Birds that have not reached NZ, but should

[Clinton9]

During autumntime migration these silvereyes were very fat and being blewn to NZ over 100 years ago, had leaded to today's silvereyes here. The bodyfats had kept sivereyes stayed alive during 2,000 k/m flight.
During autumn the silvereyes migrated from Tasmania, to mainland Australia for winter.

[Davidthomas]

I realise this, but silver eyes weigh 15 grams max. compared to that of 400+ for most ducks Realistically they have far higher chance of surviving long distances than a bird which can lose 10% of its body weight in a few hours

[Byrd]

Here is my take on the list in the original post. A lot of it is just my personal opinion obviously so feel free to disagree, but most of these I have seen many times in Australia and elsewhere. As has already been said though, the title would be better as birds that could arrive because there’s really no good reason why any of them should.

-Black-faced cormorant: certainly one I would expect at some point, just because it is the only Australian cormorant not here yet and it is found plentifully round the Tasmanian coasts. Not sure about its dispersal powers though, so my certainty could be completely unfounded.
-Magpie goose: probably not. Its a big bird and a powerful flier (e.g. back and forth between Australia and New Guinea, albeit that is a much shorter distance than Australia and NZ), however it is also largely a bird of the northern tropics so it would have to get wildly lost to end up here. We are simply in the wrong direction.
-Wandering whistling-duck: I don’t see why not (as in I can’t think of any good argument against it arriving here at some point....)
-Freckled duck: a very good candidate in my opinion because it is strongly nomadic, like the pink-eared duck of which there is but one NZ record (from 1990), and it lives in the nearest part of Australia to us.
-Blue-billed duck: another good candidate, as I mentioned earlier in the thread.
-Musk duck: same as above (plus NZ had its own musk duck which was plainly derived from Australian arrivals). I would love to see a musk duck in NZ!!
-Black bittern: good pick.
-Striated heron: good pick. They are widespread and so must be good dispersers. (Wasn’t there an unconfirmed sighting a while back?)
-Jabiru stork: unlikely in my opinion. It is largely a northern bird. However storks are great travellers and black-necked storks are rather nomadic at times.
-Wood sandpiper: quite possible. Most Australian ones are in the north and northwest but they also appear elsewhere in the country. I guess any migratory wader could appear in NZ. There was a stilt sandpiper a couple of years ago which was the first NZ record, and which I would consider more unlikely than a wood sandpiper.
-Australian pratincole: these are really cool birds, but probably unlikely. They live in (more or less) central areas, migrate south to breed and north (including into southeast Asia) for winter. So the only real chance of one in NZ is probably if one got lost when heading to the south of Australia to breed, and that’s probably an unlikely overshoot. Happy to be proved wrong if one turns up here though!!
-Bush stone-curlew: unlikely. They are good fliers but are now largely of a tropical north distribution.
-Beach stone-curlew: very unlikely in my opinion, but this is my absolute favourite bird on the list. They are brilliant birds.
-Comb-crested Jacana: sort of nomadic in response to drought etc but also largely a tropical species. Not at all likely for me.
-Banded Lapwing (Not banded dotterel): don’t see why not.
-Little ringed plover: a rare visitor to northern Australia so I’m not sure why you think it “should” get here from there, but see what I said for wood sandpiper and I suppose it holds just as true.
-Black tern: a VERY rare vagrant to Australia; not sure why you’ve included it in your list.
-Black-naped tern: don’t see why not. It’s a tropical bird but tropical seabirds are more likely to end up random places than tropical land/freshwater birds. Good luck finding one if it does turn up though!
-Lesser crested tern: as above.
-Osprey: this one is a good one because it is one of the most widespread birds in the world (depending on how one splits it of course) and I’ve always wondered about its absence. There was a record one or two years ago (from a fishing boat off the Chathams?) but I don’t know if it was accepted or not.
-Other birds of prey: most open country birds of prey could reasonably be expected I guess, particularly ones that have a wandering or nomadic nature, but considering how few vagrants there are on record from NZ (basically lots of nankeen kestrels, a few black kites, one supposed black falcon, several older sight records of white-breasted sea eagles) don’t hold your breath for any of them! Peregrine is one in particular that might reasonably be expected given (like osprey and barn owl) its world-wide distribution.
-Black-eared cuckoo: a good choice; it’s migratory to the south so could easily overshoot.
-Little bronze-cuckoo: a tropical species; I can’t see it getting here at all.
-Eastern koel: already recorded. I can’t remember the year (maybe ten years ago?); the specimen is in the Canterbury Museum.
-Powerful owl: pretty unlikely, although they do occur in some pretty urbanised environments (e.g. the Sydney Botanic Gardens!). They could make a real mess of a kokako so best if they stay where they are!
-Barking owl: found in open woodland, forest edge, etc, so could conceivably end up here. Not as far-ranging as barn owls in habit though so far less likely, and there are few enough barn owl records from NZ!
-Sooty owl: really unlikely that a rainforest owl would end up as a vagrant.
-Tawny frogmouth: this just seems extremely unlikely. Frogmouths can fly obviously, and apparently quite fast too, but I seriously doubt they have the capabilities of crossing an entire ocean. I’d rate frogmouth as a zero chance.
-White-throated nightjar: I guess so...I’ll be cautious with this one. They are good fliers, they do migrate seasonally (including over oceans and straits), and they are common in Australia.
-Australian owlet-nightjar: perhaps. I don’t know how good they are at flying long distances. NZ did have its own species derived from an early colonisation from Australia. I doubt anyone would know if one did turn up though, they aren’t exactly the most obvious of birds!
-Azure kingfisher: I suppose, they range pretty far south, but they are quite a little bird. Would they make it? I can’t see it myself.
-Forest kingfisher: collared kingfisher would seem a more logical choice for your list than forest kingfisher....
-Fairy-wrens: yeah, no. The Australian wrens are poor fliers. It would be like suggesting that riflemen could end up in Australia.
-White-browed scrubwren: I’ve never seen scrubwrens doing a lot of flying, they tend to skulk. But I suppose with the right wind they might make it. But you couldn’t use the waxeye argument to say they could be expected in NZ. I would frankly be very surprised if one was ever seen in NZ.
-Yellow-rumped thornbill: any reason for picking yellow-rumped over any of the other thornbills? Probably more likely than scrubwrens due to their more active arboreal lifestyle, but far less likely than waxeyes. Again, I’d be very surprised to see one in NZ.
-Honeyeaters: a perhaps surprising lack of records of any species from NZ apart for the red wattlebirds. Some of them are good strong fliers, they have good dispersal powers (lots of island species and populations). I wouldn’t be surprised at all to hear of a friarbird or something like that in NZ.

