Confiding nesting owl

In the second edition of M.F. Soper's New Zealand Birds (1976), the author writes more about the little owl than he does about any other introduced species, which I presume means that it was the only introduced species that he didn't dislike. Included in the text about the species is the following:

When first hatched the chicks are covered with a white down. For the first week or ten days the female is very reluctant to leave them and will allow an observer who wishes to find out how brooding is progressing to slip his hand underneath her and lift her off the nest. The owl does not like the treatment and will hiss and clatter her beak, but if one is gentle and unhurried she will not attack or fly away.

It would be interesting if other birders could try this so that whether or not most specimens are that calm could be revealed.

Another problem coloniser

The barn owl is a bird species that apparently colonised New Zealand some time around 2007, when a pair bred on private land in Northland and produced one chick; the chick survived and nearly fledged until it was found injured and subsequently taken into captivity, where it remains. The original pair of barn owls have allegedly produced other offspring since and formed a small population, but due to the fact that they are on private land and the land owner wants all but a few of the people who want to see them to keep their distance, this is difficult to determine.

Obviously, birds of prey are probably the most concerning birds when it comes to their ecological impact once they colonise a place where they did not previously exist.

This varies between species, however; for example, if the nankeen kestrel, a rare vagrant to NZ, became a coloniser, as has been long-anticipated, it is unlikely that it would have a significant impact on any of NZ's species that could serve as its prey. It shares habits with the harrier and NZ falcon; having a preference for open country like the harrier, and having a similar physiology to the NZ falcon. Therefore, it's nothing new to NZ's prey species.

The barn owl, however, is very different from the nankeen kestrel, and I have found enough to suggest that its presence here is something to be concerned about.

Denny's 'A Photographic Guide to the Birds of Hawaii', published in 2010, reads, 'The Barn Owl can be found throughout Hawaii. Sugar planters introduced it in the late 1950s in an effort to control rats in the fields. Rodents do make up a large part of its diet; but the Barn Owl also preys on birds and has been responsible for nesting failures of seabirds at Kilauea Point National Wildlife Refuge'.

So significant is this impact on Hawaii's native species that their eradication from the state is planned.

NZ's barn owls are likely to have a similar impact, should they spread, and there are going to be plenty of easy targets in store if they do. In my opinion, they need to be watched closely... Or would need to be, if they weren't on private land...

If NZ's barn owls had been introduced, I can guarantee that there would have been efforts to 'nip the bud' immediately, but that's just the omnipresent native-vs.-introduced double standard at work...

If NZ's barn owls do spread and become an ecological pest, it wouldn't be the first time a species of large owl became a problem after reaching a foreign land under its own steam. In the National Geographic Field Guide to the Birds of North America (2011), a part about Bermuda reads, 'Surprising northern species that have occurred include Northern Hawk Owl, Snowy Owl, Bohemian Waxwing, White-winged Crossbill, and Pine Grosbeak. The single Snowy Owl (1987) took to predating the endangered Bermuda Petrels and had to be collected. (Sometimes conservationists have to make hard choices!)'.

I doubt that this has happened before

When driving around the pond at Queen Elizabeth Park in Masterton today, I saw what I thought was a paradise shelduck pair standing on its edge, and decided to take a closer look.

As for what they actually were?

Well...

An undesirable coloniser?

The Australian white ibis is a rare vagrant to New Zealand, with no confirmed reports since 1989. This, however, does not change the fact that, under the right conditions, a flock of them could eventually reach New Zealand and breed here.

The sacred ibis, a close relative of the white ibis that was formerly treated as being the same species (if I remember correctly), has gone feral in parts of Europe, most notably in France, and unlike most introduced bird species, it has certainly earned its title of being a major ecological pest.

This is because it predates on tern eggs and chicks, and terns being much smaller than ibises, they cannot effectively defend their nesting sites. A document that I no longer have access to described ibises being observed in the process of destroying every egg and chick at a single colony; if I remember correctly, the number of ibises involved was very small, and they finished off the eggs and chicks of the colony in a matter of hours.

That's just as bad as the damage dealt by mustelids and cats to tern colonies here, and similarly, the ibises are being culled there (in fact, I haven't found anything regarding whether or not any currently remain there).

New Zealand has two highly-threatened endemic terns; the black-fronted tern, and the NZ subspecies of the fairy tern.

