Friday, May 28, 2010

NESTS and YELLOW-VENTED BULBULS

     The Yellow-vented Bulbul (Pycnonotus goiavier) is one of the most common birds in Ayala Alabang. Yellow-vented Bulbuls can be seen perched on branches of trees in most gardens and parks all over the village. They are bold birds and are not easily frightened by people or other birds. They are relatively easy to observe. Sometimes they flock together in one tree in a boisterous group of up to 20 individuals. A close inspection of a noisy tree or shrub will often yield a group of Yellow-vented Bulbuls making a variety of musical “chup-chup-chup” calls.
     
     The Yellow-vented Bulbul is bigger than a Eurasian Tree Sparrow or maya. It is about 7 ½ inches long. When seen from behind, the Yellow-vented Bulbul looks very non-descript and it can be mistaken for many other bird species. The back of its head, tail, and throat are an undistinguished looking olive-brown color that is common to many other birds. In birding terminology, the distinguishing features that help identify a bird are called field marks. The field marks of the Yellow-vented Bulbul are the black stripe on the top of its head, broad white eyebrow, black mask-like rings around its eyes, white breast and belly, and yellow below the belly, right before the tail. This is the yellow vent that gives it its name.

     photo by Tonji Ramos

     Yellow-vented Bulbuls nest at this time of the year. They make cup-shaped nests in dense bushes usually 3-5 feet off the ground. Like many small birds, the male and female bird both share in parenting duties. They take turns sitting on the eggs and later feeding the young. They parents keep the nest clean by carrying out the fecal sac of the nestlings. The fecal sac is the feces of the nestlings that are neatly wrapped in membrane. The parents continue feeding and caring for the baby birds even when they have fledged or left the nest. The fledglings stay in the area of their nest, taking short flights from branch to branch under the watch of the parents.


     
     Unfortunately, despite all the care and attention parents give to their young, some nests fail. When people approach a nest to do gardening or just out of curiosity, the nestlings can get so frightened that they jump out of the nest. Once they do this, it is impossible to return them to the nest. When parent birds feel threatened by people or predators that are approaching their nest, they will stay away from it to keep it from being discovered.


     
     Seeing birds nest in the village is a good sign that Ayala Alabang truly is a bird-friendly village. Sadly though, there are still incidents of bird cruelty in the village. A few weeks ago, a resident of Saranggani St. saw several maintenance men running in a suspicious manner towards a Black Naped Oriole nest. They were carrying a long bamboo pole, presumably to rob the nest. The men were maintenance workers of the Ayala Alabang Country Club. Thankfully, the resident was able to stop the men and report them to the club.
     
     It is likely though that most people in the village do not want to intentionally harm or disturb a nest. The best thing to do when you come across nest is to simply leave it alone. If there is some gardening work that needs to be done in the area where the nest is, it is best to just put it off temporarily until the nest has been abandoned. This will not take too long, not more than 3 weeks for small birds like the Yellow Vented Bulbul. Areas that are known to be popular nesting sites should not be altered to encourage the birds to nest there again. If you want to observe a nest, it is best to do so from a distance or a place where the birds cannot see you so that the bird family will continue with their natural behavior.
     
a fledgling, photo by Tonji Ramos

     Just a little care and consideration will go a long way in making Ayala Alabang a place where all kinds of families, including Yellow-vented Bulbul families, can grow and be nurtured. 

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4 comments:

  1. Sylvia and Tonji -- Your photographs are simple exquisite, the accompanying texts totally engaging and educational. More! More! tmtanseco-cruz

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  2. okay-that was "simply" exquisite!

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  3. Hi, I have a YVB nest just beside my windows in the air well for a month. There is a nestling just like the one shown in your photo.
    I heard the parents' distress call this morning and only found the little bird on ground. It looked very frightened. I put it back to the nest (with hand gloves on). And it kept quiet for a good 30 min. Even the parents didn't know that it was back. They kept looking in the air well. Another 30 min, the parents were very noisy again. I went to check out of concern. And there it was, out of the nest again.
    Is it a flying lesson?
    What should I do? There is a cat family on my rooftop. The kittens "fall" down occasionally when they see something desirable. That's why I'm so worried about the nestling.

    Really appreciated if you could advise me on this.
    Thanks

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    1. Hi Fei, thanks for writing. I'm sorry for this very late reply. If the baby looks like the one in my pictures, then it's a fledgling. That's the stage when it starts leaving the nest. I agree with you that it was probably a flying lesson. Fledglings really are very clumsy. It's a dangerous stage in their life, when they are at risk of being eaten by predators like cats. Especially since cats are such efficient hunters! The only thing I can think of that you could have done is to put a bell on the cats to give the birds a better chance of escaping from the cats.

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