Well said, Frank.
Carl Clifford
> On 21 Oct 2014, at 23:42, Frank O'Connor <> wrote:
>
>
> 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 :
>
> <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>
|
