Tasman Every Day

Black-billed gulls (Larus bulleri) have the most amazing white eyes ringed in what look to me like tiny stitches crocheted in scarlet wool. Then there’s the crisp, smooth white of the head and the deep black of its bill… the black-billed gull is a beautiful bird.

Gulls are often thought of as seabirds, but the black-billed gull (Larus bulleri) is more likely to be found around freshwater: rivers, lakes, marshes, pastures. They breed on the gravel beds of braided rivers, which provide them with a clear space to nest on and easy access to a reliable food source. In 2016, a dairy farm in North Canterbury hosted a colony of 300 black-billed gull nests, which fledged 440 chicks. In the Tasman District, black-billed gulls occasionally breed at Farewell Spit and Rototai, but not in large numbers.

Anklets are trending in 2018! Especially among New Zealand’s more threatened bird species. Black-billed gulls (Larus bulleri) have been banded as part of studies trying to determine how many chicks fledge each season, how many survive to breed in subsequent seasons and where they spend their winters. Birds are given two bands, a metal band with a number and a coloured band that indicates what breeding colony the bird was banded at. This gull was being uncooperative, in standing on only one leg. (Yes, we have reported the sighting, even though we have only partial information.)

Update

We had a reply back from the researcher, enough info was visible to ID the bird. It was banded as a chick on the Wairau River in December 2014, so is four years old. Black-billed gulls usually breed for the first time at two years of age, which this one did. It was recorded overwintering in Kaikoura in 2015 and 2016, and at Lake Rotoiti for the last two winters.

If you think this black-billed gull (Larus bulleri) isn’t looking too impressed, you try being the most threatened gull species in the world. The black-billed gull is very similar in looks to the much more common (but also declining) red-billed gulls (Larus novaehollandiae) often found around the coast. The black-billed gull is a more slender bird, with a longer bill. But matters can be confusing, as red-billed gull juveniles have a brown-black bill and legs that turn red as the birds mature. Black-billed gulls do the reverse, going from red bill/legs as juveniles to black as adults. The intense black of this bird’s bill is unique to black-billed gulls; the bills of juvenile red-billed gulls are never this dark and uniform in colour.

On one hand, you have New Zealand’s most common coastal gull, the red-billed gull. On the other hand, you have this guy, the black-billed gull (Larus bulleri), which is not just New Zealand’s most threatened gull species, but the world’s most threatened. Their numbers are still okay, but the rate of decline is a serious worry: The black-billed gull’s stronghold is Southland, and there its populations has declined by 80% in the last thirty years. This bird was photographed at Lake Rotoiti, in Nelson Lakes National Park.

Have you ever fallen into that black hole that is watching owl videos on YouTube? No? Never mind… Following all the little bird introductions of the late 1800s, it was time to bring in the little owl to control them. Between 1906 and 1920, around 200 little owls (Athene noctua) were released by the Otago Acclimatisation Society. More were released in Canterbury, and together, these Otago and Canterbury little owls have spread throughout the eastern parts of the South Island and up into the Tasman District, where they quite like Golden Bay (because who doesn’t?!). The hope was that they would eat all the small introduced birds that had become pests; the major flaw in this cunning plan was that little owls eat mostly moths. Okay, so they weren’t great at their intended purpose, but at least they’re not a threat to native bird species? They do seem to compete for habitat with the native morepork. Adult little owls have spots on their heads, which this one doesn’t, so it is likely a recently fledged bird.

Starlings (Sturnus vulgaris vulgaris) were first released by the Nelson Acclimatisation Society in 1862, and only around a thousand were brought in to the country altogether. They’ve spread just about everywhere, except dense forests and mountains. Their introduction has been a success, from a farming point of view, as they were brought in to control insects pests, especially grass grub (Costelytra zealandica). They compete for nesting sites with native birds that nest in cavities, but that isn’t a significant problem as they simply don’t occur where New Zealand’s cavity-nesting species occur. Except at restoration sites on offshore islands (black robin, some endangered parakeet species). From a nice-bird-to-have-around point of view, they’re kind of noisy and aggressive and their vocal dexterity is not used in a particularly charming way. Not to mention that their nests and offspring make a lot of mess. And noise. The bird in this photo has recently molted, the giveway is the white points on the tips of its feathers. The white-tipped feathers are non-breeding plumage, and as the feathers age, the white tips will wear off, revealing the glossy disco outfit the starling will wear for the breeding season.

The European greenfinch (Chloris chloris) was among the wave of birds introduced to New Zealand in the 1860s. They’re known for their song in some parts of the world and are caught and kept as songbirds. Possibly that’s the reason they were brought to New Zealand, because settlers wanted to hear familiar songbirds. By the turn of the 20th century, their importation was regarded as a serious mistake due to their fondness for seed crops, and in 1903 they were proclaimed “injurious birds” under the Birds Nuisance Act of 1902. The “chloris” of their scientific name means green. I love the vividness of his splashes of colour contrasted with the pale brown of the rest of him.

The male chaffinch (Fringilla coelebs gengleri) sports this lovely silver aviator cap year round, but his colours get really intense in spring. Chaffinches were among the 130 bird species introduced to New Zealand following European settlement, and this seems to have been one of the less harmful introductions. They do some damage to fruits and crops, and it’s not known whether they have any significant impact on native wildlife. I searched Papers Past for references to chaffinch plagues, but came up empty. What I did find was reference to “The Chaffinch Conspiracy”, an Australian criminal case in 1911 in which the director of “The Great Chaffinch Company” had been accused of salting the lease. He had claimed to discover a potentially lucrative gold deposit near another gold mine, one which was genuine. A mining engineer hired to investigate the suspiciously rich find found nothing, which led to the charges against the Chaffinch conspirators, not to mention the stocks of all nearby mines taking a dive. There was no evidence against the men, and the charges were, ultimately, dropped.