Asian Pied Starling
Early last year Pied Starlings started building a nest in a young mango tree right beside our house. Sitting outside our front door I could watch the pair of them bringing in nesting material and creating a large ball of a nest that was quite well hidden but obvious thanks to all their activity.
However, I wasn’t the only one watching. Beside this mango tree is a taller tree with sparser leaves that was providing a perfect place for a female Asian Koel to loiter and keep an eye on what the Starlings were doing. Koels are a type of cuckoo common throughout Thailand. The Starlings seemed aware she was there and uncertain whether to keep going to the nest but they did anyway and basically sealed their own fate.
Female Asian Koel
Usually whenever I go near a tree with a Koel in it the bird will fly away very quickly but this one refused to. She was so intent on watching the Starlings that I could stand right underneath where she was perched, shout and wave my arms around but she would still ignore me. Usually I try not to get involved and just enjoy nature without judgement but I was feeling sorry for those Starlings having seen them already get brood-parasitised three times by Koels in the last two years.
I had little chance of actually seeing when the Koel slipped in to the Starlings’ nest but she inevitably did and after a few weeks’ waiting I started hearing distinctive screechy begging calls and caught a glimpse of an over-sized Koel chick. But it didn’t hang around long and over the course of a few days its call got further and further away.
I assumed it was just a single chick as previously all members of a brood had been a similar age and size but then noticed an adult Starling still occasionally visiting the nest with food so I climbed up the tree for a look. Sat on top of the nest was a very quiet, half-grown Koel chick looking much smaller than its departed sibling and not in particularly good condition. I left it alone and kept an eye on what happened.
My sympathies had definitely been with the Starlings up until that point but now there was an unexpected shift. It seemed like they were neglecting this chick presumably because they still had the demanding older one to look after somewhere else. Their nest visits were infrequent and the chick was far more subdued than I was used to. Seeing a youngster apparently suffering made me care about its welfare (whilst ignoring the welfare of all the small animals it was getting fed!). I was now on its side, reminding myself that it was not a parasite by choice. Fortunately, it never reached the point of considering re-fostering it myself, which, as I now know, probably would have been torture.
This carried on for the next week with occasional visits from the Starlings and the quiet chick hanging on. But it did keep growing and eventually moved into the tree from where its probable genetic mother had originally spied on the Starlings previously. It was still less active with much less insistent begging than the earlier chicks I had seen.
Asian Koel chick fresh out of the nest
Then, almost overnight it all changed and my sympathies switched back. Perhaps their early fostered chick was now independent because both Starlings suddenly seemed devoted to the task of looking after this one who they had largely been ignoring. And the chick reacted. How it reacted! It still didn’t travel far just hopping and flapping around the trees and bushes close to our house but it became extremely vocal as if trying to make up for lost time. It’s loud and irritating buzz-saw begging calls hardly paused throughout the day to the point where I was tempted to chase it further away from the house.
I resisted mainly because it was such a fantastic chance to watch what was going on. I got a real impression of what it must be like to foster a Koel chick and how that pair of Starlings worked so hard as if the only chance to stop the unbearable noise for a while was to stuff it full of food. I saw them bringing small frogs, large grubs and miscellaneous insects for the chick to gobble up. I had also left a bunch of bananas on the ground for the birds and tree-shrews to eat, and while they lasted that became the chick’s base. At one point the chick was perched right on top of the bananas screaming into the face of its parent who was shovelling banana into its gaping mouth. Occasionally the Starling would pause with a beak full of fruit as though unable to understand how the chick wasn’t full yet.
There was something a bit grotesque about the sight of this chick dwarfing the Starlings and screaming at them with its enormous red gape. Whatever food was brought was always quickly but very carefully put into the chick’s mouth as though the parent bird was slightly worried it might get swallowed too. What I hadn’t had the chance to see with earlier Koel chicks was how the begging call and gape comes with a rapid head-vibration and wing-quivering that really adds an impression that the hungry chick is feeling very distraught and in desperate need of more food urgently. To me it looked like stimulation to excess but it was very effective in driving the Starlings to keep working hard.
It was a relief to my ears when the chick finally started following its foster parents further afield and the buzz-saw noise faded away.
Those poor Starlings. Four times I’ve seen them nest and four times they have raised Koel chicks. Eight of them in total. And when it all starts again next year I will be thinking that it could be their own foster chicks returning to do the parasitising. Perhaps the most surprising thing is that Pied Starlings are still reasonably common in the area so they must be managing to raise their own chicks sometimes. I am hoping to witness it happening one day.
Then I had a realisation. I might be the cause of the Starlings getting done by Koels so often! It was me who planted the fruit trees and it's me who lets the wildlife have a decent share. So I am the one providing a perpetual feast of fruit for these birds and I have thereby ensured the garden is always full of healthy Koels ready to dump their eggs with any Starling couple unfortunate enough to choose to live here. My efforts to help the wildlife have wobbled the local balance! That makes me feel clumsy but I think it is still the right course.
And further away from our garden I have now seen Starlings with nests full of their own chicks. So that's a relief.
