Well, Mark, as you asked, that is also true of my southern part of Gungahlin.
There are quite a few Koels along the Ginninderra Creek corridor and nearby
street trees. They were recognisable a few months ago by the iconic 'coo-ee'
call every dusk and early evening, quite constant for some weeks. But now that
you mention it, I recognise that of late I, like you, have not heard that call,
only the invariable and far-carrying 'wirra wirra' and its variants all night
every night. The Koels have thankfully not chosen a tree very close to me for
their night roost but a few doors up has a regular night roosting tree and the
folk there are quite irritated by that bird at night. I hear them distantly if
I wake. (which at my age I do). They move about at first light and are
sometimes near my house then, but that I suspect is luck more than any
particular Koel tree preference and the Magpies and Blackbirds etc have started
up by then anyway.
On 28/12/18, 5:28 pm, "Mark Clayton" <> wrote:
I won't get into the nesting of Koels and raptors but something that I
have noticed this year if that the male koel(s) in Kaleen are NOT giving
their typical, usual "coo-ee (or koel) call. I have only heard it twice
this season and then only very early when they first arrived. Both sexes
are giving their other regular calls, and a lot of funny calls that I
have not heard before. They are also NOT calling in the middle of the night.
Anyone else finding this? The birds were somewhat late in arriving in
Kaleen this year.
Mark
On 28/12/2018 4:55 pm, Philip Veerman wrote:
> Hi Con,
>
> As for the Channel-billed Cuckoo, its usual hosts are corvids and
currawongs, so along with the Collared Sparrowhawk shows the meat eating is not
a problem, even though the adults mostly eat fruit (and some meat). As for the
Koel, there is no raptor small enough.
>
> Here is that "quite a few" again. Let's suggest that means 5 raptors that
are smaller: Collared Sparrowhawk, two small kite species and kestrel & hobby.
I also suggest that most raptors have a far more aggressive and dangerous nest
defence than most passerines. Your last suggestion seems as good an additional
reason as any. Or a variant is that there are not enough raptors to go around
to maintain raptor-specific cuckoos. Either option would be hard to prove. Just
because there is not such a situation now does not mean it could never happen
or did never happen. Not all possibilities exist, at any one time. Which is
what I was hinting at before. Maybe over past millions of years they have tried
and been unsuccessful...... Who would know?
>
> You might also like to check out this variant:
https://www.treehugger.com/natural-sciences/cuckoos-and-crows-teach-us-how-parasites-can-be-good.html
>
> Philip
>
> -----Original Message-----
> From: Con Boekel
> Sent: Friday, 28 December, 2018 4:21 PM
> To:
> Subject: Re: [canberrabirds] Why don't cuckoos...
>
> I don't know the answer but the question intriques:
>
> In terms of size. the Channel-billed Cuckoo is larger than quite a few
> Australian raptores.
>
> In terms of diet, why not a meat-eating cuckoo?
>
> In terms of raptors predating/killing the cuckoo, current species of
> cuckoos routinely evade/avoid their hosts, why not evolve to be able to
> evade/avoid raptors?
>
> One possibility is that raptors are the highest trophic level and there
> is not enough energy to go around to maintain raptors AND
> raptor-specific cuckoos.
>
> regards
>
> Con
>
>
>
> On 12/28/2018 1:56 PM, Philip Veerman wrote:
>> Cuckoos parasitise species smaller than themselves. Maybe that is needed
to get the chicks the ability to push the host chicks out of the nest. So just
on that basis there is not much option to target raptors. I don't know if that
is the complete reason. That is not to suggest that this has always been the
case through history or will remain so into the future. One rare quoted example
though is that the Channel-billed Cuckoo has been recorded to parasitise the
Collared Sparrowhawk. Size difference still applies. All other examples I know
of include passerines.
>>
>> Philip
>>
>> -----Original Message-----
>> From: Con Boekel
>> Sent: Friday, 28 December, 2018 12:23 PM
>> To: canberrabirds chatline
>> Subject: [canberrabirds] Why don't cuckoos...
>>
>> Geoffrey's musings reminded me of a stray thought occasioned by the
>> larger than usual numbers of Koels lurking visually but not vocally in
>> Upper Turner this year.
>>
>> One sighting involved several Koels and a Collared Sparrowhawk in the
>> same tree at the same time.
>>
>> Here is my question: 'Why don't cuckoos parasitize raptores?'
>>
>> regards
>>
>> Con
>>
>>
>>
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