well said Frank!!
& beautifully written too I might add...
cheers,
martin cachard,
cairns
> Date: Tue, 21 Oct 2014 20:42:53 +0800
> To:
> From:
> Subject: [Birding-Aus] Cannon Netting
>
>
> It still annoys me when I read criticisms of cannon netting.
>
> I have been a member of 15 or more AWSG North West Wader Expeditions
> over the past 20 years as a (paying) volunteer, and I certainly plan
> to join future expeditions when I am available. I am not a
> bander. I am not the one who summarises the data and publishes
> papers. But every expedition I see the dedication of the people who
> are involved full time on the study and conservation of
> shorebirds. I join each expedition as an assistant, often making the
> leg flags, as a spotter in the hide and often the leader of a process
> team. I learn more about shorebirds on every expedition that I
> join. The shorebird families are always high on my want to see list
> when I travel overseas.
>
> I have seen many important and useful outcomes from the expeditions.
> A few are :
>
> 1. Satellite Tracking of Bar-tailed Godwits. I admit that I was
> shocked when I understood how this was done. The waders are caught
> in cannon nets (this was not a significant threat and I was part of
> the team that made the catch), but then the birds were taken back to
> the Broome Bird Observatory where they were surgically implanted with
> the transmitters, with the aerial protruding from the tail. Surely
> this can't be good? Well all Bar-tailed Godwits survived and were
> released, transmitted their data for a year or more (until the
> battery gave up) giving important insights into the behaviour and
> movement of these birds (local movements, movements within WA,
> stopovers for some, feeding stopovers, breeding areas, post breeding
> areas), and they were all back in Broome the next year. This was
> after this was first done in Alaska, and then in New Zealand so the
> people involved had experience with how to look after the
> birds. This amount of new information learnt could not have been
> achieved in any other way.
>
> 2. Satellite Tracking of Little Curlews. Similar to the above, but
> the satellite transmitters were attached by harness. Very little
> information was previously learnt about this species by band and flag
> sightings (mainly local movements) because they are not monitored on
> the rest of their migration cycle. So it was not well known where
> they stopped over, where they bred, etc. This information was
> disseminated very soon after the satellite data was processed every
> few days, and it was a major part of BirdLife Australia's event on
> increasing the awareness of shorebirds in April this year.
>
> 3. Geolocators. This is fascinating. A small one gram device is
> attached to a large leg flag. It records the location of the bird at
> defined periods for as long as the battery lasts. The difference
> from the transmitters is that you must recatch the bird to retrieve
> the geolocator to analyse the data. So this has been used on birds
> that have a high site fidelity such as Ruddy Turnstone, Greater Sand
> Plover and to a lesser extent Red Knot and Great Knot. The results
> are amazing and show the migration paths and breeding areas. Some
> birds have had a second geolocator attached after the first has been
> retrieved, and this allows two years of data to be compared for the
> same individual. Do they use the same migration path? Do they use
> the same stopover site to refuel? etc, etc.
>
> 4. Colour Bands. I admit that I had doubts about the usefulness of
> this technique. As part of the Global Flyway Network project,
> Bar-tailed Godwits, Great Knots and Red Knots were banded with four
> colour bands (two each leg), one yellow leg flag (YLF) and the metal
> band. We had been using plain YLFs, and then yellow engraved leg
> flags (ELFs) and I thought that this was enough to read the flags to
> get the information they wanted. Then as part of the expedition we
> spent a day searching for and recording the ELFs and colour bands in
> Roebuck Bay. The colour bands are much much easier to read. You can
> see them from any angle. You can see then through the legs of other
> birds. You can see them from further away. ELFs must be birds in
> the open and the flag needs to be side on and you need to be
> relatively close to the bird. Three or more people through the GFN
> then spend six to eight weeks each year on the feeding sites at the
> Yellow Sea monitoring the birds passing through. This gives enormous
> information about how and where these birds feed. It shows that you
> can't just protect one important area. Birds move between them, and
> so you need to protect them all. It gives information on
> mortality. It gives information on population sizes. It shows local
> movement within Australia, giving information about how some sites
> interconnect.
>
> This combination of six items on a bird is the most that I am aware
> of. As far as I am aware the most that are used on the smaller
> waders (including Curlew Sandpipers) are two legs flags and a metal
> band. So when I hear hearsay reports of them having seven items, I
> want to see the evidence. Date, place, colours and preferably a
> photo. But each time this claim is made, no evidence is produced. So
> sorry. I don't believe it.
