Hi Charles,
Yes, radio-transmitters do eventually fall off birds, but usually researchers
try to recapture birds before the battery runs flat so that the transmitter can
be retrieved and used again. There are two main ways that radio-transmitters
are carried by small or smallish birds - they are either glued to a gauze patch
that has been glued with Vetbond (a glue used by vets for sealing small animal
wounds or incisions) to the base of clipped feathers on the upper back or
carried as a harness as a backpack. The harnesses are usually designed so that
the straps break or snap shortly after the life of the transmitter battery has
expired, thus freeing the harness from the bird. Glued transmitters also tend
to fall off the bird after the same time interval. The main limiting factor is
the weight of the transmitter and battery pack. The general rule of thumb is
that a bird shouldn't carry anything that is more than 5% of its body weight.
Technology in recent years has made these packs smaller and lighter, so they
are being used on increasingly smaller bird species. In the 1990s we put
radio-transmitters on Spinifexbirds on Barrow Island in WA, which at the time,
was a species at the lower end of the weight limit that could carry
transmitter-battery packs, but I've heard of smaller birds carrying
transmitters since then. I suspect Steve Murphy will be experiencing similar
challenges to what we faced when we used transmitters on the Spinifexbirds
since both species inhabit dense Spinifex clumps. We found that the length of
the transmitter's antenna had to be relatively short and running parallel to
the bird's back to prevent it snagging on spinifex branches. If the antenna
snags on a spinifex clump it is pulled off the bird, rather than the bird being
trapped.
Kind regards,
Stephen
Stephen Ambrose
Ryde NSW
-----Original Message-----
From: Birding-Aus On Behalf Of
Charles Hunter
Sent: Tuesday, 11 August 2015 7:59 AM
To: SeanDooley; 'Peter Shute'; 'Tony Palliser'; 'david taylor'; 'Murray Lord';
'birding-aus'
Subject: Night Parrot captured and videoed
Sean, do radio transmitters naturally fall off? I understand from the 7.30
Report last night (10.08.2015) that the small battery lasts 21 days.
Keen to know if the birds (perhaps inconveniently) "hop" around with a wire for
several months. Cheers,Charles
From: SeanDooley <>
To: 'Peter Shute' <>; 'Tony Palliser' <>;
'david taylor' <>; 'Murray Lord'
<>; 'birding-aus' <>
Sent: Monday, 10 August 2015, 23:28
Subject: Re: [Birding-Aus] Night Parrot captured and videoed
Hi Peter and all who have posted on this topic.
Just to let you know, Dr Steve Murphy is writing a piece for the upcoming
September issue of Australian Birdlife outlining the progress of much of the
research that has been going on at the site of John Young's initial discovery.
Without wanting to pre-empt Steve's article, the draft that I have seen has
some pretty impressive results. Being able to attach the radio transmitter,
(even for the few weeks it was operational) has enabled the researchers to
probably learn as much about the ecology and behaviour of Night Parrots as we
had learnt in the previous 150 years.
As to the 50-250 population quoted, I suspect that comes from the Recovery Team
estimates of the entire population. Steve's article will tell us that there are
multiple birds at the site but nowhere near 50 for that location.
And to Paul Dodd, I have to confess that on an interview I did with ABC News
24 today, I think I may have used the phrase "hordes of birdwatchers" who would
want to see these birds! While personally I think the threat of birders
adversely impacting Night Parrots while trying to twitch them is probably
pretty low- certainly far less of a risk than that posed by wildlife smugglers-
I still believe it is wise to keep the location secret for as long as possible.
We can't afford to place these precious birds in jeopardy and we still don't
know enough about them to be able to safely say they could withstand even a few
birders searching for them in their home territories.
And no, I am not one of the lucky ones to have been out to the site. Nor do I
have the faintest idea where it is, aside from somewhere in Queensland!
Cheers, Sean
-----Original Message-----
From: Birding-Aus On Behalf Of
Peter Shute
Sent: Monday, 10 August 2015 11:51 AM
To: 'Tony Palliser'; 'david taylor'; 'Murray Lord'; 'birding-aus'
Subject: Night Parrot captured and videoed
It's not clear whether they're referring to the local population or the
national population. Surely there couldn't be even 50 locally, but a population
as low as 250 nationally isn't good news, let alone 50.
Peter Shute
> -----Original Message-----
> From: Birding-Aus
> On Behalf Of Tony
> Palliser
> Sent: Monday, 10 August 2015 10:49 AM
> To: 'david taylor'; 'Murray Lord'; 'birding-aus'
> Subject: Re: [Birding-Aus] Night Parrot captured and videoed
>
>
> When reading through the article the following sentence really caught
> my eye " Dr Murphy hopes the next round of netting will attract new
> members of the population which could be made up of anywhere between
> 50 and 250 birds. He is looking at new technology to track the birds
> via Bluetooth".
> I am baffled as to how the numbers are calculated - are there really
> that many there now? Certainly sounds most encouraging indeed.
<HR>
<BR> Birding-Aus mailing list
<BR>
<BR> To change settings or unsubscribe visit:
<BR> http://birding-aus.org/mailman/listinfo/birding-aus_birding-aus.org
</HR>
<HR>
<BR> Birding-Aus mailing list
<BR>
<BR> To change settings or unsubscribe visit:
<BR> http://birding-aus.org/mailman/listinfo/birding-aus_birding-aus.org
</HR>
<HR>
<BR> Birding-Aus mailing list
<BR>
<BR> To change settings or unsubscribe visit:
<BR> http://birding-aus.org/mailman/listinfo/birding-aus_birding-aus.org
</HR>
<HR>
<BR> Birding-Aus mailing list
<BR>
<BR> To change settings or unsubscribe visit:
<BR> http://birding-aus.org/mailman/listinfo/birding-aus_birding-aus.org
</HR>
|