Re: FW: [canberrabirds] Boobooks calling actively

[Martin Butterfield <>]

As McComas Taylor has commented on page 87 of the Atlas a key explanatory factor for the shape of the graph therein is the special night outings he organised to look for owls in the Brindabellas in November.  The basic rule of "more observer effort = more birds" seems to apply.

Martin Butterfield

http://franmart.blogspot.com.au/

On 24 February 2014 07:31, Geoffrey Dabb <> wrote:

>From Jerry Olsen  -

Well, not quite. Yes, there is a spike of autumn calling now, and males can
be quite aggressive with each other, even physically fight. Many females
have left for their winter home range and none we watched participated in
this autumn territoriality, except that some watched. There is a much bigger
pulse in calling around 1 September that peaks maybe in November/December.
The attached is nights heard calling but there is a good graph in Taylor and
COG (1992), the ACT Atlas, that shows calling frequency in cells in the ACT
for Boobooks. It shows a nice peak in November, then a little spike in
March, but autumn isn't the major time of calling no matter how you gather
the data, spring is.

Jerry

PS - Veerman (2002) page 95 has a similar graph for Boobooks, with a peak
Oct to Dec, then a smaller spike in March. This data seems to link more to
calling than sightings because main sightings would be are around January
when broods are out.

jerry

-----Original Message-----
From: Stuart Rae [
Sent: Sunday, 23 February 2014 1:40 PM
To: Denis Wilson
Cc: COG bird discussions
Subject: Boobooks calling actively

Hi Denis,

Sedentary owl species such as tawny owl, typically sort out their
territorial boundaries post breeding season, during the dispersal period of
the young birds of the year. Peak calling is actually during this time,
which is generally autumn. They do call again at onset of nesting but much
less. So as various local birds here are now in their autumn/winter mixed
flocks, the magpies are singing and the wattle-birds are making their
autumn/winter calls, I would regard your owl calling as part of autumn
territorial behaviour. I have heard them calling at this time before, I
heard one the other night, and thought nothing of it as it seemed normal,
familiar owl behaviour to me. Many species sort out their territories then,
even if they leave for winter quarters and come back they still have
dominance in spring. And any that can will remain throughout for as far as
territories are concerned, the holder usually has the advantage over
intruders.

We need to get out at night more.

Stuart

On 23 February 2014 09:29, Denis Wilson <> wrote:
> I live on the edge of the village of Robertson, surrounded by mostly
> cleared farmland, with Rainforest remnants around.
> Boobooks are not uncommon. I hear the occasional call, and would not
> normally comment upon it.
>
> However, last night, in light misting rain, at 10:30 PM a Boobook was
> calling actively. That was unusual.
>
> I wondered if this is possible breeding season activity?. It seemed
> early in the season, (to my ears).
>
> Denis Wilson
>
> Are you amongst Greg Hunt's "increasingly hysterical environmental
> activists"?
> If not, why not?
> The Great Barrier Reef decision of 31 January 2014 is a travesty.
>
> "The Nature of Robertson"
> www.peonyden.blogspot.com.au



--
Stuart Rae


http://sites.stuartrae.com/
http://stuartrae.blogspot.com/

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