>
> Without this specific data on the movement of individual birds,
> governments won't listen. This data from leg flags and colour bands
> puts more pressure on the governments in the flyway to uphold their
> obligations under the various migratory bird agreements.
>
> 5. Cannon Netting. The teams and the procedures are very experienced
> and detailed now. Yes, unfortunately there are still a few birds
> injured at the time of firing. And this hurts the members of the
> team. These casualties are reported on the catch summary
> sheets. The birds are frozen, and sent to the WA Museum. They can't
> hide the casualties. There are too many volunteers. I understand
> that the 'acceptable' casualty rate is 1%. Maybe early on this
> happened. But casualties are uncommon and we usually achieve 0.2 to
> 0.3% over the course of a three week expedition (about 4,000
> birds). With the new small mesh nets, the birds are very quickly
> removed from the nets and put in keeping cages covered by shade
> cloth. Under the hot conditions at Broome, we need to process and
> release the birds within about three hours of the catch. This is
> always achieved. Why are the birds caught? Our first goal each year
> is to catch enough of 10 key species to be able to estimate the
> breeding success (by determining the percentage of juveniles in the
> population). This data is important in monitoring rises and
> especially falls in the populations. There is a fairly high
> recapture rate. These birds give information about the age
> distribution of the population and allow better estimations of the
> total population. They give information about the movement of the
> birds. For some species, it shows that they are quite highly site specific.
>
> 6. Blood Samples. I still have some reservations about this. Some
> birds do struggle when they are released, and do need to be kept
> longer to recover. The blood samples are taken by AQIS for
> monitoring avian diseases in Australia. Yes, cloacal swipes are also
> taken. During the hysteria of the period when bird flu was an issue,
> these samples showed that this was not an issue for Australia. There
> are a few casualties of birds that have been bled. Even though this
> is not directly due to the normal cannon netting process, they are
> included as casualties in the catch report. The government would
> want some sort of a measure anyway on avian diseases, so it is better
> that the testing is done this way, than through other more drastic
> methods one could think of. Only a small percentage of the catch is
> sampled, and samples are taken on only a few of the catches in
> Broome. Blood sampling in the past has also been used for DNA
> analysis, sex determination and other purposes.
>
> 7. Isotopic analysis of Feathers. This is fascinating. If you know
> when during the migration cycle that a bird grows a particular
> feather (say a secondary covert), then by sampling that feather you
> can determine to a large extent where the bird was at that
> time. This adds to the information from other sources of how birds
> move and where they stopover.
>
> 8. Declines in Populations. It is claimed that the declines are due
> to cannon netting. But this is demonstrably untrue. The age
> analysis of the birds caught show this. The Shorebirds 2020 surveys
> at sites where there is no cannon netting show this, and the number
> of flagged birds in these areas are very low. The birds caught show
> a high site fidelity. But the people making the claims do not read
> the papers, or the survey analysis. I guess the less you know, then
> the more things that you can imagine might happen, even if they have
> already been proven to be untrue.
>
> 9. Raptors. It is true that some birds in the past have been caught
> by raptors as they are released. But the procedures have been
> changed and there were none on last year's expedition. There are
> lookouts posted for raptors. Birds are released in groups rather
> than individually if there is any risk of raptors being around. It
> is everyone's responsibility to lookout for raptors. I don't believe
> that this is an issue any more.
>
>
> Where do I learn about these things? By being a participant in the
> expeditions. By being a member of the AWSG. It is sent by
> email. It is published in Stilt and Tattler (published by the
> AWSG). It is published in international journals. It is on the AWSG
> web site. It is disseminated at shorebird conferences. Some of it
> is communicated on the GFN web site. This information and much more
> is available through cannon netting, and it does further the
> conservation of these species.
>
> There are vacancies for next year's expedition. You do not need to
> be a member of the AWSG. It is not a holiday! There are early
> starts, heat, humidity, lots of other tasks. But there is some time
> for general birding. We look for a team of 23 to 25 people so we can
> safely catch 250 to 300 birds in a catch. If we catch less then we
> fully process each bird (band, flag, age, moult, weight, wing length,
> etc). If we catch more then we reduce the amount of processing so
> that the birds are released well before the three hour limit (at
> least band, flag, age). There are tasks for people of all levels of
> experience and fitness.
>
> The people involved in cannon netting care more about these birds
> than anyone, and do everything they can to promote the conservation
> of these species. They put their time into it. It is grossly unfair
> for them to be criticised.
>
>
> _________________________________________________________________
> Frank O'Connor Birding WA
> http://birdingwa.iinet.net.au
> Phone : (08) 9386 5694 Email :
>
>
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