<p>We conducted researches on the call of a young Japanese Green Pigoen (less than 1 year old at the start of the survey) in captivity at the Gyotoku Bird Observation Center in Ishikawa City, Chiba Prefecture. Using an IC recorder with Ðimer recording function we were able to analyze the number of and changes in the calls of Japanese Green Pigeons (born in the previous year) during their first breeding season.</p><p>1)The maximum frequency of each phrase of the Japanese Green Pigeons 1 year after birth is low when they first began to call. And the frequency becomes into standard voice pitch thereafter but it is considered to be unstable and incomplete. Also, there seemed to be no apparent difference in the length of the calls compared to the voice pitch. It is thought that this is because they don't yet have the ability to control the voice pitch when they first begin to call. They appear to be able to slightly adjust the length of the phrase early on. And they gradually develop the ability to control the pitch and finally details of each phrase (shape of voiceprint) are arranged into a standard call.</p><p>2)All Japanese Green Pigeons seem to develop the standard call in about 1 year after birth though it is still unstable.</p><p>3)Calls in the wild at the first peak of the number of calls are made during the time when Gyotoku Female 17 has not begun “oao” call including up to 10th phrase. This is thought to be because the wild population consists of adult birds.</p><p>4)The time when “oao” calls of Gyotoku Female 17 increase was after the trough on June 28. This coincides well with the assumption by Komatan (2018) “Calls of the population born in the previous year become the standard call as it calls frequently after June 28” .</p><p>5)Pigeons are not songbirds and they do not sing but only have certain calls. By its completion it may be said that a condition to get a mate is met but considering that “popopo” call was not made in their second year it is assumed that individuals in the second year after the birth do not breed that year. In the transition period till the standard call is made during survey period, the call with all 10 phrases (standard call) was made from 7/20 to 8/21. Even thought it is considered the standard call, 1st phase and the length of the call was still unstable.</p><p>6)The fact that the call of reared and non-breeding Gyotoku Female 17 (born in the previous year) showed the similar seasonal cycle of calls as wild Japanese Green Pigeons suggests that the secretion status of the hormone level with regard to the call was in the same seasonal cycle. This may be because their ability to control the voice pitch has not yet been developed when they start to call. It seems that they can make the delicate adjustment of the length of phrases at an early stage and then the ability to control the voice pitch is gradually developed, and finally the details of each phrase (shape of voiceprint) is arranged into the standard call.</p>