Bird Calls and Song By Andrew Mascarenhas Contents  Some history  Songs and calls  Is understanding bird sound useful?  Recording what we hear  ‘Seeing’ what we record  Goa on the bird audio map As every birder knows, as soon as one steps in to a forest, you very often HEAR a bird long before you SEE it. This is especially true in evergreen forests with dense foliage where it may take several minutes of focused search to finally spot the bird with your unaided eye or with binoculars. While ‘sight’ can only be linear, ‘sound’ travels around objects and just floats through to your ears! The ability to sing is not given to all birds. It is most developed in the order Passeriformes [perching birds] which constitutes roughly half of the world’s ~9,000 known bird species. Birds also produce sound by other means eg drumming of a woodpecker, whirring of feathers of a Kalij Pheasant and bill clatter of storks. The questions worth asking are: should we consider calls and songs to be just ‘noise’ that birds just happen to make and, if not, what do these avian vocalizations [fancy words for calls and songs] mean and what can we learn by studying them? Some history Even early ornithologists in India felt it important to include a description of the calls/songs of specific birds as a method of identification. As examples, Hugh Whistler in his landmark ‘Popular Handbook of Indian Birds, 19491 had the following to say about Lapwings and the Greenshank: Red-Wattled Lapwing: “The call is a series of loud shrill notes well expressed by the words, didhe-do-it pity-to-do-it usually uttered on the wing when the bird is disturbed.” Yellow-wattled Lapwing: “The call is a plaintive dee-wit dee-wit, much less harsh and loud than that of the last species {Red-wattled} and the bird is altogether less demonstrative.” Greenshank: “It is rather a shy bird, and when disturbed flies off with swift and erratic flight rising high into the air, and as it goes it utters a loud alarm whistle, a mellow but plaintive thewthew tewtew-theeuw. The ordinary call in flight is chee-wit.” In India, the desire to record birds is not new. In 1999, the following news item appeared in the Indian Express newspaper: MUMBAI, MAY 9: “BNHS releases `bird tapes': As a part of the bird conservation programme, the first ever bird call tapes produced by Bombay Natural History Society (BNHS) was released on Saturday. The bird call project began in the 60s,

while Oxford ornithologist B C Bertram was studying the racial differences between three varieties of `Hill Mainah', which is possibly the finest mimic among birds, according to BNHS public relation officer Isaac Kehimkar. During the studies Bertarm recorded calls of several Himlayan birds in his spare time and later he donated 12 tapes of Himalayan bird calls to the society. In addition, 30 tapes recorded by Brother Antonio Navarro2 were received from the Bombay St. Xaviers Society. Br. Navarro's recordings were mainly of the birds of the Western Ghats.” Some 200 years before Bertram, another British naturalist Gilbert White [1720-1793], was already grouping birds by differences based on the seasonal timing of the birdsong that he observed in the village of Selborne: “According to my proposal, I shall now proceed to such birds [singing birds, strictly so called] as continue in full song till after midsummer, and shall range them somewhat in the order in which they first begin to open as the spring advances”3 Like other animals and humans, birds sing or call to communicate with each other in a variety of ways. The understanding of this communication has progressed rapidly especially in the past 50 years partly driven by the ease of recording [due to the dramatic reduction in size/weight of audio recorders by miniaturization] as well as new software to analyze sound. Why do birds call or sing? a. Is there a difference between calls and songs? The following generalizations can be made: Call Nature Un-musical Length Brief Amplitude Can be soft Repetition Solitary Complexity Simple Season All year Gender of Male & Female bird Energy Minimal energy expended by bird

b. Why do birds vocalize? Again, calls and songs may have different uses: Call Reason Signal danger/alarm; communicate with family & during migration. Species

Alarm calls can often be understood by other species

Song ‘Musical’ to the human ear Long Loud Highly repetitive Complex Breeding season Usually male Huge energy needs due to high volume of songs/day during breeding period

Song Announcing presence to Mark & defend territory Indicate fitness & health Find a mate Species-specific

