Digital Study On Calls Character Of Crested Ibis In Breeding Season

The crested ibis is an endangered-class bird in the world now,belongs to the first-class protected bird in our country.By twenty years efforting the number of crested ibis is apparent increasing,since it is found at Yang-county in 1981.But the crested ibis doesn't absolutedly escape endangered threat.Bird songs and calls contain abundant information.They have important signification whether in specis classify, transformation,evolution or in biology,behavior.Simultaneity they will be applied diffusely also.At present.overseas and our country scholar mostly describe simply not study wholly on calls of crested ibis.The study can more know crested ibis's physiological and behavior machine-made.Moreover it is important in knowing it's biology meaning,species structure and classification.It improve hopefully immunity energy and artifical breed of crested ibis.It also provides fundamental data for systemic study of crested ibis call.Songs and calls of artificial feeding crested ibis are recorded from Shaanxi Rare Wild Animals Rescuing and Breeding research Center in breeding seasons.The songs and calls are analysed in time domain,frequency domain,time-frequency domain.From analysing in time domain we can know duration time and interval time of call .The analysis of frequency domain shows frequency range,main energy range,principle frequency,sub-peak frequency and fundamental frequency.The analysis of time-frequency domain indicates frequency of particular time.At same time,the singularity singal is detected and the noise of call is removed by wavelet analysis.In the paper five kinds of crested ibis call are analysed and studied,i.e. mating call,preen call,alert call,squab call ,poult call.The result shows that the mating call is classified as mating call and mimic mating call.The mating call is pressing and shivery with duration time 9.3±2.5s(n=125),frequency range(FR) 250⁵000Hz,main energy range(MER) 350³500Hz,principal frequency(PF)1055Hz,sub-peak frequency(SB) 1453Hz,2250Hz,3093Hz,fundamental frequency(f₀)375Hz.Its spectrogram turns out to be multi-harmonic spectrum and one structure.Mimic mating call has three kinds with duration time 8.2±6.4s(n=169).The first kind call is only long call with duration time 1.04s,FR 0¹0000Hz,MER 200⁵000Hz,PF 1312Hz,SB 984Hz,3000Hz,3468Hz, 4500Hz,5015Hz,5535Hz,f₀ 328Hz.Its spectrogram has three frequency bands(FB). Thesecond kind of call is some pressing songs with FR 0¹0000Hz,MER 200³000Hz,PF 1078Hz, fo 328Hz. Its spectrogram has two frequency bands.The third kind call is pressing call and long song with FR 0¹0000Hz,MER 200³000Hz,PF 984Hz,SB 1359Hz, fo 375Hz. Crested ibises often preen after resting,taking food ,bathing,rubbing back. The preen call is with FR 0⁶000Hz,MER 200¹830Hz,PF 891Hz. Its spectrogram has no obviouse frequency bands. The alert call is with FR 200⁵000Hz,MER 250¹500Hz,PF 937Hz,SB 2015Hz,3046Hz,3750Hz, fo 375Hz. The squab call is classified as hatching out before,batching out today,hatching out five days.The call before hatching out is short with FR 1875¹0000Hz,MER 2000⁷000Hz,PF 3187Hz,SB 2390Hz,3937Hz, 4687Hz, 6187Hz,7406Hz, f0 890Hz. Its spectrogram has only spectrum outline.The call of hatching out today is longer with FR 375Hz¹0000Hz,MER 1600⁵000Hz,PF 3140Hz,SB 2671Hz,4406Hz, f0 890Hz. Its spectrogram has no obviouse frequency bands.The call of hatching out five days is also longer with FR 700¹0000Hz,MER 1400-3100Hz,PF 2578Hz,SB 2109Hz. Its spectrogram has two frequency bands and harf-arched structure.The young crested ibis hardly calls.Its call is with FR 400⁵000Hz,MER 500²000Hz,PF 1359Hz,SB 225OHz,2859Hz,fo 984Hz. Its spectrogram has no obviours frequency bands.