Russet-backed Oropendola Behavior (1 Viewer)

Hi, this summer I was studying Russet-back Oropendolas in the Peruvian Amazon and I noticed some odd behaviors I was wondering if anyone has any insight into.

1- On two different occasions (nearing the end of the nest-building season) all the birds (male + female) were in the nest tree. However, unlike usual, only one male was singing. All other birds seemed to be sitting attentively, without any male challengers (physical or vocal displays). Does anyone know if this behavior reflects that male's status as the dominant male of the flock? (Being that they live in colonies with harems)

2- Mid-way through July, after a colony seemed to be working ceaselessly on building their nests, they suddenly abandoned it. My partner and I sat in front of their tree from dawn til dusk multiple days in a row, and never saw them return. Any ideas on what may have prompted such a rapid departure?

Thanks!

Hi Daelatpton

I'm in close proximity on a daily basis to a colony of Chestnut headed Oropendolas here in Panama near the canal. They started building in December and suddenly abandoned the activity and disappeared for a month. At the time of their disappearance there was a pair of Caracaras fledging their young near by. When they had raised the youngster and vacated the area the Chestnut-headed reappeared and started building again.
I watch them every day and haven't noticed the behaviour you describe. I have noticed that more than two will work on one nest so am now wondering if the individuals lower down on the pecking order or perhaps offspring from the previous season are assisting with the building of nests other than their own. If that is so it might explain the listening behaviour you are observing. A vertical hierarchy perhaps similar to certain species of Sparrows. I'm just guessing on all this but the behaviour I'm observing is consistent every day.
Sorry I'm answering your question with wild guesses but either way it is very cool to watch.

As a side note within a ten minute walking distance of the Chestnut-headed colony is a colony of both Crested and Montezuma Oropendolas building in close proximity to each other and seemingly all getting along.
Cheers,
Bryan

daelatipton said:

2- Mid-way through July, after a colony seemed to be working ceaselessly on building their nests, they suddenly abandoned it. My partner and I sat in front of their tree from dawn til dusk multiple days in a row, and never saw them return. Any ideas on what may have prompted such a rapid departure?

Thanks!

Click to expand...

I've no experience of the species, but at a guess, discovery of the nests by a dangerous nest predator could trigger this.

PS welcome to Birdforum, and sorry you've had to wait so long for any responses!