c. How do birds learn to sing? This is still a hot research field and knowledge is constantly being expanded. However, it is generally thought that birds acquire their singing abilities through a combination of DNA-inheritance and exposure to their surroundings ie a bird is born with a speciesspecific song template. Then, as juveniles, this template is filled out and fine-tuned as they listen to and absorb the songs of their parents and their neighbours. d. Other interesting aspects of avian vocalization: i. Location when singing: birds often tend to perch at a high elevation [top of trees] to project sound. When the natural habitat is empty of trees, birds sing in flight. Dense vegetation versus light vegetation influences the type of sound that will carry and that birds will use. Sound is the only way that nocturnal birds can communicate. ii. Dawn chorus: all birders know that getting in to the forest early to catch the dawn chorus is important. But why do we witness such a ‘burst of sound’ before sunrise. Several reasons are suggested: birds have woken up and are marking out their territories to their competing neighbours even when it is still dark. ‘I am here and fit as a fiddle, where are you?” When the early rays of sunshine finally penetrate foliage, the proverbial ‘early bird gets his worm’ but only after his kingdom has been made secure. iii. Song complexity: Similar to human males serenading young ladies [as in Goa of old!], research suggests that birds compete with one another for the attention of their mate via song and that females pair sooner with the better singers. iv. Mimics: certain species weave into their own songs, the vocalization of other birds, animals and even man-made sounds. Drongos and Shrikes are excellent mimics. Reasons for mimicry are still being investigated but include sexual selection [indicating fitness], protection against predators etc. v. Alarm calls: because predators [winged or otherwise] can attack silently and without warning, birds have developed a highly effective alarm system. The ‘alarm call’ sometimes has universal applicability ie the alarm is not only for its immediate family but is acted upon by neighbouring birds of other species as well. These calls can be specific and are often related to the type of threat eg cat on the ground versus a hawk in the air. Is understanding bird sound useful? We spend considerable time identifying birds and we mainly do this by ‘sight’. This explains the vast number of photographs taken by birders. But what if could add ‘sound’ as well to the package of knowledge of a particular bird. First, even before we see the bird, we can do a rapid ID and then, by listening carefully, we can start to do some analysis: juvenile vs adult, song vs call, reason for vocalization etc. Sight and Sound makes you a better all-round birder. Recording what we hear I can hear you saying: “Well, what do I need to get started?” You are more fortunate than Br. Navarro was back in the late 1950s. He used a bulky ‘Uher’ reel-to-reel tape recorder which was the size of a small roll-on suitcase and was carried on the back of a coolie with a separate electricity source. Today’s recorders are tiny in

comparison [see below]. They vary in size and weight: from a laptop to a smartphone. Most have their own built-in batteries which give you power for several hours of recording. In addition, they record digitally which makes for use of modern analytical audio software.

OR Tascam Recorder PD2-HP* Digital Recorder

Reel-to-reel Tape Recorder Back then….!!

Tascam DR-05* Combo Digital Microphone & Recorder

Today…

* There are several excellent models available on the market today at reasonable prices

Recording birds is not dissimilar to recording a singer. You would need the same basic components: a microphone to pick up the sound waves with an audio recorder to [digitally] record/playback that sound + headphones to monitor the sound as you record and reduce outside noise.

+ Singer

Microphone -Recorder

Headphone

In recording birds that are obviously quite some distance away, you need ONE additional tool that helps to bridge that distance. It is an add-on which helps concentrate and focus the incoming sound in to your microphone. This is called a Parabolic reflector…see below:

+ Bird

Parabolic Sound Reflector

+ Combo MicrophoneRecorder

Headphone

The parabolic reflector is very similar in concept and function to the TV dish that points to a transmitting satellite and brings the signal in to your TV.

Lest you think that such equipment is outrageously expensive, some of the birders in Goa have assembled a professional audio recording system [see below] for a sum total of Rs 6,900. Compare this with the average cost of a good camera + telephoto lens of Rs 58,000.

+ Bird

Est. Cost

+

Plastic Gamla

Tascam DR-05

Parabola & components

Combined MicrophoneRecorder Rs 6000/-

Rs 200/-

= Sony Zx100

Headphone

Rs 700/-

Rs 6900/-

‘Seeing’ what we record With the advent of digital recorders [replacing the older analog tape recorders], modern audio analytical software lets us convert these audio inputs into visual images. Comparisons of these audio-visual ‘fingerprints’ of a bird’s vocalization can tell us a lot about its owner and their behavior. Commonly use audio software includes Raven Lite [free], Audacity [free/open source] and Adobe Audition [expensive].

The audio recording below of the Indian Pitta was made by Eveny Luis in Aldona, Goa on 26May-2012:

Photo by Samir V.Naik

Link to Call

Putting Goa on the world Audio Map Despite Goa being the smallest State in India, it is has now more active bird recordists than any other location in India. With close proximity to the Western Ghats, we can add this new dimension to our study of birds and bird behavior and thus help protect our vulnerable bird population in an increasingly fragile environment. Till date we have 694 bird call/song recordings from Goa alone!

Audio Recordings from Goa http://www.xeno-canto.org/explore/region

1. 2. 3.

Whistler, Hugh: Popular Handbook of Indian Birds, Gurney & Jackson, 4th Edition, 1949 A member of the staff at St Xavier’s High School, Dhobi Talao, Mumbai. The well known Dr Erach Bharucha was a major force in transferring these recordings to cassette tapes and subsequently to CDs. White, Gilbert: The Natural History of Selborne, Constable & Company, 1989, p146 [Google Books]