BirdingNZ.net

Kia ora
On the 5th & 6th of October, Birds New Zealand had our annual bird survey of Motutapu Island ib the Hauraki Gulf. It was a fabulous weekend with good numbers of Pateke, Saddleback & Kakariki seen in addition to some Whitehead & Shore Plover.
Of concern were a number of Mallard Duck x Pateke hybrids that were seen on the island. This was very disappointing to see & especially after the island had been made predator free & this combined with all the restoration work that has resulted in a growing population of Pateke on the island. Our count areas only included two small ponds, but at one of these (the pumphouse dam) we counted at least three Mallard x Pateke hybrids & these were associating with one drake Mallard & one hen Mallard x Grey Duck hybrid.
Attached are some photos taken by Noel Ward of these hybrids. These birds were larger than typical Pateke, had a different head & bill profile & lacked the white eye ring. The legs also appeared to be slightly orange compared to a typical Pateke. These hybrid Pateke were observed to associate mainly with the Mallards.
Unfortunately, it looks like Mallard Ducks are as much of threat to the endemic Pateke as they are to the native Grey Duck (Parera). My thoughts are that Mallards should be considered an invasive pest, they are a threat to biodiversity & in local areas (inhabited by Pateke & known populations of pure Grey Ducks) they should be controlled whenever possible. I have suggested to the Department of Conservation (DOC) that Mallards & Mallard hybrids be culled on Motutapu Island to ensure that the Pateke population can continue to thrive unmolested.
Cheers
Ian McLean

Attached are a few additional photos for your reference.
Thanks to Noel Ward for the photos.
Cheers

The hybrids actually increase biodiversity because we have two hybrid forms as well as the pure grey ducks and pateke. Mallards and grey ducks have been copulating and producing fertile hybrids for a long time without extinction of the non-hybrid populations and the same might apply to the pateke. I would argue that we need evidence of the likelihood that pateke hybridising with mallards would reduce the pure pateke population to an unsustainable level before culling. I like mallards and their readiness to hybridise with other species, seeing it as increasing the vigour of our waterfowl populations. Rather than an immediate cull, shouldn't we be gathering data on the effects of hybridisation on the pateke population ?

Thank to stupid importor Cecil Whitney for imported wild Mallard ducks to New Zealand 100 years ago.

Read this
https://www.notornis.osnz.org.nz/system ... 202010.pdf


viewtopic.php?f=9&t=7964


We would had have eradicated all of Mallard ducks out of New Zealand before 1940s, when numbers are smaller.

Cecil Whitney would been arrested and be jailed for imported Mallard ducks into New Zealand.

If we want to save our pure native waterfowls as Grey ducks and pateke, We must ERADICATE all of wild Mallard ducks and hybrid ducks.

Or else we will have NO pure patekes and pure Grey ducks and pure native waterfowls.

Hello Jim
Unfortunately Mallard Ducks have exactly the opposite affect as to what you describe. They are an absolute biodiversity disaster for New Zealand & south west Pacific in general. They are the main reason why the native Grey Duck is nationally critical & on the verge of extinction in this country.
Since their most determined introduction into New Zealand (30,000 birds released) for the benefit of duck hunters we are left with a mainly motley collection of hybrids ducks consisting of Mallards mixed with Grey Duck, now Pateke & the numerous farmyard domestic ducks that New Zealanders have dumped around the countryside. In the Mallard we have also exported a biodiversity disaster, with hybridization eliminating Grey Ducks (also called Pacific Black Ducks) from Lord Howe Island & badly affecting duck populations on New Caledonia where 50% of the Pacific Black Duck population are now Mallard hybrids.
Mallard Ducks are probably the most sexually aggressive waterfowl in the world & have been known to cross breed with 63 other species. They are also the gang rapists of the duck world & I have attached a few video links for your reference.

https://www.youtube.com/watch?v=rrxBEfP0Af4

https://www.youtube.com/watch?v=w1hy22uKMqo

Please be aware that these are unpleasant to watch !
Cheers
Ian

See this photo of future New Zealand hybrid ducks...



The best option is to ERADICATE ALL wild Mallard ducks and hybrid Mallard X Grey ducks & Mallard X Patekes only out of New Zealand.

We have seven native ducks...NZ Shelduck, Grey ducks, Grey teals, Patekes, Australasian shovelors, Blue ducks, Scaup, along with Cape Barren geese, Black swans and our domestic Mallard ducks and Domestic Greylag geese and domestic Swan geese and Muscovy ducks.

But let DOMESTIC Mallard ducks & Muscovy ducks stay in New Zealand, to feed us humans.
Domestic Mallard ducks cannot fly and not able to hybridize with our native ducks.

I think the chances of eradicating wild mallards & cross breeds has long passed.
The best that can be hoped for is likely limited control around Pateke while numbers build.

I think the issue needs to also be looked at in perspective - apart from maybe Grey Ducks the risk to other NZ duck species is mainly from predation & habitat loss - these issues are a far greater threat I suspect (at the moment anyway) than hybridisation.
I suspect hybridisation only becomes an issue when numbers reach very low levels - and mates of the same species become few & far between (e.g. Forbes Parakeet, O/F Parakeet).

Given the original population in-balance between Grey & Mallards - aren't NZ hybrids more likely to be Grey Mallards - rather than Mallard Greys...

Cheers
Jim

Jim_j I agree that the eradicated Mallards & hybrids is not possible (sorry Clinton9) but we should keep them in check. Whether you want to call the hybrids Grey-Mallards or Mallard-Greys does not matter it is the Mallards that are the problem. Drake Mallards will try to jump on any type of other waterfowl they can & they have a proven record of doing this where ever they are introduced around the world.
When talking to many birders around New Zealand about Grey Ducks the disappointing things that you quickly become very familiar with are: the rolling of eyes, the almost blaming of the Grey Duck for the problem & the general I don't give a dam attitude !

Here is hard evidences of hybrids between Mallard and goose & shoveler and Ruddy shelduck.



It is useless turn our backs and let nature take course, pure Grey ducks and pure Patekes will become extinct, and we will have new hybrid ducks.

Eradication do not start with just shooting all birds on sight, firstly Mallard ducks will have protection removed and their statement move to unprotected, reach same statement as for Canada geese, and the duckshooters will be trained to shoot Mallard & hybrid ducks only and not pure Grey ducks, while Grey ducks will receive full protection and have same statement as for Patekes & Blue ducks, then Grey ducks no longer in list of Game birds anymore.

Then it will take next several years to get rid NZ of Mallard & hybrid ducks via eradicating.

Today:
Mallard, hybrid & Grey ducks on list of game birds, protected, but hunted during duckshooting season.

Future:
Grey ducks full protected, endangered and no longer on list of game birds. NO shooting anymore.
Mallard ducks & hybrid ducks, same statements as Canada geese, no longer have protection anymore.

Once Mallard ducks & hybrid ducks had been eradicated, the Grey ducks will increase their numbers and replace Mallard ducks.

Here is evidence of hybridizing in Thames.