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It
will be nice to have some direct information as to the number of and timing of
release of these birds. Would make an interesting case study. Given the strength
of Mark's conviction to his memory I have no reason to doubt that someone could
have released some individuals of this species. Was there any other person who
was present at the time of the release of these birds to confirm the story or
just the person who allegedly did it? For Mark's conclusion to be true, I
suggest this release must have happened many times since then and in recent
years.
If as
Mark writes the birds were released in the late 1970’s,
early 80’s (let's go with your memory and say about 30 years
ago) and I do gather that these birds on the FSW have bred then
what happened to the chicks produced there? These chicks are not released
aviary bred birds, they are wild bred birds. Even without breeding, if
these releases occurred about 30 years ago, it is not likely to be correct that
all The birds on the Fyshwick Sewage Ponds are released
aviary bred birds. What is the chance that all the
birds present in recent years (say about the last decade) are all 20 to 35
years old?
I
unashamedly take "The birds on the Fyshwick Sewage Ponds"
in the context of the quote, as referring directly to
the specific individuals (as not just any member of the species) over all
the records of the last many years. I don't accept that those birds could have
lived that long and had populations be so variable without breeding and without
natural migration in and out of the area. The birds have often been missing over
the last several years and then returned some months later in different
numbers and sex ratios. The absences cannot all be explained by being hard to
find.
It is
hard to comprehend that if several people have known of this for years, that it
has never been published. In Steve Wilson's book for one. If Chris knew this and
is the author of the duck section in the COG ABR, not adding that is a huge
omission. I now notice that the COG Atlas (page 191) mentions only two records
in the whole three year Atlas period (1986 to 1989), one in September 1986 at
Lanyon and only one bird probably recorded twice: in March and April 1988 at
FSP. I also note that the COG Atlas does not include the species in
Appendix 2 "escapees and releases". Why not? My recollection of the process of
writing and editing the Atlas text is that many members (such as myself) had a
lot of input into the text of this book. Chris Davey is acknowledged as on the
editorial subcommittee (page 2). If he knew that the (one only) bird recorded
twice at FSP was a released pet, why was the species not included in Appendix
2? That would be another huge omission. For all the effort devoted
into the Atlas project, I consider it untenable that the birds released about 30
years ago, transmogrified into only one bird for two months at that site over
that whole three year period and then into the higher numbers of about 10 in
recent years and they are all the same occasional one or somehow several birds.
Sorry the idea does not stack up.
Sure,
someone may have released some individuals of this species about 30 years ago
but unless this has happened many times since over a period of decades, the
available records suggest those released birds mostly died out or left and
the recent variable population is more likely to be natural recolonisation. And
why wouldn't it be?
Philip
Thanks for all the comments from people concerning the
Blue-bills at the FSW. I gather that Peter Fullagar will be meeting with the
person who released them in the near future so hopefully we will have a date. I
have a vague recollection that the birds were released in the late 1970’s, early
80’s but could be wrong.
To answer the question posed by Philip as to why this has
only been brought up over the last three weeks, I, as well as Peter and Chris
and several former staff members from CSIRO “Wildlife”, have known about this
for years, it is only when I went down to check that they were still there three
weeks ago and found that they were “missing” that I brought the matter up.
Anyone who knows me knows that I am not in the habit of making things up. We
also know that there are dodgy breeding records in the local area but I do
gather that these birds on the FSW have bred.
Mark
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