Cooper's Hawk in nest at Maplewood Park
Outdoor Ontario

Cooper's Hawk in nest at Maplewood Park

ostrich

  • Old Timer
  • *****
    • Posts: 56
I dropped by the nest a little after 5 pm,  and shortly after I arrived there the male flew into the nest from the opposite direction (i.e. from the opposite direction if you were walking toward the nest from Glen Erin).  I could see he was carrying almost certainly some kind of prey item in his talons (most likely some kind of deplumed passerine).  He landed in the nest with it and left almost immediately.  Further indications that he dropped off something were clear when the female then stood at the edge of the nest rim and was reaching down into the nest and making head and neck movements that would have been pulling at a food item.  Unfortunately with the impossibility of seeing into the bowl from the ground what I couldn't directly see is what she was doing with the pieces (i.e consuming them herself or offering them to a hatched eyas).  She was doing this for a period of 5-10 min.  

   This is, as we say, where the plot thickens...after presumably completing work on the food item,  the female then flew off the nest and went off into the trees (couldn't keep track of exactly where she went).  This was a bit surprising to me - it reminded me of what my female used to do last year after consuming a provided food item - she would usually feak on the tree branches, and would then invariably fly into a particular stand of pine trees before returning to the nest (to do what I don't know).  If she was feeding an eyas and not consuming the prey herself I'm not sure why she would have left the nest.  It's at this point I kind of lost track of who was where while walking around - a few minutes later an adult was back on the nest,  but I don't know whether the female returned while I was looking around or whether the male switched off.  

   So this certainly looks fairly promising - until young can actually be seen it's probably impossible to be 100% sure of anything - theoretically the female could have been consuming the prey herself - but if so this pair are different than mine last year - with mine the female would always take food deliveries from the male for her off the nest (typically the male would land in a nearby tree and make a very short 'chip chip' beckoning call,  at which point the female would fly off the nest and take the item, and consume it).
« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


Bird Brain

  • Frequent Users
  • Old Timer
  • *****
    • Posts: 2451
    • http://www.spnc.ca/
Hi ostrich.  I was there this afternoon and the female was sitting in the nest.  That's about it.  At the time, it was rainy weather.
« Last Edit: December 31, 1969, 07:00:00 PM by Bird Brain »
Jo-Anne :)

"If what you see by the eye doesn't please you, then close your eyes and see from the heart".


ostrich

  • Old Timer
  • *****
    • Posts: 56
Quote from: "Cody"
Do you have any tips to finding a Coopers nest?  I know I have Red-tails, Turkey Vultures and Coopers nesting very close to my house but I cant find the nest. It is very hard to because there is no trail that goes to where I suspect the nests are.


   Cody,

  I don't know much about TV nests,  but it will be harder (but certainly far from impossible) to locate an active nest now that the foliage has come in on the trees and we're well into spring.  A really good time to go looking is early in the spring before any leaves have come in - existing nests or ones under construction will jump out from far away.  I know of an active red-tail nest near me that can be seen literally from km away during the winter,  but now you'd be really hard pressed to realize it's there.  

   I've come across some references that suggest Coopers tend to switch nest trees frequently - I don't know how true it is.  For Coopers,  you're looking for a stick nest that will be maybe about 40-60ft high usually (I'm guessing the one in Maplewood Park is about 50 ft up or so) - I would expect to find it in among a treed area (i.e. less likely in an isolated tree out in the open).  Of course in urban areas what can be considered to constitute "treed" is somewhat different.   I don't think they would build out along branches very often - much more likely to find the nest built into a crotch or spot partway up the trunk,  where several branches come together to form a V.  If you look at the Maplewood nest,  it is this classic type.

   RT nests would have a lot of similarities to the Coopers nests,  but will be much much bigger.  I would expect RTs to build more on the edges of a wooded area though - in the interior of a woods would be less likely.  RTs in particular like at least one wide open path into the nest without branches or leaves in the way - the nest placement will reflect that.
« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


ostrich

  • Old Timer
  • *****
    • Posts: 56
Quote from: "Bird Brain"
Hi ostrich.  I was there this afternoon and the female was sitting in the nest.  That's about it.  At the time, it was rainy weather.


