Make an audio recording of a song bird e.g., bulbul, magpie robin, sunbird. Observe and note the activity of the bird while recording the call. Communication in birds, history of bird song recording, types of bird calls, non-vocal songs, spectrogram,

1. MAKE AN AUDIO RECORDING OF A SONG BIRD E.G., BULBUL,
MAGPIE ROBIN, SUNBIRD. OBSERVE AND NOTE THE ACTIVITY OF
THE BIRD WHILE RECORDING THE CALL

3. Birds communicate information about danger, food, sex,
group movements and for many other reasons via vocal signals. Bird
vocalization includes both bird calls and bird songs. In ornithology a
song is generally defined as a vocalization used in primarily territorial
and mate attraction / retention context. Calls include all other categories
of avian vocalizations. The most complex and beautiful avian
vocalization are songs; this category can include harsh and simple sounds.
Calls can often be attractive to our ears as well, but typically they are
complex / simple and often harsher than songs from the same species.
While in many other species it is easy to distinguish songs and calls, in
many others it is impossible for humans to do so particularly in sound
recordings when the bird cannot be directly observed. Bird songs are
best developed in the order Passeriformes

5. History: The first bird song was recorded by Ludwig Koch in 1889. At the time Ludwig
was 8 years old. He recorded the Indian Shama, a member of the thrush family. Many
years later after Dr. Koch moved to Britain from Germany he worked with E. M.
Nicholas, who became the director of the Nature Conservancy, creating the book “Songs
of Wild Birds”. Evolution and physiology of Bird songs: scientists hypothesize that bird
songs have evolved through sexual selection and experiments suggest that the quality of
bird song may be a good indicator of fitness. The avian vocal organ is called the syrinx. It
is a bony structure at the bottom of the trachea. The syrinx and sometimes a surrounding
air sac resonate to create sound waves that are made by a membrane past which the bird
forces air. The bird controls the pitch by changing the tension on the membranes and
controls both pitch and volume by changing the force with which it exhales. It can
control the two sides of the trachea independently, which is how some species can
produce two notes at once. Birds make a variety of calls, songs and non-verbal sounds
with a language as complex as spoken words.

7. Types of calls:
Alarm calls: These sharp, piercing calls are used to warn
other birds of danger and birds will use them when they
feel threatened. Alarm calls are typically short but loud
and can carry over great distances. Alarm calls may also be
used by aggressive birds to threaten others.

8. Begging calls: Made by young birds, these plea calls
are designed to draw attention and may include small
peeps. Begging calls are not usually loud, but can be
heard clearly in the vicinity of a nest. Birds will
continue to use these calls even after leaving the nest.
Begging bird sounds are frequently accompanied by
using flutters and other motions.

10. Contact calls: When birds travel in flocks or
when they want to signal one another, they use
contact calls. These are moderately loud chirps
and other simple bird sounds that are clear but
not as piercing as alarm calls. Mates may use
them to keep in touch with one another or as a
territorial call for a rival mate.
Flight calls: Many birds have specific calls they
give only in flight and these can be some of the
most useful bird sounds to learn for identifying
birds. A flight call may be slightly more
musical.

12. Songs: Songs are the most distinctive and
familiar bird sounds. These are longer, more
elaborate and generally more musical strings of
syllables that have many purposes. Birds may
use songs to attract mates, to advertise their
territory or to discourage intruders. The
quality, duration and variation of bird songs
depend on the species and there are also
geographical song variations in bird
population.

14. Non-vocal sounds: Many birds incorporate verbal
sounds into their language, some of which can
function similarly to calls or songs. Drumming, wing
beats; wing clapping and bill shapes are all a part of
bird’s verbal communication. Similarly a bird’s feeding
or mating behaviour may provide additional sounds
such as “boom” or “screeching” noises while foraging
that can be useful in proper identification. Songs and
calls play a very important role in the hives of birds.
With all the ways birds communicate, sound is the
most important, because birds do not have high ability
of smell, they rely on vision and sound.

16. How to use bird sounds: birds that are familiar with the different sounds make use of
them for auditory identification. For example hearing an alarm call may prompt an
observant bird to search for birds of prey nearby. When the bird is spotted, the noise it
makes, including the pitch, tone, rhythm and quality of its sounds can help create positive
identification of the species. The song type of calls or courtship calls, territorial and
advertisement calls are generally elaborate and most complex ones. They are long,
continuous with multiple harmonics at double frequency of the fundamental frequency.
This also makes them highly melodious. One of the other alarm calls, begging calls,
mobbing calls is generally related with emergency to pay attention and a quick response
followed by it. Such calls are generally short, sharp and high pitched. Their sonogram is
represented by sharp simple lines, high frequency shrieks or trills which are repeated
several times. This is in accordance with urgency of the situation and communicating
danger to the others.

22. A spectrogram is a visual way of representing the signal strength, or “loudness”, of a
signal over time at various frequencies present in a particular waveform. Not only can
one see whether there is more or less energy at, for example, 2 Hz vs 10 Hz, but one
can also see how energy levels vary over time.

23. There are six ways in which bird sound waves can be analyzed. They are:
duration
pitch
loudness
tone
sonic texture
spatial location

24. THE SEVEN BASIC TONE QUALITIES

25. Conclusion: The calls of red vented bulbul and
black drongo were downloaded from a bird
sound application and the sonograms of these
calls were prepared from free software from
Cornell laboratory – Raven lite 1.2. Alarm call,
territorial call and songs of both the bird species
were taken to make different sonograms. The
recordings of the calls and songs downloaded
contained a lot of background noise.

26. After comparing the call of red-vented bulbul and black drongo, it was observed that
the bulbul call was more continuous and to some extent a monotonous series was seen
with good harmonics. While the drongo call was less monotonous and shows uneven
trills. The Drongo alarm call showed various inflections such as up slur at the start,
down slur in between and over slur at the end with noise can be seen and it was
continuous. In the bulbul alarm call, a sharp under slur in the mid call and very less
harmonics were seen. Comparing the song of Black Drongo and Red-Vented Bulbul, it
was observed that in Drongo extremely sharply up slurred whistle with few harmonics
makes the song nonmusical. In Bulbul, in the beginning a small series of over slurs is
observed with some low pitch sound in the mid call and again a small series of up-slurs
and down-slurs are seen with many harmonics, which makes the sound sweeter. More
scientific and sophisticated recording using professional techniques and equipment’s
would have resulted in clearer sonograms which in turn will yield more valuable
information.

27. Please refer to study in detail:
https://www.allaboutbirds.org/news/how-to-learn-bird-songs-and-calls/
https://www.audubon.org/news/start-using-spectrograms-read-bird-songs-and-calls
https://becausebirds.com/visualize-bird-songs-with-spectrograms/
http://soundbirding.org/index.php/sound-and-spectrograms/
http://earbirding.com/blog/archives/category/spectrograms

28. Thank
Thank
Thank
you!
you!
you!