WM James Davis[SMTP:
>Interesting observations. Can you be more specific about the
>different
>types of alarm calls.
>Can you identify if local habitat differences between the two
>populations
>of N. Miners? Perhaps, your chickens are better at spotting >the
hawks and
>beat the Miners to the task. I assume that the N. Miners >chime in
when
>they also spotted the intruder. Do they, or are they using >your
chicken
>as sintinels?
I am not in any doubt that the alarm for terrestrial threats (or
perceived threats, since they will often alarm at the appearance of
humans) differs from that for aerial ones. The alarm for birds of prey
is a one note call , short and sharp, repeated rapidly. In hindsight,
I am leaning to the theory that the difference in alarms for different
aerial species may be more related to the urgency of the threat, e.g.
when the local Hobbies come past they do so at relatively low altitude
and high speed, the alarm is then very rapid, almost staccato.
Similarly for a Brown Goshawk which occasionally flies through the
area. Wedge-tailed Eagles and Whistling Kites, even sometimes
Peregrines, usually come over at a higher altitude and lower speed and
the alarm is correspondingly less rapid. Alarm calls for terrestrial
threats are more 'squawky' (sorry, can't describe it any better than
that but my ear/brain knows the difference). When Pacific Bazas are
about the alarms are cacophonous and accompanied by a lot of flying
about and mobbing of the intruder, aided by their commensals, the Grey
Butcherbirds.
This applies only to the Newcastle Uni population of Noisy Miners
which is a sedentary population that has been in residence for in
excess of fifteen years, occupying something like 3-5 sq km or more.
The Miners in the vicinity of my home are far fewer in number and roam
slowly over an area of tens of sq km. Possibly their failure to
adequately alert me to the presence of BoPs is a result of fewer pairs
of eyes and less time spent within my hearing. I have not noticed any
species differentiation in the alarm calls of this group of Miners.
>>When the Miners left the immediate vicinity of
>> our home, we were invaded by Yelow-rumped Thornbills, >>Speckled
Warblers,
>> Superb Blue Wrens, Yellow-faced and Brown-headed >>Honeyeaters,
Spinebills
> >etc. etc.
>What time of year?
This would have been around July/August of 1996.
>I am confused. I wasn't aware that N. Miners (as oppose to >Bell
Miners)
>also farm lerps.
>Cheers, Jim Davis
No, well perhaps I've got that bit wrong. Maybe someone else can
verify or contradict what was basically a supposition on my part.
Regards
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