I don't know whether or not the Australian white ibis predates on tern eggs and chicks, but the fact that it's very closely related to the sacred ibis alone is enough for me to assume that it does.

Obviously, what I'm saying is that Australian white ibises colonising New Zealand may be exactly what NZ's endemic terns don't need, especially when the threat presented by cats, mustelids, rats, etc. is still far from gone.

No, I am not saying that any Australian white ibises that reach NZ should be shot on sight, as in what happens to Canada geese and house crows in Australia.

What I am saying, though, is that this is a species that has the potential to have a major negative impact on at least two of NZ's endemic birds, and that this should be kept in mind.

It's a perfect example of how just because a new coloniser in New Zealand is good news for birders, it isn't necessarily good news for other birds.

The end of the crimson rosellas

Back when I started birding and saw the crimson rosella in Robertson & Heather's field guide, it was one of the birds that I was most looking forward to finding. Imagine my disappointment when I found out that this was no longer possible, as the last of the genuinely wild birds died out before the late 1990s.

There have been two instances of the crimson rosella occurring in the wild in NZ in small numbers. The first of these was in Otago. W. R. B. Oliver's New Zealand Birds, the second edition published in 1955, reads, 'About 1910 a small shipment of Eastern Rosellas, including a few Crimson Rosellas, that had been refused entry into New Zealand by the Customs Department, was released off Otago Heads by the ship which brought them as she was returning to Sydney. The two species crossed and now no pure birds of the crimson rosella remain in the Dunedin area'.

This probably means that all of Dunedin's eastern rosellas are technically hybrids, but because they breed 'true to type', they are considered to be pure eastern rosellas, phenotype-wise. It would be interesting if DNA testing could confirm this, but there's a good chance that any crimson rosella DNA that these birds carry is now dilute to the point of being undetectable.

The second instance of wild crimson rosellas occurring in New Zealand is a better-known population that arose in Wellington in the early 1960s, but was gone before the late 1990s (in the 1999-2004 survey of the bird distribution of New Zealand, only two crimson rosellas were recorded; neither of which were near where the Wellington birds were). Whether they ceased to exist by hybridising with eastern rosellas or simply dying out is difficult to determine.

Eastern rosellas certainly would have existed where crimson rosellas did while the Wellington population still existed, but I have found nothing in regards to whether the two species were seen interacting, or whether any hybrids were seen. Again, DNA testing could help determine whether or not Wellington's eastern rosellas carry crimson rosella blood.

Another possibility is that crimson rosellas ceased to exist in Wellington via being trapped and sold as aviary birds; after all, some Australians consider the crimson rosella to be their most beautiful-looking native parrot.

I would love if a new population could form somewhere as a result of some of them escaping from captivity, but I doubt that any other NZ birders would, and the DoC and/or MPI would probably want them gone ASAP.

The bobwhite quail in New Zealand

The bobwhite quail is similar to the grey partridge in the way that it is a gamebird that was introduced for hunting, but failed to establish. Its history in New Zealand, however, is quite different from that of the grey partridge.

The 2010 OSNZ checklist reads, 'Introduced and liberated throughout the North and South Islands (summer 1899-1900) with a second release on the east coast of the North Island (1902). Persisted in south Auckland until at least 1922 and possibly in the Wairoa area until 1970'. The rather vague description of their liberation doesn't say how many were released; if they had been released in low numbers, then perhaps this played a role in their not becoming established in the wild.

That aside, it seems that the population of bobwhite quails that was considered 'tick-able' is now long gone.

For some reason, in the NZ publication More Outdoor with rifle and shotgun, published in 1980, the following illustration is included, which clearly depicts a covey of bobwhite quails. The picture is unlabelled, however, and from what I can tell, there is no mention of the species in the book. This means that whether the illustration is meant to be of wild birds or domestic stock cannot be determined. Perhaps it was drawn by someone who was commissioned to illustrate quails, which were meant to be California quails, which are mentioned in the book, but was not told exactly which species of quail he was meant to draw.

Fortunately, unlike the grey partridge, bobwhite quails still exist in captivity in New Zealand, and apparently aren't rare. This means that more recent attempts at introducing them into the wild have been possible.

