Two sonagrams (10 sec each) of natural soundscapes, recorded at (top) Pic Paradis, St. Maarten, Virgin Islands and (bottom) at Kalimantan, Borneo. Darker consistent bands are the sounds of insects, with the spectrum of bird calls fitting into the "niches" available in the spectrum. From B.L. Krause, "The niche hypothesis," The Soundscape Newsletter, 6, pp. 3-6, 1993.

Two early sonagrams  (log scale) of Krause's recordings, The Great Animal Orchestra, Little, Brown, 2012.

Examples from David Monacchi's Amazon Recordings
Prima Amazonia: Portraits of Acoustic Biodiversity
Wild Sanctuary WCI-056 2007

Night Soundscape

Dawn Soundscape

Dusk Soundscape

Flooded Forest