G'day David, Mike & everyone else Thanks for your comments on this. I think
that it is important to note that this observation was made in the twilight of
dusk (6:30pm), so it would I think be considered a normal time for this species
to be up & about foraging. It would also be more correct to consider this as
crepuscular activity, rather than diural versus nocturnal. Was the direct
flight pattern significant in determinig that the birds were actually
migrating? I have only seen this species on migration once before & this was a
southward movement along the shores of Little Ramsay Bay on Hinchinbrook Is,
when there were some 10 birds or so, at a similar height to yesterday's.
However the birds on this occasion were more or less in single file.Last night
I thought the first 3 birds grouped together in a triangular line was very odd.
I have been outside tonight to check for other birds coming through, but none
were seen here. Do we agree that this sighting was of birds on a mig
ration flight? I just don't know, but they weren't in the normal foraging
flight that I am much more used to seeing around here in late October with
WTNJ's. My experience with migrating nightjars is very limited, so I am
interested in what others think about this. David, I concur with you about WTNJ
on the coastal lowlands being strictly passage migrants only. The only birds I
have seen on the lowlands have been from mid-Sept to late October & in
March-April. I see birds outside these times only at various places on the
local tablelands (ie Julatten, Davies Ck etc). Cheers for now Martin
CachardCairns0428 782 808
Date: Sat, 22 Oct 2011 01:20:56 -0700
From:
Subject: White-throated Nightjars on migration in Cairns
To: ; ;
Hi Martin and Mike,
Observations of diurnal migration in WTNJ do not necessarily preclude nocturnal
migration as well. When I was in Townsville migrating nightjars would sometimes
turn up in unusual or unexpected day roosts. The huge railway workshop sheds at
Stuart was one "regular" location. I flushed 1 from my chicken coup in a
suburban backyard one morning. Whilst I can't prove it, it seemed like they
were arriving at these locations during the night to roost by day, before
moving on. It appears that they are only passage migrants around Townsville
(and I think the entire NQ coastal lowlands), though I never recorded them in
migration flight, day or night. WTNJ should be back in SE Aust in numbers by
now.
David James,
Sydney
==============================
From: Mike Carter <>
To: martin cachard <>; birding-aus threads
<>
Sent: Saturday, 22 October 2011 4:23 PM
Subject: White-throated Nightjars on migration in Cairns
Very interesting as this sighting would possibly be nocturnal migration. In
Carter, M., & Bright, B. (2011), 'White-throated Nightjar: Diurnal Over-sea
Migration in
a Nocturnal Bird' Australian Field Ornithology, 28; 32-37, published in March
this year we presented evidence for diurnal migration in this species.
I suppose your birds could have just been arriving at their destination or
continuing their journey.
Mike Carter
30 Canadian Bay Road
Mount Eliza VIC 3930
Tel (03) 9787 7136
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