[CT Birds] Bald Eagles vrs Great Cormorants

Glenn Williams gswilliams9 at yahoo.com
Tue Feb 23 14:31:15 EST 2010


Bill,

In both cases, the Great Cormorants were not holding fish, just going about their business.  It seemed that the intent was to kill the cormorant though I guess the possibility of trying to get the cormorant to regurgitate food cannot be ruled out. Neither my wife nor I could recall seeing a Bald Eagle going after something so big.

Glenn Williams
Mystic  

--- On Tue, 2/23/10, Boletebill <boletebill at yahoo.com> wrote:

> From: Boletebill <boletebill at yahoo.com>
> Subject: Re: [CT Birds] Bald Eagles vrs Great Cormorants
> To: ctbirds at lists.ctbirding.org, "Glenn Williams" <gswilliams9 at yahoo.com>
> Date: Tuesday, February 23, 2010, 12:45 PM
> Thanks Glen for your
> observation
>  
> This is really interesting. For years we've seen
> Bald Eagles diving on great Cormorants when they surface
> holding a large fish to swallow. I always assumed when I saw
> an eagle dive on a GC in the water that the eagle was trying
> to make the Cormorant give up a captured fish.  I
> don't assume this any more.
>  
> So it would appear that those water-logged feathers
> that allow Cormorants to dive deeper than other birds have
> their drawbacks...like a slow take-off after fishing...and
> BE's have tuned in to that drawback.
>  
> Bill Yule
> 
> "For those who hunger after the earthly excrescences
> called mushrooms."
> 
> --- On Tue, 2/23/10, Glenn Williams
> <gswilliams9 at yahoo.com> wrote:
> 
> 
> From: Glenn Williams <gswilliams9 at yahoo.com>
> Subject: Re: [CT Birds] Bald Eagles vrs Great Cormorants
> To: ctbirds at lists.ctbirding.org, "Boletebill"
> <boletebill at yahoo.com>
> Date: Tuesday, February 23, 2010, 12:20 PM
> 
> 
> Bill,
> 
> This past week while birding the Connecticu River from Eli
> Ferry Road to Gillette's Castle, my family and I watched
> a sub-adult Bald Eagle attempt to take a Great Cormorant on
> the water and later two sub-adults doing the same thing at a
> location further north.
> 
> Glenn Williams
> Mystic
> 
> --- On Mon, 2/22/10, Boletebill <boletebill at yahoo.com>
> wrote:
> 
> > From: Boletebill <boletebill at yahoo.com>
> > Subject: [CT Birds] Bald Eagles vrs Great Cormorants
> > To: ctbirds at lists.ctbirding.org
> > Date: Monday, February 22,
>  2010, 9:04 PM
> > This is not a sighting report but an
> > observation.
> >  
> > As I reported Friday Great Cormorants turned up on
> the
> > lower CT River in visible numbers suddenly after an
> almost
> > total absence earlier.  This weekend 30-40
> GC's were in
> > their usual haunts between Essex and Deep River.
> >  
> > Greg had made reference to GC predation by Bald Eagles
> in
> > Maine so I looked into that report and the article
> was
> > highly publicized and sensationalized but it looked as
> if
> > there was something significant going on there. It
> seems as
> > if BE's are flying out to offshore breeding
> colonies of GC's
> > and preying on chicks.  What struck me the most
> about this
> > report was the quote by the interviewed biologist
> that
> > described the eagles as "THESE YOUNG EAGLES"
> are like
> > "thugs", etc. He seemed to be making a point
> that they
>  were
> > not ADULT eagles but sub-adult eagles. This
> description
> > struck a memory chord in me about an two incidents
> from last
> > year and something I saw this week.
> >  
> > Since Wednesday there's been a cohort... (I'm
> not sure this
> > is the right term but it sounds more professional
> that
> > "gang")...there's been a cohort of 6 or
> 7 sub-adult BE's on
> > the river between Hamburg Cove in Lyme and North Cove
> in
> > Essex.  They all hang out together and have been
> giving
> > great performances and interactions for the tour
> boats. On
> > Thursday and Friday there was still ice on North Cove
> and at
> > one point 5 of these birds were on the ice together
> eating a
> > large dark bird. I couldn't see what the bird was
> but it
> > brought me back to last year when there was a similar
> cohort
> > of 4 sub-adult BE's and twice, that is two
> separate
> > occasions, we saw all 4
>  sub-adult BE's eating an adult GC on
> > an ice floe. Clearly one or more of these young eagles
> had
> > killed the GC dragged it on the ice and ALL 4 were
> feeding
> > on it. This happened not once but twice. This has led
> me to
> > ponder whether or not there are records of
> co-operative
> > hunting among sub-adult BE's?
> >  Could it be that these "gangs" of
> young eagles, like
> > "thugs" in the words of the Maine biologist,
> are working
> > together to take down GC's?  I've never
> heard of anything
> > like this.  I've heard of this with Harris
> Hawks but not
> > with Bald Eagles. Fascinating stuff though.
> >  
> > I'd be interested if anyone has any ideas about
> this
> > possibility.
> >  
> > Thanks.
> > Bill Yule
> > Lyme, CT
> >  
> >  
> >  
> > 
> > "For those who hunger after the earthly
> excrescences called
> >
>  mushrooms."
> > 
> > 
> >       
> > _______________________________________________
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> > Association (COA) for the discussion of birds and
> birding in
> > Connecticut.
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> > 
> 
> 
> 
> 
> 
> 
>       


      




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