Hi all,
|Further to Bills mention of potential negative interactions between the
|introduced Mallard and Pacific Black Ducks. I offer some interesting
|information for the list.
As a Kiwi reading about this situation I find it hard to believe that
nothing was or is being done about this situation. Or is something about
to be done??
Here in New Zealand we supposedly have an estimated population of around
3-5 million mallard, and 1-2 million grey duck. The estimate of
mallard's may in fact be close to that, but the estimate of grey duck
has to be hugely inflated (the estimate methodology does have flaws).
As a birder that does a fair bit of travelling around the country, and
visits a fair few different habitats, I don't often see what I would
consider phenotypic Grey ducks (and when I do they are almost always
accompanied by mallards!). What's more, many of those 'phenotypic' Grey
ducks may well be hybrids due to the fact that often, as mentioned by
Martin, hybrids can exhibit Grey duck features.
Grey ducks are in my mind a species which is in a serious situation
given the current state of affairs here in New Zealand. The problem
here appears to have been exacerbated by NZ's hugely modified landscape
- something that mallards have taken advantage of and Grey duck appear
to have been negatively influenced by. However, mallards have invaded
most habitats, and it is during the 'invasion' stage that Grey duck
appear to be most at risk from hybridisation. Some fantastic work in
restoring native waterways recently in Christchurch, NZ, shows that Grey
duck will return to restored habitats and appear to do well, whilst
Mallards are not so prevalent. However, has the 'genetic' damage
already been done??
I would hope that something to halt the invasion of mallards in
Australia is about to be done......or is it too late?
Regards,
Brent
Brent Stephenson
Eco-Vista: Photography & Research + Wrybill Birding Tours, NZ
email
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