ANGRY BIRD, STUPID BIRD

posted in: Nesting, Nesting-failed | 6

“A year ago I chronicled my travails, having to play surrogate parent to an orphaned Yellow-vented Bulbul (Pycnonotus goiavier ventris) LINK.

“Over the last four months I have had the misfortune to witness four failed nestings of the resident pair of Yellow-vented Bulbuls that treat my garden as the centre of their territory. These observations have led me to two conclusions.

1) Yellow-vented Bulbuls do re-use old nests.

2) If they weren’t so prolific, they would long have been extinct, because the things they do when nesting are downright stupid.

“Here’s a pictorial record of what happened.

“Just before Chinese New Year this year (February 2013), I was doing some spring cleaning and plant trimming when I saw a Yellow-vented Bulbul nest in a clump of Sword Fern (Polystichum munitum), an introduced exotic fern (below left). The nest was barely 60 cm from the ground. I immediately stopped trimming and said to myself that I would take some photos, but never got around to doing so.

“All went well until the eggs hatched and the babies started begging for food. That attracted the attention of one of my three cats, and the ruined nest (directly over the three thick hoses) is the only picture I have of this breeding attempt.

“A couple of weeks later (March 2013), I saw another nest, built about two meters away from the first one, but just as low to the ground. The photos show the eggs (above right), the female brooding the eggs (below).

“The nest is just to the left of the Birds Nest Fern (Aspleniun nidus), immediately behind the leaf that comes out at a 45 degree angle. You can see that it is barely 60 cm from the ground, only two meters from the wall of my house, and right next to a footpath along which I walk several times per day to feed the fish in the vat sunk into the ground.(below left).

“All was well as long as only the female sat quietly on the nest. But as soon as the babies hatched, there was a flurry of activity. The male and the female came fluttering by to feed them frequently. Needless to say, this activity soon attracted unwanted attention from my cats, and that concluded the second nesting attempt.

“I was watering the plants in the pavilion where I sit to watch my aquariums when I noticed strands of fibres in my Cattleya orchid. I threw them away, but the next day, there were more. I realised that the YVB were again trying to nest, so I let them be. This was in early April 2013.

“That was not the best place to start building a nest.

“The photo (above-right) tells the whole story. The pot of Cattleya with the completed nest in it can be seen hanging from a beam dead centre at the top of this photo. The bench is where I sit to watch my fish. Under the bench is a large feline which is probably the laziest animal in the world. The only thing he hunts for is a better life. But my other cats are definitely much more predatory.

“There were eggs. The mother brooded. The babies hatched. All went well until they grew old enough to start begging for food and making noise. Cats have sharp hearing.

“I left the nest in the Cattleya, thinking that I would repot the plant soon. But I then had to go away for a while. During my absence, as I could not depend on anyone to water my plants regularly, I took all those under cover in the pavilion and moved them outside to where they could get rained on.

“Returning home three weeks later, I started hanging various pots of orchids under cover in the pavilion again. I put the Cattleya in a different position, about two meters to the right from where it was originally. Within a few days (May 2013) I found the female YVB brooding in the old nest, to which the parent birds had made some repairs.

“The above wider-angle shot is to show the context in which the nest was placed.

“Yes, there were eggs, yes they hatched, and the same thing happened again.

“My conclusion is that adult YVB are quite good at remaining unobtrusive. They hunker down very low in their nests and do not move. While brooding, they are hard to notice. And they allow humans to approach very close. I water my orchids daily (except for the pot of Cattleya with the nest in it) and I feed my fish three to four times daily. Plus, I carry out quite extensive aquarium maintenance twice a week, scrubbing the algae off the glass and changing the water. The parent birds don’t move when I am doing all this within one meter of them (below).

“I could have obtained very close-up photos if I had wanted to, as I did in this case. But my objective in this article is not to show portraits of the YVB but to show the context in which their nests are located.

“Though it has been reported that there can be up to five eggs, in all the nestings I have ever observed, both in my house and elsewhere, I have always seen either two eggs or fledglings.

“Once the babies hatch, there is constant coming and going. And when the babies just sprout their feathers, they are very, very noisy and demanding. And sorry to say, the tale often ends at this point.

“By the way, they have started nesting again, this time on the clump of Calathea whose stems can be seen in the very first photo in this article. I will take photos when the weather is less hazy.

“Why do the YVB insist on nesting so low, and insist on staying in this area?

“I can only speculate, but my theoretical answer to the first question is to avoid competitors. There are plenty of koels” and orioles here. Both are aggressive, and compete for the same food as the YVB.

