I have placed a number of “man-made” bird nests at strategic locations in our farmhouse so that we can get those birds “friendly’ to humans to find good places to lay their eggs and raise their families.
Despite this initiative, some birds decide that these are not good enough and still choose to build their own, sometimes next to the ones I offered so I have realized that some birds’ thinking differ from mine!
So it was that a pair of Sayaca tanager (Thraupis sayaca), defined by my bird book as “tame” and inhabiting populated areas, decided to nest under our font verandah about four years ago. Luckily their breeding was successful and, eventually, young birds were seen leaving the nest. The same birds (although I am not sure that there were the same individuals) built another nest on top of the existing structure but the mummified remains of their offspring were the evidence of some kind of tragedy.
Last year, a pair of Saffron yellow finches(Sicalis flaveola), also keen on inhabited areas, added their own contribution to the already untidy grass mass and this year, the same bird species yet again completed the structure by adding more straw and deciding to breed there.
For the past couple of weeks the female had sat on the nest and the male was also seen nearby but not actually incubating and we did not observe any sign of hatchlings.
One afternoon, a couple of days ago, we returned from Salta town in mid afternoon after running some necessary errands there, and soon after arrival we heard loud shrills coming from the verandah. As expected my wife discerned what was happening. The nest was under the attack of a snake!
We knew that a snake lived on the roof of the house as it had been spotted sunning itself coiled and I had seen it slithering away by the side of the verandah. So there it was, its front end on the nest and its rear holding on to the roof timber.
The birds were mobbing the snake while chirping loudly and flying very close to the intruder but not actually pecking it (see videos below). However, they were clearly too small to have an impact on the aggressor and eventually they just perched nearby to watch the tragedy!
Our arrival and photographic efforts disturbed the action taking place and the snake started to abandon the nest and eventually slipped down the stem of a climbing plant and, once it got into the thick of the plant, it immediately change direction and climbed back towards the roof of the house where we lost sight of it. I am not yet sure of its identity.
While the snake was moving, I caught the sight of a bulge in its otherwise slim body that was a signal that the attack was successful and that it had either eaten the eggs or the nestlings. (confirm what it ate when the snake is identified). ALthough the parents remained for a short while next to the nest, they have now abandoned it, another indication that the young are no longer there.
We wait and see what happens next as the Saffron yellow finches are known to lay eggs throughout the year and they may try again on the same nest. As I told you earlier, I do not understand the way birds think!
Regret the video quality but things were happening very fast and we were lucky that my wife was ready with her phone to record it!