ISSS608 2017-18 T3 Assign Sun Shuangtian Kasios’ Recording Investigation
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Contents
Geospatial distribution of the recordings
In our previous analysis, we could visualize the Rose-crested Blue Pipits in the Preserve appears mostly in northeast of the Preserve. Whereas according to the recordings provided by Kasios, Blue Pipits appears around the whole Preserve. This make us doubt the authenticity of the Blue Pipit recordings. Further analysis needs to be done to identify if the recording provided by Kasios are really the call of Blue Pipit.
Spectrogram of True Blue Pipit
In the collection of bird calls from the Preserve which has accurate identifications, we randomly choose 4 Rose-crested Blue Pipit Song recordings and 4 Rose-crested Blue Pipit Call recordings. Then we use R package seewave to break the recording and detect the frequencies respectively.
Song frequency
Call frequency
Pattern Summary
From the spectrogram above We could conclude that he frequency of Blue Pipit songs and calls are both around 5KHz.
Spectrogram of Recordings from Kasios
Acceptable Recordings with Frequency around 5KHz (5 out of 15)
Fake Recordings with Frequency far from 5KHz (10 out of 15)
Frequency Comparison
Compare the frequency of the 15 recordings and the frequency of Blue Pipit song/call, we notice that for most of the 15 recordings, the frequency range are not around 5KHz. This further prove that the recordings that Kasios provided are not Rose-crested Blue Pipit.