July 11, 2023

New Zealand's connection to the arctic: waders of Te Waihora | Lake Ellesmere, Summer 2022-23

Summer time is a peak period for wading birds around New Zealand. This is due to the diversity of species that arrive after migrating from the northern hemisphere. Other species that breed locally also come to the lake shores to feed, which creates a unique composition of species from New Zealand and abroad. Most of the "summer migrants" come from the Siberian and Alaskan arctic zone, where they breed. For a long time, the breeding biology of many of these species was unknown,
as they simply left in the Autumn with no breeding, nests or eggs to be found. This mystery was expressed by many cultures, including Māori , with the proverb -
Ko wai ka kite I te hua o te kuaka?
Who has ever held the egg of the kuaka?
The kuaka, or Bar-tailed godwit (Limosa lapponica baurei) is the most common arctic wader in Aotearoa / New Zealand, and so was most notable as a mystery animal.
It is thought that their consistent migration may have even assisted in discovering Aotearoa, as the Māori ancestors observed these birds flying South, and concluded there must be a landing place of some sort in the South Pacific.

Other than the kuaka, there are many other arctic wading birds that reach New Zealand - many of which are seldom observed on iNaturalist. Wading birds (or Shorebirds) are species part of the order Charadriiformes. They are characterized by their feeding habits on shore or wetland areas, where they forage in mud for micro-insects, crustaceans and worms. For many people, these Arctic waders can be easily overlooked, as they are often smaller birds, sometimes with drab plumage, are found in inaccessible locations, and come to New Zealand in very small numbers (often declining numbers too). However, these birds are significant as they make up the avian biodiversity of places such as Te Waihora | Lake Ellesmere. It is a delicate relationship between two environments in the world, as Lake Ellesmere supports these special birds, and it allows them to flourish when they return to their breeding grounds: the arctic tundra. So, the protection of both places is incredibly important for the continuity of these amazing species. It is a fascinating ecological relationship between two opposite sides of the world.

Lake Ellesmere or Te Waihora, is a large coastal lake in Canterbury, New Zealand, south of Christchurch city. It is one of the largest lakes in New Zealand, however it is very shallow. Although the lake is considerably polluted with eutrophication, it supports huge numbers of birds, including waterfowl, shags, grebes, herons, gulls, terns, spoonbills and waders (https://tewaihora.org/about-the-lake/ecology/birdlife/#:~:text=In%202021%20more%20than%2049%2C944,by%20the%20Waihora%20Ellesmere%20Trust.). Over the 2022-23 (from November to April) summer, I visited various sections of Lake Ellesmere 13 times, in my own time and to contribute to surveys of the birdlife. Over these outings, I recorded a total of 14 wader species, and one hybrid taxon.

Locals (breeding in New Zealand)

Pied Stilt | Poaka (Himantopus leucocephalus)
This is the most numerous wader on the Lake, with large groups found wading for food along many of the coasts. I personally counted over 600 at one point, at the eastern mudflats. Pied stilts come to Lake Ellesmere to feed, but breed in adjacent wetlands and inland areas during the winter and spring.
They are native to New Zealand, arriving here from Australia in the 1800s, perhaps correlating with the decline of the endemic Black stilt.

Pied x Black Stilt Hybrid (Himantopus leucocephalus × novaezelandiae)
This is a bird I have seen many times, in small numbers, amongst Pied stilt flocks.
Hybrids are common between these two species, and are a conservation problem for maintaining the genetic purity of the Black stilt - I am unsure if the hybrids are sterile or not. These birds appear as an intermediate color morph between the two species. Pure Black stilts also visit the lake, but are rare.

South Island Pied Oystercatcher | Tōrea (Haematopus finschi)
From my personal observations, this species appears to be more common on local estuaries such as the Avon-Heathcote or Ashley. I have seen odd one at Lake Ellesmere, with larger flocks feeding in nearby paddocks during the winter.

Spur-winged plover (Vanellus miles novaehollandiae)
I observed flocks of these common lapwings along the lakes' edge. They are a common bird, often seen in pairs in wetland areas or paddocks. They only recently started breeding in NZ (first in 1932), coming from Australia, perhaps because the New Zealand environment was altered for western agriculture.
These are notoriously noisy birds and often skittish at the sight of people.

Banded dotterel | Pohowera (Charadrius bicinctus bicinctus)
A common wader to the estuary - large flocks of these birds were present over summer, with presumably most breeding in the local vicinity (e.g. Kaitorete Spit). Some Banded dotterels also breed in the South Island high-country, however apparently fly 1600km west to Australia in the off-season. By mid-summer, banded dotterels have finished having chicks, and are often out of breeding plumage. I observed hundreds of these birds feeding in the mudflats, and also roosting amongst the lakeside vegetation. Smaller numbers are sometimes seen at other local estuaries, however the species is generally declining due to nest predation.

Wrybill | Ngutu pare (Anarhynchus frontalis)
This bird is also fairly common on Lake Ellesmere, although not as common as the Banded dotterel. Up to 60 birds were seen in Nov-Dec along the nor-eastern mudflats, where they are observed to feed along all other species. These are one of the few endemic waders in New Zealand, and are placed in their own genus.

