The adult Yellow-vented Bulbuls (Pycnonotus goiavier) were always careful when flying into the nest to feed the chick HERE and HERE. They do not fly in directly but land some distance away.
One favourite spot when arriving after foraging was the Golden Penda tree (Xanthostemon chrysanthus) growing along the road fronting the house, some10 metres away from the nest. Alone or with its mate, the adult would sometimes call loudly – was it contact or warning call? Once it was safe to fly to the nest, it would first fly to a nearer branch (top).
There it would look around and called out loudly should there be danger around – someone in the garden or one or more ‘threatening’ birds were nearby. Danger calls were accompanied with raised crest.
Only when it was safe to do so would it fly into the nest and feed the chick. Sometimes it flew silently in, other times it gave out calls, maybe to signal to the chick in the nest.
YC Wee
Singapore
August 2015
5 Responses
I have observed them over the years. There will always be one perched on high ground to have a commanding view of the whole area around the nest. They do make calls to communicate whether its safe to proceed.
It is interesting to note that although they make calls, the chicks do not respond to them until the parent is in the nest. The chicks make pretty loud calls and will attract predators if they responded to the initial calls by the parents.
Older chicks even learn to keep quiet when the parents make distress calls.
Someone should document these different calls and decipher them…
There is already a good collection listed in chronological order as follows:
1. https://besgroup.org/2011/06/12/baby-birds-calls-yellow-vented-bulbul/
2. https://besgroup.org/2011/11/27/yellow-vented-bulbuls-classical-territorial-call/
3. https://besgroup.org/2013/01/16/calls-of-common-tailorbird-and-yellow-vented-bulbul/
4. https://besgroup.org/2015/02/28/happy-yellow-vented-bulbuls/
5. https://besgroup.org/2015/06/05/dawn-chorus-in-an-urban-garden/
1 and 3 are of the same call from juveniles.
More from my archive to follow soon.
Thanks Chong Hong.
As promised, below are two sound clips, presented as video with visualisation of the sound waveform. The first one is the “morning has broken” song heard during the break of dawn. It is also heard at other times of the time. This particular recording was made around 9am on 2 Apr 2011. The second recording was also made around the same time and date.
https://www.youtube.com/watch?v=jm_lqXUFLn0
https://www.youtube.com/watch?v=jp7m61tSx_E