Glaslyn osprey project (GOP)

Friday, 9 May 2008 9.58

First chick due within a week

Posted by Wendy Johnson

With just a handful of days left before we expect the first chick to emerge in the Glaslyn nest, things are getting pretty exciting up here. 

Egg number one is expected to break open around the middle to end of next week.  From then on the two adults will really have to get busy.  The male will be bringing back plenty of fish so that his mate can feed the little one, whilst the female continues to incubate the remaining eggs.  The eggs will hatch in the order they were laid, a couple of days apart.

Hormonally, the female is aware that hatching is getting close.  Yesterday, she placed a piece of fish over the eggs, as if making the association beween her food and the eggs. She did this in the days prioir to hatching last year too.  She knows that pretty soon feeding the brood will be her number one priority.

Whilst the female takes on all of the incubation during the night, the male is once again playing a very active role in domestic responsibilities and takes over incubating for about half the time during daylight hours.  They have quite an established shift pattern and usually one bird will do a couple of hours on the eggs before the other will take over. 

Actually the male is a less efficient incubator than the female.  Perhaps it is because he is slightly smaller, so has less body heat and isn't able to quite cover the eggs fully.  Or, maybe it is because he does not have the brood patch of the female (this is a balder patch of feathers on the front where she can nuzzle the eggs close to her skin and ensure they gat the most body heat from her).  However, since the weather up here the last couple of days has been absolutely scorchio, the male has taken the chance to do more daytime incubation than ever, knowing that his less efficient incubating will be balanced out by the warm air temperature.

We still have a third osprey in the area.  A glut of visitors arrived just after 10am yesterday telling us they had seen an osprey fishing over the Dwyryd estuary.  We knew it couldn't be one of ours, as both our birds had been on, or within sight of, the nest all morning.  In fact the male had just brought back the biggest branch ever to add to the nest, and had inadvertently walloped his missus with it on delivery (we know he has a clumsy streak after his antics of previous years, we also know he has an obsession with bringing back inappropriately huge chunks of nesting material). 

So, this other osprey.  Male or female?  Well, we don't know.  No-one got a close enough look to tell.  But it seems unlikely that this osprey is still on migration - it's very late in the season now.  Could it be scouting its own breeding territory?  Could it even be one of the Glaslyn youngsters from 2005 or 2006?  We may find out more as the season goes on...