experimental condition, which was a piece of music that was played for 30 seconds. Following this, behaviour was analyzed for a total of 5 minutes. This analysis was made by an observer who was unaware of the true hypothesis of the experiment, and simply noted different