[Clinton9]

Few birds managed to arrive from USA:

Frankin's gull arrived 2 times in NZ.
Hudsonian godwits, with one bird in Miranda.

One moulting adult Frankin's gull was photoed in NZ and in front covert of "Southern Birds" few years ago.

One Hudsonian godwit was been seen in beach in Miranda, throught I am not sure whether it overwintered in Miranda or migrated with Bar-tailed godwits back to breeding areas on northern North America.

In 1980s few Northern shoveler came to NZ, and in 1990s a male Pintail duck came to NZ & joined mallard ducks.

Seaval years ago I had seen a adult Asian Black-tailed godwit in eclipse plumage on mudflat in Firth of Thames, 20 yards from Bird Hide whose I sat & birdwatching the godwits.

I had seen a pair of adult cattle egrets flying over mudflat in Firth of Thames in November of mid 2000s. These cattle egrets were in breeding plumages. I reported to David Lawie about egrets.

[SomesBirder]

Franklin's gull have arrived to NZ three times. One reached the Kermadecs in 1988. The other two were in the Northern NI.

[Clinton9]

Franklin's gulls were alive when they arrived in NZ. These birds arrived in Nth Island, were adult birds and were alive and able to fly.

Were the Franklin's gull alive when seen in Kermadecs in 1988 ???

I don't understand why these gulls came to New Zealand, since winds tends to go eastward and there are no ships in mid sea.

Nothing told these gulls to fly to NZ.

[Byrd]

Franklin's gulls were alive when they arrived in NZ. These birds arrived in Nth Island, were adult birds and were alive and able to fly.

Were the Franklin's gull alive when seen in Kermadecs in 1988 ???

the Franklin's gull on Raoul island was alive when it was photographed there in 1988

[Clinton9]

And now three gulls are in USA, look after & feeding their chicks, and we don't have Franklin's gulls living in New Zealand now.

I do not know whether birds tell other birds or not about coming to NZ, Franklin's gulls properly won't say "New Zealand is a safe country, with much fewer predators" Most Franklin's gulls had no idea about NZ.
Our Red-billed gulls & Kelp gulls did not talk so much as their major day activilies are spent on looking for foods to eat.
Birds do not tell other each same way as humen do.

But birds can learn.

[SomesBirder]

What really confuses me is that there is a very large number of Franklin's gull records from Australia, but only three in NZ.

[Clinton9]

Same to me I were confused about lots of Franklin's gulls in Australia and 3 birds in NZ.