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3 November 2012

Grass Owl : breeding season well underway


The 1st November, I checked one Grass Owl's (more exactly Eastern Grass Owl Tyto longimembris) site along the Red River, not far from Hanoi. I found a breeding pair, with the nest located EXACTLY at the same place than the one of last year (in which they had successfully raised 5 chicks) ! This seasonnally flooded area is large, and they had many other possibilities but they chose to come back to the old place. Pretty amazing!

The second thing worth noting is that the nest already contain chicks, 5 at least (eldest one around 20 days). So, the breeding season started much earlier (c.1 month and half) than last year. If everything is OK, those chicks will leave the nest before Christmas ; last year, it was after the Têt (Vietnamese New Year) i.e. early February (for the youngest chicks). Fledging is at about 2 months.

This area was still flooded at the beginning of August. Considering the fact that the female started laying eggs in early September (incubation is thought to be around 42 days), this pair reoccupied the site very quickly - and the rodents also I guess !- after flood withdrawal. Where were those owls during the flooding season ? An interesting question...


The two adults were with the chicks. When I flushed them, one flew about 20 meters and landed. The other one (photos) turned few seconds around to look at the intruder - maybe the female.




The legs are very long compared with the Barn Owl ; an adaptation for hunting rodents in tall grass. In flight, the whole length of the toes extending beyond the tail feathers.


The nest is a simple platform of trampled grasses, well enveloped by the surrounding grass, with a semi-covered entrance + some tunnels - from where the adults sometimes escape when disturbed.
The youngest chick (less than 1 week old I think) is almost in the centre of the photo (only the head is visible).

Fire in a Grass Owl's site (november 2012). Human-caused fires are the main threat in my area. Farmers begin to burn grasses in October-November, sometimes for obscure reasons (not for cultivation).
Last year, one nest was destroyed by fire during the incubation.

2 comments:

  1. Fantastic photos...I also wonder where those owls go when the islands are under water...perhaps these are the "Barn Owls" that can sometimes be found hunting rats near West Lake...

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  2. Yes, next time I will spot Barn Owls in flight I will try to check the size of the legs... if I have my bins - but I rarely bring them at night ;)

    Sebastien

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