log#1_ Pre-research: How noise affect animals' communication?

How exactly noise will affect the communication/behaviour of animals? This is the first question occurred to me. And the pre-research result inspired me to design a granular to modulate the sound of the turtle doves.

According a book, "The Secret Language of Animals", signals or displays carry two basic kinds of information: nonbehavioral (who and where) and behavioral (what and how). [1] Nonbehavioral messages identify the animal by species, gender, rank, and sometimes even individual identity. Communication signals have evolved to fit each animal’s lifestyle and to carry effectively in its habitat. Animals live in an urban environment are easier to change their communication channels.

I also noticed an animal sound study from soundscape ecologist Bernard Krause. In his book "The Great Animal Orchestra", he made a spectrogram to show how human-generated noise affects entire biophonies. [2] Figure 1 demonstrates spadefoot-toad chorusing without any breaks in the sequence and no disruption from human-generated noise. "It is a powerful story told through the aggregate voice of dozens of chorusing frogs in about ten seconds―the length of the audio clip from which this spectrogram was made. In Figure 2, a military jet’s booming noise―measured at approximately 110 dBA―masking the toad vocalizations. Note the breaks in the chorusing and how the toad group energy diminishes." (Bernie Krause, 2013) A soundscape conveys a complex sonic narrative loaded with significant messages.

Figure 1. Synchronous Great Basin

spadefoot toads (Spea intermontana) chorusing.

Figure 2. Spadefoot toad chorusing affected by military-jet overflight.

My ideas for the sound modulation in max/msp were also influenced by the animal's vocalization adjustments. For example, using the pitch, speed, density modulation to change the bird's sound in the granular design.

Animals can behaviorally react to anthropogenic noise in various ways, such as by moving away from the source of the noise (either temporarily or permanently), temporally adjusting their own activities to avoid the noisiest times of the day, or increasing their anti-predator behavior. In addition, many animals change their vocal behavior in an attempt to overcome the cue-masking effects of the noisy environment (both natural and anthropogenic).

The most noticeable vocal adjustments made by animals are:

(i) changing the amplitude of the call (the Lombard effect;

(ii) shifting the frequency of the call;

(iii) changing the temporal structure of the call (timing of modulations, notes, and syllables within the calls);

(iv) altering the timing of the call delivery (e.g., changes to the repetition rates of the call).

“Urban ecology and avian acoustics: Function and evolution of birdsong in a changing world”, birds typically sing to deter competitors and to attract mates. Acoustically they have to cope with natural obstacles such as vegetation and rocks or buildings. Natural soundscapes are increasingly affected by noise from traffic in the air and on the ground and all sorts of industrial and recreational activities. [3]

Cities are often not less species rich than the surrounding natural habitat types, but the composition is very similar in many cities over vast geographical ranges. Urban birds are also reported to be more aggressive relative to nearby birds in the country side. [4]

[1] Benyus, J. M., Barberis, J. C., & Horowitz, A. (2014). The Secret Language of Animals: A Guide to Remarkable Behavior. Black Dog & Leventhal.

[2] Krause, B. (2013). The Great Animal Orchestra (Reprint). Back Bay Books.

[3] Urban ecology and avian acoustics: Function and evolution of birdsong in a changing world. (n.d.). Leiden University.

[4] Berger-Tal, O., Wong, B. B. M., Candolin, U., & Barber, J. (2019). What evidence exists on the effects of anthropogenic noise on acoustic communication in animals? A systematic map protocol. Environmental Evidence, 8(S1).