By Annie Hill
The original article in Russell Lights | Ngā Mārama o Kororāreka April edition 2025

Did you think that the rarest duck in New Zealand is the whio blue duck’?  It is, in fact the pāteke brown teal, which you possibly know nothing about. This enchanting little duck is everything a duck should be, small and chubby, ridiculously buoyant, gregarious (out of the breeding season) and resolutely monogamous. Little brown ducks, with conspicuous white eye rings, they’re unmistakeable.

The male is slightly larger and heavier: 48 cm/650-900 g as compared to 45 cm/ 550-800 g.    Their brown wings look short, and the speculum on the secondary feathers is green (and, unlike what fashion designers and paint manufacturers would have you believe, teal green is a dark, iridescent shade, nowhere near aqua!).  In breeding plumage the males usually have a green sheen on the head and a narrow white ‘collar’, a dark chestnut chest and a whitish patch at the tail base. Their calls are soft trills or piping, given in alarm and or defence. The females and juveniles are a dark, mottled brown; she has a rasping growl and a high-pitched and rapid quack.

They eat a huge variety of terrestrial, freshwater and marine invertebrates, fungi, seeds of sedges, gastropods and bivalves and various freshwater vegetation.

Nocturnal, they spend a lot of time ashore feeding in woodland and paddocks and sieving endlessly in muddy pools. This made them very successful in a predator-free world: now the millions that once roamed happily all over the motu are reduced to at best, 3,000 birds.    These manage to hang on in the wild in Northland (Yes! Here!) and Great Barrier Island, but have otherwise been wiped out. PFR trappers report seeing increasing numbers around the peninsula, now that predators are being so effectively eradicated.

For such small birds, they need a lot of space. In captive breeding programmes they’re fiercely territorial and only on ponds of at least 2,000 sq m, will a pair tolerate other species of waterfowl. Astonishingly, not only will the couple kill all other pāteke, they will then kill all other species of duck that dare to invade their territory. They’ve even been known to assault the equally territorial Paradise Shelduck and Black Swans, both of which are considerably larger than pāteke.

They usually nest in July-September but breed in most months except late autumn.  Typically nests are well hidden in dry locations, deep within clumps of rush, grass or fern.  The females lay huge eggs: each about 10-11% of her body weight, generally one a day for 4 to 6 days, although clutches as large as 13 have been found.   Incubated solely by the female for about a month, once the ducklings have hatched, both parents are excellent parents for the 50-55 days they take to fledge, with the father actively tending to and teaching the ducklings.   However, once fully fledged, they’re forcefully evicted from the breeding territory.  The pair usually then raises another clutch.

When the first Europeans arrived in Aotearoa New Zealand, the endemic brown teal was found in  every swamp and wetland and many riverine systems, in very large numbers in the North and South Islands, Stewart Island and on the Chatham Islands; their numbers were probably well in excess of any other duck.

Pāteke brown teal are subject to the usual litany of threats, but an extra pressure comes from the fact that they like places where we like to build houses and to farm: 90% of the wetlands which provided food and nesting sites have now been drained.   If we see some common-sense planning decisions related to the climate crisis, more of this land will be left alone and pāteke might make a comeback.    They were always hunted in large numbers, but until the advent of guns this probably had little affect on their numbers.  By 1921 there was suficient concern that they were protected, but for many years this was honoured more in the breach; some still get shot ‛by mistake’, even now.    However, all these pressures added together, have done less damage to these little ducks than introduced predators, particularly feral cats, rats and mustelids.  Pāteke are extremely vulnerable to cats, due to their habit of pottering around at night, feeding far from the water, and in Northland, domestic dogs are known to have killed considerable numbers of brown teal at their flock sites.

However, with the successful release of birds from the captive breeding programme, there are ‛sustainable’ (ie with extensive predator control) populations in several places such as Milford Sound and some offshore islands, including Moturua and Urupukapuka, so there are now a few more places where pāteke can live their life in peace.

When teal aren’t murdering one another, ie out of the breeding season, they’re extremely gregarious and form large flocks. The evicted fledglings are the first to flock, followed by the adults whose territories have dried out. When all the adults have moulted and can fly once more they make their way to their favourite flock site. Historically this would have been on a large pond, lagoon or lake, not too far from the birds’ breeding territory. Today the few flock sites which remain are in estuarine habitat, at the confluence of tidal creeks and the sea. This is where pair bonds are re-established and new pairs created. Access to the annual flock site seems to be a critical part of successful pairings and the loss of a site could well threaten the very survival of wild brown teal. These roost sites are traditional and when they’ve been modified, artificially or otherwise, there’ll be a noticeable decline in bird numbers. Pāteke do not adapt readily to change.    

We, who live on the Peninsula, are very privileged to have these delightful birds living near us. Please keep your dogs and cats in at night!