Morris & Ballance's Beautiful Birds of New Zealand, published in 2006, reads, 'A handful of people are now breeding and releasing bobwhite quail onto pasture around Timaru and Ashburton. The birds are reared in moveable coops. When the time comes the coops are moved to the release site and the doors are opened, allowing the birds to leave in their own time. They can continue to return to the coop, entering and leaving through a port in the roof to safely feed out of reach of predators'. Going by the lack of any records of wild birds seen in either area since that time, though, it seems that nothing ever became of this. Nowhere, however, does the text state that those who were breeding and releasing them actually intended for them to become established in the wild there.

Finally, the 2009 edition of Stuart Chambers' Birds of New Zealand Locality Guide states that some bobwhite quails were seen in Dargaville, Northland, in 2006. Perhaps these records refer to a genuine attempt at establishing the species in the wild there.

In my opinion, the bobwhite quail would certainly be a nice addition to the rural areas of NZ, but it seems that it isn't going to become an established species here any time soon.

A complete failure

When the revised version of Robertson & Heather's guide to New Zealand birds was finally released last year, some people disapproved of the fact that it retained the grey partridge in the field guide section, describing it as a 'Rare European Introduction', and including a range map which indicated that it could be found in the southern South Island.

And they had reason to, due to the fact that it has now been a great many years since a single one of them has graced New Zealand's countryside.

The introduction of the grey partridge in New Zealand, and its failure, is an interesting and unusual event in the history of New Zealand's avifauna that tends to go overlooked.

Included in the 2010 Checklist of the Birds of New Zealand is an account of its history; it was introduced in several places throughout the country in the late 19th and early 20th centuries, and 'Some of these early introductions were briefly successful but all ultimately failed'. The text goes on to say that, beginning in 1961, there were a number of serious attempts to establish the species in the southern half of the South Island, and, 'Between 1964 and 1970, 11,000 grey partridges were released in North Canterbury alone'.

The handbook section of Robertson & Heather's revised guide reads, '... a few birds persisted in Southland until at least the 1980s'. Even this, however, is a baseless statement; in the 1969-1976 survey of the distribution of birds in New Zealand, there were only three grey partridge records; one in the North Island, and two in the South, with the last of these occurring in 1975. The North Island record during this time is unusual, given that there were no releases of the species there during or shortly before the survey was underway; my guess is that it was either a misidentified juvenile pheasant, an escapee from private hands, or the remnant of an unauthorised attempt at establishing the species in the North Island.

This brings the question of, what caused this species to die out so quickly?

I think that climate can be ruled out as being the primary cause for their failure at establishing. The climate of where they were released in the South Island would not have been much different from the climate of many of the places where they are found in their native range. I believe that, in most cases, it is unlikely for any large number of birds to quickly die out with an unsuitable climate as the primary cause; after all, the myna, a species that is intolerant to cold climates which has shown that it cannot breed south of Whanganui (or Foxton?), persisted in the South Island for at least a decade when it was introduced there in the 1870s.

Predation is an obvious possibility as to why they failed to establish as well. In regards to the predators that it would/could have encountered when it was introduced to New Zealand; cats, dogs, mustelids, falcons, and harriers would have been able to take the species at any stage of life; herons, rats, pukeko, and possibly little owls would have been able to take the eggs and chicks of the species, and mice and hedgehogs would have been able to take the eggs of the species. Weka would have been a threat to the species at all stages of life as well, but from what I can tell, the range of the weka and grey partridge when the more recent attempts at establishment were made would have overlapped either only slightly or not at all. Regardless, that is a considerable number of threats to the species, and yet, wouldn't such animals as foxes and martens, among others, be predators that the grey partridge would have been adapted to avoid in its native land, meaning that the predators in New Zealand wouldn't have been unusual to it? As well as this, the California quail was fairly widespread in parts of where the grey partridge would have been introduced to, meaning that they were able to survive such pressure from predation, despite having similar habits to the grey partridge, so surely the pressure from predation wouldn't have been so extreme as to be the main reason for why the species couldn't establish there?

Finally, what I think may be the most likely reason for their failure at establishing is changes in agricultural practices. In recent years, the grey partridge has sharply declined in parts of its native range due to agricultural practices changing where they live. It's fair to assume that such practices would have effected NZ's grey partridges as well, but I have no information about this at hand.

That's it, really. The grey partridge will probably never be seen in the wild here again, given that the importation of almost all birds into New Zealand is now illegal, and that there are apparently no grey partridges in captivity here. The grey partridge should be remembered as a member of the past of NZ's avifauna, but not its present.