BirdingNZ.net

Posted: **Thu Apr 15, 2021 10:30 am**

This is all good info. Thanks for the further discussion here.

I don't think the period of time is really an issue for either population - Chats or EC - 10 years is a good benchmark, and clearly this has been exceeded in both cases. I think the question really is the level of 'self-sustaining' - are both of these really self-sustaining? Are there regular escapee emus adding to the population? After all these are long-lived birds that would not necessarily need to produce many young to see a slow increase in population size. Are they really producing surviving young without any assistance from humans? I suspect in both locations the answer is yes, but I think this is what the addition to the list hinges on at this point.

I don't see the habitat as a problem - clearly grasslands/mixed shrubland of some description is going to be their preferred habitat, and as such in both cases the populations are found in farm paddocks. As long as those farm paddocks provide free and unrestricted movement then I don't see a problem. After all from what I understand the Chats birds are generally seen in the gorse dominated paddocks at the end of Rapanui Road. Not sure a restricted range should necessarily be an issue, so if the Chats birds are included, the restricted range of the EC birds shouldn't be a problem either?

Let's keep the discussion going. Further info on the level of human assistance would be welcomed.

Many thanks,

Posted: **Fri Apr 16, 2021 9:19 am**

RussCannings wrote:I too hope more robust info can come to light about East Coast emus but it seems well established (to the best of our knowledge) that they are indeed feral (not kept by humans), are free-ranging, and have been for around 30 years. Even if their population is smaller than on the Chathams (not even sure if it is?), should that matter? Troy mentions that they are usually seen in 'paddocks' and so seem 'less wild'. What alternative do they have? They are open-country birds and the only other habitats in that area are dense scrub/forest and riverbed (Where they also occur commonly according to my Gizzy friend).

It may seem like I'm strongly advocating for East Coast emus to be 'tickable' but I want to make it clear that I'm more interested in having a consistent approach to all feral species. What are the rules? Is there a minimum population requirement? Is there a minimum "time in the wild" requirement? What is the tolerance for human impact (Supplemental feeding/introductions etc.)? Who is qualified to investigate these facts and what should they do to propose a new species to the checklist committee?

I like Brent's idea of attributing specific geographic areas for countable feral species. This could evolve over time but would not only help guide 'listers' but also eBird reviewers and atlassing. We're speaking of emus on this thread, but I'm reminded of South Island pheasants, peafowl, and turkey. Are there legitimate populations on the South Island? If so, which ones?

Because many(all?) of these species are sporadically released deliberately or by accident throughout the country, we will never have a perfect solution, but I think we all see the benefits of recognising the real-life, on the ground NZ avifauna, native or not.

Russ

I totally agree with something like that as well...

I do also feel that there should be something similar when regarding first time breeding from vagrant Australian wood duck, stragglers gull billed tern, migrants Glossy Ibis and the like and when does one become an official native breeding species... ( I hate the term "coloniser...." I much prefer yip anything that arrives here unassisted is native but to me the actual term native is, I feel, a better fit/reserved for when they breed here or a term recently self-introduced native)

But when does a pair of vagrant/straggler/migrant birds looses that vagrant status and becomes a native breeding species as I feel it is some what hit and miss.... Lets look at a couple great examples and how it adds to some confusion...

Barn owl
When the very first documented case of breeding was found... Wingspan through various media outlets... Our newest native species, New Zealands newest native species... A Barn owl pair has just been discovered breeding making it our newest native species!!!!

Horay grebe....
A pair found breeding yet nothing in the form of media "Our newest native species" and regarding NZ birds online still vagrant.....

Australian Wood duck
A number of pairs found breeding yet a nothing on media and few here were skeptical of taking it off the vagrant list to start with...

Like the 10 year rule idea with when farm birds can become a tickable species, at what point would you guys agree with when (using the term Native in regards to breeding in NZ) at what point do you take a species off the vagrant (and the like) list and reclassify as a native breeding species.

Posted: **Fri Apr 16, 2021 10:02 am**

Kia ora Fraser

Yes, it would be helpful to have rules on when does a vagrant species that has bred in New Zealand become considered an established breeding species. But there is a specific reason for why the term 'Coloniser' is used in the NZ Threat Classification system. Colonisers are native. However, any native species with a population of fewer than 250 breeding adults is automatically ranked as Nationally Critical. 'Coloniser' is used as a descriptor for the first 50 years or so after breeding is detected, so that new arrivals (that may be super-abundant in Australia) don't get classified as Nationally Critical as soon as they lay an egg in New Zealand, and potentially drain conservation resources (or attention) away from Nationally Critical endemic taxa.

New Zealand bird threat classifications are updated on a 5-year cycle, and it is hoped that the next iteration will be published this year. NZ Birds Online rankings are updated as soon as the new lists are published.

Ngā mihi
Colin

BirdingNZ.net

Emus next on the NZ list?

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Re: Emus next on the NZ list?

Re: Emus next on the NZ list?