   Yes I would imagine hunting and other activity would probably be lessened during inclement conditions - I don't really do a lot of general birdwatching of the common songbird/passerine species,  so I'm not sure when their activity would be greatest.  I'm guessing that it would be most likely to see prey deliveries whenever those birds are either becoming active/foraging,  or perhaps when they would be tending to leave or return from roosting areas (accipiters like Coopers hawks like to surprise their prey and pursue them especially though wooded stands of trees and foliage)?  Those of you who know the local passerines and the neighbourhood really well might be able to take some educated guesses at that.  

   This is all what makes observing these birds interesting - these patterns of behaviour are far beyond what you can find in basic references and facts about the species.  I have only been able to observe one pair through only part of the process,  so even experience gained from one pair of individuals may not always translate to another.  I do think seeing food come to the nest is a stronger sign,  especially if this keeps happening.
« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


Bird Brain

  • Frequent Users
  • Old Timer
  • *****
    • Posts: 2451
    • http://www.spnc.ca/
Hi everyone.

Monday morning:  female Hawk standing on rim of nest, looking down and around inside the nest.  Behaviour/body language that followed:  regurgitating.  She then hopped down into the nest and was tilting forward a couple of spots inside the nest.  Feeding babies?

 :D
« Last Edit: December 31, 1969, 07:00:00 PM by Bird Brain »
Jo-Anne :)

"If what you see by the eye doesn't please you, then close your eyes and see from the heart".


ostrich

  • Old Timer
  • *****
    • Posts: 56
Quote from: "Bird Brain"
Hi everyone.

Monday morning:  female Hawk standing on rim of nest, looking down and around inside the nest.  Behaviour/body language that followed:  regurgitating.  She then hopped down into the nest and was tilting forward a couple of spots inside the nest.  Feeding babies?

 :D


   Bird Brain,  

   Accipiters (and raptors in general) do not feed young by regurgitation of already consumed food,  so this couldn't have been what the adult was doing.  If it looked like the adult was "gagging" or "retching",  it is possible it was doing what is termed casting,  which is egesting indigestible parts (hair, etc) of food the adult had previously consumed. I would expect the adult wouldn't allow the casting to go into the nest though.  

   The adults will be feeding any young food directly off prey items brought to the nest - for Coopers I don't know for sure whether they would be generally be feeding everything that is brought in immediately on delivery,  or whether they might keep leftover unconsumed prey and feed from these items at later times (I have seen that on other raptor nests - eagles do this extensively for example).  In either case though you should see indications of the adult pulling small pieces from the food item in order to provide them to the young (at the age they would be the eyasses would be unable to rip/tear prey themselves).  

   I got to the nest this morning about 8am (I was actually hoping to get there really early close to dawn,  but I didn't succeed in that).  The female was up and standing/preening for quite a bit of the time that I was there,  but there were no deliveries of food during that time.  Even when she was sitting though,  she seemed to be sitting noticeably higher in the nest that I have seen previously (I could consistently see her head and frequently her eyes above the edge of the nest rim,  which you couldn't see a week ago).  That might be an indication of a different sitting position,  and an interesting indicator.  Only continuing to watch and wait will tell.
« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


Bird Brain

  • Frequent Users
  • Old Timer
  • *****
    • Posts: 2451
    • http://www.spnc.ca/
Quote from: "ostrich"
If it looked like the adult was "gagging" or "retching"
Yes, that's exactly what it looked like - first time I've seen her doing this behaviour.  

Jo-Anne
« Last Edit: December 31, 1969, 07:00:00 PM by Bird Brain »
Jo-Anne :)

"If what you see by the eye doesn't please you, then close your eyes and see from the heart".


ostrich

  • Old Timer
  • *****
    • Posts: 56
That would be casting then.  If you've ever seen pictures of owl castings then these ones would be similar although owls tend to cast a lot more than hawks of this kind I think,  because owls tend to swallow whole while the hawks rip tear most of the prey into smaller pieces.  Accipiters I imagine would also tend to not have to cast as often because they usually completely deplume or de-fur their prey before bringing them to the nest or consuming them.  If you're walking around the park and the surrounding area,  you may keep your eyes open for a "butcher's block" - this is often a branch or tree stump where they will deplume prey - the presence of a lot of feathers and other similar remains on the ground may indicate such a spot.  I don't think it necessarily has to be nearby the nest though.
« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


Bird Brain

  • Frequent Users
  • Old Timer
  • *****
    • Posts: 2451
    • http://www.spnc.ca/
Hi everyone.  This afternoon, the female hawk is sitting very high up in the nest plus looking down and around in the nest quite often.  All of a sudden, she spotted me and was giving MAJOR Evil Eye!   :shock:   Decided to walk further along the paved trail and focus on butterflies and dragonflies for awhile.

ostrich ... I will keep my eyes open for a "butcher's block"!  

