defence dept kestrel etc

["Philip Veerman" <>]

I will reply to this on the basis that I don't know if anyone knows.

 

Is it well documented that the male removes the heads of prey before feeding his mate?  I don't know that it is documented that the male removes the heads of prey. I have not heard of it as a consistent thing. No doubt it happens sometimes. Maybe he takes that as his bit of the food. Certainly the two skinks that I watched the male Kestrel bring to the nest at Kambah (one 2 weeks ago that I wrote about and a very similar incident last week that I didn't write about), were not missing the head.

 

If so, have conclusions about clean nesting habits been reached?  Some raptors bring fresh green branches into the nest and one suggested possible benefit may be hygiene but I suspect not Kestrels (as falcons don't build nests). Otherwise it appears that most raptor nests get dirty, so cleanliness doesn't appear to be an important issue. But I don't see any connection of that to that the male removes the heads of prey.

 

How does a kestrel know what a glass screen means in terms of her own and nestlings safety?  We can't know what they know. I doubt that it does know. It probably notices it stops the weather but that is pure guess. It sees the building as providing a tall secure structure like a cliff face that is probably well protected from weather and predators.

 

Surely they must have to practise these behaviours to know they are safe from the humans?  Is being safe from humans the issue? It probably doesn't associate the building site with humans. It probably cares about being safe from snakes, goannas, etc. 

 

Where can I find answers to all my questions?  Penny Olsen's book "Australian Birds of Prey" is probably the best local source. I had a quick look at anything about nest cleanliness but did not find an answer in a flip through of a few minutes. It might be there.

 

On a related thing I'll copy in these messages below and add to it that the above book does describe this food caching behaviour (page 100-101) but apologies to Margaret, I had not noticed it until just now.

 

-----Original Message-----From: Margaret Leggoe [ Sent: Friday, 2 November 2012 9:17 AM    To: 'Philip Veerman';     Subject: RE: [canberrabirds] COG's bird blitz & Kestrel nest etc.

Philip,

I noticed that behaviour last year at “my” kestrels’ nest while Mum was still sitting on eggs.  She didn’t have the appetite to accept all the mice that Dad brought her and sometimes he would stuff around with it for up to an hour before hiding it in a crevice in a nearby tree.  These shots show Dad hiding a mouse in a fork.  From the time he went into the fork on one side and came out the other without the mouse was only 20 seconds.

Margaret

Thanks for that. I did not know they did that. Maybe other people have written about that. If so I don't recall it.

 

Philip

 

-----Original Message-----
From: jude hopwood [
Sent: Tuesday, 13 November 2012 5:53 AM
To: COG
Subject: [canberrabirds] defence dept kestrel

Dear All,

 

October 13th I posted info sent to me on a kestrel in Defence Central.  Her establishment of the 1 metre exclusion zone is clever.  Is it well documented that the male removes the heads of prey before feeding his mate?  If so, have conclusions about clean nesting habits been reached?  How does a kestrel know what a glass screen means in terms of her own and nestlings safety?  Surely they must have to practise these behaviours to know they are safe from the humans?  How long does this kind of learned behaviour take?  Where can I find answers to all my questions?  No info on hatching dates provided, sorry.

 

The mother kestrel had three eggs. She now has two hatchlings and we don't know what happened to the third egg.
As you can see she gives us some serial killer stares but isn't too fussed about us as long as we stay about a metre from the glass. The male is more jittery but he generally just delivers the food (why rip the heads off all the birds before delivery?) and goodies and she stays home and feeds the kids.

 

I'm sorry I can't post the photos.  I've tried to reduce the sizes but can't manage less than 176kB.

 

Jude