It has been a massive year for cicadas around Bellingen on the NSW mid north
coast. The din in the forest is maddening and bird-watching is nearly
impossible - in cicada-infested forests the birds don't call much, and don't
even seem to move around much. I wouldn't be surprised if they actively avoid,
in so far as they can, forests where the cicadas are deafening. Most of the
cicadas I have seen round here are big ones (Razor Grinders, Double Drummers,
Black Princes, Redeyes), which are maybe more difficult for birds to eat than
the smaller cicada species. I do sometimes see Drongos, Bowerbirds, Figbirds
etc. catching these big cicadas - but the process of eating them is clumsy and
often prolonged. The big softy juicy Bladder Cicadas, on the other hand, are a
favourite food of the Pacific Bazas in particular.
I think the long, prime-number based life cycles for which cicadas are famous
apply to overseas species. Max Moulds, the Australian cicada guru, writes in
his wonderful book Australian Cicadas: "the length of life cycle, which depends
on the time spent underground by the nymphal stage, is unknown except for two
grass species, which have annual life cycles." (mind you, that was in 1990)
Around Bellingen, the cicadas last summer were fairly quiet, while the two
summers before that were both very noisy. Most of our local species seem to
appear every year, though in wildly varying numbers.
Brian
-----Original Message-----
From:
On Behalf Of Ross Macfarlane
Sent: Sunday, 10 January 2010 12:10 PM
To: birding-aus
Subject: Bird irruptions and cicadas
Greetings all,
As has been widely discussed here, there have been a lot of irruptions of
different bird species in the southeast this past spring - rufous songlarks,
white-winged trillers, black tailed native hens, scarlet and black
honeyeaters come to mind. A couple of days ago my Dad mentioned something
he'd seen and I wondered if this was a widespread phenomenon, and if there
was a link. That is that he saw large numbers of woodswallows during the
spring - white-browed and masked - feeding on emergent cicadas in the Nyah
Forest, along the Murray River north of Swan Hill. Apparently even feeding
on the ground, which is unusual for them. Other birds taking advantage too,
such as straw-necked ibis.
Cicadas are known for having long, prime-number based life cycles (13 or 17
years; see http://kottke.org/09/08/cicadas-mating for example). I don't know
anything about the ecology of Australian ones, but could this past year have
been a cicada season, and could that have contributed (along with the spring
rains) to the bird irruptions? Interested to hear thoughts from anyone who
knows more about such things...
Cheers,
Ross Macfarlane
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Date: Sun, 10 Jan 2010 12:14:15 +1000
From: "Alan Gillanders" <>
Subject: Bird irruptions and cicadas
To: "Ross Macfarlane" <>, "birding-aus"
<>
Message-ID: <>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
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"Cicadas are known for having long, prime-number based life cycles"
G'day Ross et al,
I would love to hear from aan Australian entemologist on this.
Regards,
Alan
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