Jo-Anne  :)
« Last Edit: December 31, 1969, 07:00:00 PM by Bird Brain »
Jo-Anne :)

"If what you see by the eye doesn't please you, then close your eyes and see from the heart".


Cody

  • Old Timer
  • *****
    • Posts: 681
Quote from: "ostrich"
Quote from: "Cody"
Do you have any tips to finding a Coopers nest?  I know I have Red-tails, Turkey Vultures and Coopers nesting very close to my house but I cant find the nest. It is very hard to because there is no trail that goes to where I suspect the nests are.

   Cody,

  I don't know much about TV nests,  but it will be harder (but certainly far from impossible) to locate an active nest now that the foliage has come in on the trees and we're well into spring.  A really good time to go looking is early in the spring before any leaves have come in - existing nests or ones under construction will jump out from far away.  I know of an active red-tail nest near me that can be seen literally from km away during the winter,  but now you'd be really hard pressed to realize it's there.  

   I've come across some references that suggest Coopers tend to switch nest trees frequently - I don't know how true it is.  For Coopers,  you're looking for a stick nest that will be maybe about 40-60ft high usually (I'm guessing the one in Maplewood Park is about 50 ft up or so) - I would expect to find it in among a treed area (i.e. less likely in an isolated tree out in the open).  Of course in urban areas what can be considered to constitute "treed" is somewhat different.   I don't think they would build out along branches very often - much more likely to find the nest built into a crotch or spot partway up the trunk,  where several branches come together to form a V.  If you look at the Maplewood nest,  it is this classic type.

   RT nests would have a lot of similarities to the Coopers nests,  but will be much much bigger.  I would expect RTs to build more on the edges of a wooded area though - in the interior of a woods would be less likely.  RTs in particular like at least one wide open path into the nest without branches or leaves in the way - the nest placement will reflect that.



Thanks for the information!
« Last Edit: December 31, 1969, 07:00:00 PM by Cody »


ostrich

  • Old Timer
  • *****
    • Posts: 56
I was at the nest last night at about 7pm for about 45 min - nothing other than female sitting,  but she is sitting high all the time now.
« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


Bird Brain

  • Frequent Users
  • Old Timer
  • *****
    • Posts: 2451
    • http://www.spnc.ca/
Saturday, 1-2pm:  female hawk sitting very high in nest.  All of a sudden, she got up, was tearing at something then tilting down into the nest focused on a couple of specific spots.  It struck me that this appeared to be a feeding behaviour but still can't see the babies!  At one point, thought I saw a head - but, No ... it was a leaf!   :lol:   (darn it, I was so excited!)  Female hawk was then standing upright in nest, looking down and around in the nest quite quickly as if following some sort of movement.  

:D
« Last Edit: December 31, 1969, 07:00:00 PM by Bird Brain »
Jo-Anne :)

"If what you see by the eye doesn't please you, then close your eyes and see from the heart".


Cody

  • Old Timer
  • *****
    • Posts: 681
Good luck finding the young!
« Last Edit: December 31, 1969, 07:00:00 PM by Cody »


ostrich

  • Old Timer
  • *****
    • Posts: 56
What you are describing is certainly very consistent with feeding of young - that is exactly how they would be doing so at this stage.  Based on everything that's been seen and reported,  I'm pretty confident there are young in there - only waiting and watching for a sighting will confirm 100%.  It might take some time before they can be seen though - it's hard to say how deep that nest bowl is,  but it could be quite deep.  

  I'm not sure to what degree posting images is okay here,  but I'll post a couple of shots I took of the female a few days back.  If these are too large I can post smaller versions:  



« Last Edit: December 31, 1969, 07:00:00 PM by ostrich »


Bird Brain

  • Frequent Users
  • Old Timer
  • *****
    • Posts: 2451
    • http://www.spnc.ca/
ostrich ... great photos!!!  :D

I was looking at the nest long and hard on Saturday to the point my eyes and neck were getting sore.   :shock:

One of these days, we will see the babies!  

Jo-Anne  :)
« Last Edit: December 31, 1969, 07:00:00 PM by Bird Brain »
Jo-Anne :)

"If what you see by the eye doesn't please you, then close your eyes and see from the heart".