Analysis of individual differences in the call structure of Japanese Green Pigeons

Abstract

From April 18 to October 10, 2015 analysis of recorded calls of wild Japanese Green Pigeons at Komayama, Oiso, Kanazawa Prefecture was carried out. Also the differences in recorded calls of individual rescued Japanese Green Pigeon were analyzed.

1) Confirmation of 2 call types was made: “oao”, “popopo”. The “oao” call was heard from May 2 (first heard day) to October 10 (last day of survery) and the “popopo” call was heard from May 2 to August 7 at the Japanese Green Pigeon survey site.

2) The basic song (“oao”) can be broken down into syllable1~10 .

3) The frequency range (lowest to highest) of wild Japanese Green Pigeons sounds was from 617Hz to 1242Hz. The average was 714Hz~1066Hz.

4) Songs in the lowest frequency mainly consisted of syllable2 (96.7%)

5) Songs in the highest frequency consisted of 2 main syllable6: 61.1% and syllable8: 22.2%. These 2 sounds accounted for a total of 83.3% of the sounds in this frequency.

6) Comparison of lowest frequency songs rising and highest frequency songs rising showed an average of 713Hz in the lowest frequency compared to 1072Hz in the highest frequency (difference of 359Hz).

7) The length of each sound type in all calls (syllable 1~10) ranges from 0.38~3.42 seconds. The average was 0.88~2.38 seconds.

8) The length of the shortest calls were: syllable 5 (32.2%), syllable 9 (35.6%) , syllable 10 (22.2%). This was a total of 90.0% and range of 0.38~1.07 seconds.

9) The longest length of each song sound was 36.7% in syllable 1 and 45.6% in syllable7. The total of the two syllables was 82.3%. The range length was 1.76~3.42 seconds.

10)The range of all song lengths was 18.25~25.39 seconds. The average was 22.33 ± 1.42 seconds (SD)

11) The highest frequency of all rescued Japanese Green Pigeons were all (with the exception of syllable 10 of 12 Rescued Japanese Green Pigeon at Gyotoku) in the same frequency as wild pigeons.

12) The length of time of each sound type in rescued Japanese Green Pigeons were in the same range as wild pigeons.

13) The individual voice print shapes of each rescued Japanese Green Pigeons calls were different.

14) Each of the wild Japanese Green Pigeons high frequency lengths standard deviation compared to the rescued birds standard deviation was more than 1.9~3.9 times with a wide variation.

15)The song length of all the wild Japanese Green Pigeons standard deviation compared to rescued pigeons standard deviation was 3.5 times with a wide deviation.

16) The highest frequency, song length and voice print shape of 3 rescued Japanese Green Pigeon did not change over the years.

17) The difference in the minimum and maximum values (range of dispersion) of the highest frequency and song length of syllable 2 was used to make a scatter diagram.

18) There is some difference in each individual birds call but even less of a difference over the years in all of the birds calls which makes it possible to use this to identify individual birds.