Monday, December 18, 2017

December 18, 2017: Great Blue Heron, nest building 101

Watching Great blue heron nest building. I'm looking for cues to identify when the male is near with a twig.  So far, the female seems to stretch her neck as a prelude for the male's appearance, but not every time.  I’ve found a very useful paper describing the behavior of Great Blue Herons

At this point, the female seems to be in charge of construction, with the male flying off to a convenient tree or vine, harvesting a small twig and returning to the nest.  He passes the twig to the female who then weaves it into the nest.  They have a short chat and he departs to repeat this action.  The images below illustrate various elements of this process.


My "Heron" tree.  There are three nests in this tree - one in the lower right (you can se the occupant), one in the middle (occupant mostly hidden) and a third nest above and behind this nest (the occupant is standing on top of a limb (perhaps waiting for a twig).


A discussion between male and female


Male bringing a twig for the nest


Male passing the twig to the female


Female grasps the twig in her bill


A neighbor


I'm not certain what this bill touching is all about - kissing?


Departing to search for another twig


Returning with a small twig


Returning with a large twig


Preparing to land and pass the twig


Bringing another twig


I've yet to capture how the male harvests twigs - but here is another episode of twig fetching


Bringing another twig


And another -  after all, you build a nest 1 twig at a time


I'm not sure what this is all about - perhaps two males in search of a female?


There is an interesting "dual of bills" between the male and female


Here one grabs the beak of the other


Flying away


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