“My thoughts on the second question are that the area in and around my garden is a prime territory for frugivorous birds. My neighbour plants rambutans (Nephalium lappaceum) and chikus, (also known as sapodilla, Manilkara zapota) which she does not always harvest. Directly across the road is a Noni tree (Morinda citrifolia) which fruits regularly and attracts lots of birds.

“In my garden itself is a big Ficus benjamica as well as a row of mature Straits Rhododendron (Melastoma malabathricum). I also have several large Murraya paniculatum and Wrightia religosa plants in pots. The bulbuls eat the fruits of the Ficus, Rhododendron and Murraya, and forage among the Wrightia for insects. I have not yet noticed them taking nectar from the Wrightia as sunbirds often do.

“Following the four failed nesting attempts, the Yellow-vented Bulbuls again tried to build a nest about 80 cm off the ground, and only about 1.5 meters from the site of their first failed attempt.

“Needless to say, the nest-building activity attracted the attention of the cats. Fortunately, in this case, eggs had not yet been laid, but the arrival of a fat feline on top of the nest caused major structural damage. The parent birds made off unharmed, but the same cannot be said of the nest, which is in a sorry state.”

Lee Chiu San
Singapore
25th June 2013

6 Responses

  1. Wow, Your conclusions from what you observed are truly unbelievable. You allow your cats to move around outside, where there are nesting birds and when they predate the nests you accuse the BIRDS of being stupid? I’d have to say you are looking in the mirror at the only stupid individual in this situation. These birds did not evolve with introduced, voracious predators like house cats. The cats on the other hand are natural killers of birds. Recent studies by scientists in the U.S. reveal that pet cats may be the single largest source of bird mortality in the country! The only stupidity is letting these cats wander freely outside to pick off these nests. This is truly an amazingly ignorant post.

    Andy

  2. Lee Chiu San

    If some birds on CITES Appendix I or on the Red List had nested in my garden, I would have packed the cats off to a boarding cattery for the duration of the breeding season.

    But with true Singaporean pragmatism, since YVB are relatively common and not in any danger of extinction, I allowed nature to take its course.

    I happen to like birds. And I also happen to like cats. And yes, my cats have run of the house and garden. In any natural situation, birds learn to adapt. There will always be a degree of attrition, which is natural for any species. There are also squirrels where I live, and a monitor lizard more than 1 meter long comes around once in a while for scraps of leftover pet food. If the cats had not raided the nests, I believe that the squirrels or the monitor lizard might have, sooner or later.

    By the way, the squirrels, which are attracted to the same things as the birds are in my garden, have learned to survive despite the cats, and there have been no casualties among their ranks in the last four years.

    I also actively encourage kingfishers, sunbirds, waterhens and various doves to visit, placing their feeding stations in open areas that do not allow cats to stalk them unobserved. So far, the cats have not managed to catch any of these.

    Yes, I believe staunchly in nature conservation, but am not overly sentimental about the need to preserve or rescue every single living thing, regardless of cost.

    • That is all well and good I suppose, but to conclude that the birds are stupid because they have not adapted to an introduced predator that you have seen fit to introduce into its territory is absolutely absurd. Your surety that your cats have not taken any other birds or lizards also seems wildly optimistic/unrealistic to me. By creating attractive places for birds to feed/nest, then filling them with an invasive predator, you are essentially creating an ecological trap. I think we can all be quite happy that you don’t have the privilege of hosting any CITES species at your place.

      “Birds learn to adapt” — how easily and succinctly you have completely dismissed the entire concept of invasive predators on bird populations. I am sure the hundreds of extinct island species, and the millions and millions of suburban birds across the world will be happy to know that there is no problem on this front — they just have to “adapt”. Brilliant. Thank you.

      Andy

  3. I had the same thoughts as Andy. You really need to keep the cats away from the nesting birds. They cannot co-exist together and the birds will not survive under these conditions. Please remove your cats from the nesting Yellow vented Bulbils.
    The birds want to nest there and the cats can clearly be put elsewhere.
    PLEASE protect these birds.
    Thank you
    Sandi

  4. Lee Chiu San

    Dear Sandi,

    I have no intention to cause unnecessary distress to you, the birds, or to some other visitors to this site. I have to apologise that I am now heavily involved in some work, but by the end of this week I intend to find the time to pen a detailed explanation as to why some losses, while regrettable, are not easily preventable.

    The death of nestlings is not something at any of us likes, but after reading my piece, I trust that you will understand why this sometimes happens.

    Hopefully, Prof. Wee, our web-master, will see fit to allow it to be posted.

  5. […] condemnation to a heartfelt appeal for me to help ensure that the next nesting is successful LINK. My discussions on the general price of birds in the trade drew flak, even though I believe that […]

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