INTRODUCTION
Field observations are pertinent to the science of birdwatching. There's where all the primary data are collected and analysed by scientists. An understanding of nest-site behavior of birds could also provide valuable insights to conservationists on how they can develop conservation programmes on habitat requirements for cavity-nesters such as barbets, woodpeckers, hornbills and in this case Eurasian Tree Sparrow as well. Like humans, many species of animals do engage in some sort of courtship display with an ultimate aim of luring a suitable mate. Most of these courtship displays are performed by males as i have observed.
LITERATURE REVIEW
According to Melissa Mayntz (2019), the exact type of courtship displays can vary greatly between species. Even birds of the same species may also show different courtship variations in different regions. Generally the courtship behavior of birds can be divided into the following types (Melissa Mayntz, 2019):
i) By way of singing - occurs in many bird species. I have also learnt that some native tribes in China and Africa do sing as well to attract his female partner. If the female partner sings back, the chances of marrying her will be very high indeed.
ii) By way of dancing - remember the bird which does the "moon walk" in Papua or the long-tailed widow bird which jumps up and down. Thank God i do not need to do this.
iii) By way of display - like the magnificent Tragopan, Great Argus, the Indian Peacock, Mountain Peacock Peasant etc.
iv) By way of preening - i have seen this behavior especially among the parrot species.
v) By way of feeding - this behavior will be highlighted in this report.
vi) By way of nest building - like the bower bird.
I was very fortunate to have witnessed the affectionate courtship behavior of a Coppersmith Barbet (Megalaima haemacephala indica) leading to their nest excavation activity. At the same time the Eurasian Tree Sparrow (Passer montanus malaccensis) were there as well to share some moments of their nesting behavior.
STUDY AREA
An old and half dead durian tree located in a small wooded area close to human habitation. Note: this same old abandoned durian tree has been successfully used many times by the coppersmith barbet to raise their offsprings.
FIELD OBSERVATION
Observation was only carried out for a day from 9.30am (in the case of the Eurasian Tree Sparrow) and around noon for the Coppersmith Barbet. I will start with the courtship behavior of the Coppersmith Barbet.
As i sat down under a shaddy rambutan tree not too far away, i noticed a male Coppersmith Barbet (above) flew in with a big fruit (which i presumed was a fig) in between its bill.
The male Coppersmith Babbet then proceeded to give the fruit to the female.
which she has gracefully accepted.
Not satisfied she requested for the last remaining bits.
Once done she asked whether he could get more but the male bird told her that nope ! its time to get to "work" !
So she flew down to check on a cavity.
Before entering she checked its surrounding.
Once clear she enter the nest cavity. At this point i was thinking that there could be some nestling (s) inside.
Holy Smoke ! to my huge surprise she was actually excavating the cavity. While this cavity excavation work took center stage, the male bird was no where to be seen. Perhaps he went to look for more figs ?
This is probably the first documentary proof that a female coppersmith barbet has to do all the hard work in nest building and as well as egg laying. Fortunately both parents took part in feeding the nestlings as reported in my earlier post back in February 2013. Otherwise she probably would have proceeded to file a divorce paper.
At the same time i have been observing several Eurasian Tree Sparrow (ETS) which have gathered around on the same durian tree in the morning. Then i noticed one of them was having something on its bill.
It looks like a seed or perhaps a piece of a bread.
It then flew up to a trunk. That was when i noticed that it was using an abandoned cavity and it was an active nest !
A view from another angle.
You can see that the food item was still on its bill.
Making sure the fledgling gets the food correctly.
The ETS then proceeded to give it to the nearest fledgling.
Then the ETS tried again and again. The nestlings were fed regularly at 5 - 10 minutes intervals.
At one time the ETS (not sure whether it was the same ETS) was also seen discarding feces of the nestlings as shown by the photo below.
The ETS did not drop the feces below the nesting cavity but instead it took it further away,
DISCUSSION
Many birds species have placed their nest in cryptic / out-of-reach sites to avoid predation. Nesting inside isolated host trees is one of them. The host tree in this case was an old durian tree of about 30 meters high. The Coppersmith Barbet's nest was about 15 feet from the ground while the ETS cavity was slightly higher at about 20 feet. See the tree illustration below.
Although studies have reported that higher cavities may be difficult for predators to detect the audible sound of begging nestlings but it appears that the Eurasian Tree Sparrow (ETS) in this case may have just been an opportunist secondary-cavity nesters i.e using the decayed trunk as an ephemeral nesting resource.
The cavity nest of the Coppersmith Barbet meanwhile was freshly dug-out with a typically round/oval shape entrance.
The above examples have also provided the following intriguing facts:
i) that different species of cavity nesting passerine have no qualms of sharing the same tree for their breeding activities.
ii) that a female Coppersmith Barbet does assist in nest building activities as well.
Although this brief and limited observation may not qualify as a scientific report but i believe it has provided some fascinating insights of the courtship and nesting behavior of a Coppersmith Barbet and the Eurasian Tree Sparrow.
References:
https://www.thespruce.com/bird-courtship-behavior-386714
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Science is not all about new discoveries. Sometimes it can just be about refining a simple technique such as the techniques to detect so-called exoplanets which was researched by Michel Mayor, a Swiss Nobel Prize winner 2019 for Physics.