Arctic breeders and the East Asian-Australasian Flyway
The species listed below mostly breed in the arctic coastal tundras of Siberia and Alaska, during the northern summer. Many of these species also use a "flyway", known as the East Asian-Australasian Flyway. This is a strategic route taken by these migrating birds which allows for adequate resting and feeding areas while these birds migrate. Again, this is a delicate chain of environments which require global environmental conservation.

Bar-tailed godwit | kuaka (Limosa lapponica baurei)
Although this is the most common arctic migrant that comes to New Zealand (~75,000), I didn't observe many at all at Lake Ellesmere. There is a chance more of these birds live in the southern perimeter of the lake (which I did not visit)
These birds are much more common on surrounding estuaries such as Avon-Heathcote, and around March-April they migrate to far-eastern Siberia and Alaska for breeding.

Red knot | Huahou (Calidris canutus, subspecies rogersi and piersmai)
These are the second most common arctic migrant to New Zealand (~30,000), although large numbers of these birds are not found at Lake Ellesmere, but rather other locations such as North Island estuaries and Farewell spit. As I spent most of my time at Greenpark Sands, I only occasionally saw these birds, as they would seemingly fly in from elsewhere, feed, and often fly away again. They might also be primarily feeding on the southern coast although it is hard to know considering how large the lake is. The most I saw was a group of 9 in late April, which may be quite late for them to still be in New Zealand. This was evident with some of the birds with a rich red breeding plumage. Apparently two subspecies come to New Zealand, both of which breed in the Siberian arctic.

Ruddy turnstone (Arenaria interpres)
These were reliably seen waders on the Sands of Greenpark, with their unusual stubby form and blotchy colors. Up to 36 were seen here in December. Around a few thousand come to New Zealand each summer, most of which likely leave in April-May. Their breeding grounds are again Siberia, possibly in the same places as the Red knot. Although they look generally unequipped for long-distance flying, they breed extremely north, but can also be found extremely south in summer, as I have observed this species on the Subantarctic Enderby Island.

Red-necked stint (Calidris ruficollis)
These tiny waders are rather common on the Lake shore - particularly at Greenpark Sands. 45 of these birds were seen here in January, although there is probably more that live on the lake. The estimated population that comes to New Zealand is only 50-200, so the lake is very important for this species!
Although they are relatively numerous, they can be very difficult to spot, and often I came across them by realizing I was walking into a flock! However they are relatively wary of people (like most waders at Lake Ellesmere for some reason) and will fly away if disturbed. Most of these birds breed in North-west Siberia.

Pectoral sandpiper (Calidris melanotos)
The first of the two main "sandpipers" which regularly come to Lake Ellesmere. Only a handful of Pectoral sandpipers come to New Zealand every summer, with a decent percentage of these being at Lake Ellesmere. When they arrive, like all arctic waders, they are scrawny and tired after the long migration.
But noticeably, they become rather plump before they leave again, almost resembling a Weka (Gallirallus australis) in shape.

Pacific golden plover | Kuriri (Pluvialis fulva)
A pretty plover that migrates from the arctic. We counted a huge number of these birds a at Greenpark Sands, of at least 67 on Boxing day. Interestingly, they are quite afraid of people on Lake Ellesmere, but I have heard they are completely fearless in other countries. They are also known to feed on the paddocks surrounding Lake Ellesmere, however this behaviors has not been observed for a number of years.

Sharp-tailed sandpiper | Kohutapu (Calidris acuminata)
The second of the two main "sandpipers", and the more common species in New Zealand. Again, inhabits the same habitat of the Pectoral sandpipers, and I occasionally saw them together.

Long-toed stint (Calidris subminuta)
This was the rarest wading bird to be observed on Lake Ellesmere this summer, with it being the second bird to ever be recorded in New Zealand. It was discovered by the Canterbury birder Fraser Gurney right before Christmas. I was lucky to see it a few times. Interestingly, the last one seen was also at Greenpark Sands 20 years earlier! Essentially, it resembled a Red-necked stint in shape, but had the plumage of a Sharp-tailed sandpiper. It stuck around for about a month.

Marsh sandpiper (Tringa stagnatilis)
A single bird made Lake Ellesmere home for a couple months this summer. This species is another vagrant wader to New Zealand with only a few records per year. It is not actually a sandpiper, but part of the genus Tringa, and so more closely related to the "Tattlers". It was quite wary of people and tended to feed with the larger Pied stilts.

Greater sand plover (Charadrius leschenaultii leschenaultii)
This is not a bird I personally observed at Lake Ellesmere this summer but one that was seen a couple times by others. It is a rarer vagrant to New Zealand, with only a couple records a year. They resemble a banded dotterel slightly, but have distinct structural differences. Interestingly, they are not arctic, instead breeding in China and Mongolia.

The importance of the Greenpark Sands Conservation Area
Most of the birds listed above where observed on the Greenparks Sands, which is protected by the Department of Conservation as a conservation area. This is extremely important as this space is one of the few places for birds such as the Wrybill and Banded dotterel to feed in such large numbers. The quantity and presumably variety of food also allows for a high diversity of wading species to visit these shores. Additionally, the plant communities of Greenpark Sands are quite unique and are worth protecting. Other valuable areas of Lake Ellesmere for waders include areas such as Kaitorete Spit, especially the tip.

Posted on July 11, 2023 12:00 PM by noahfenwick noahfenwick | 44 observations | 0 comments | Leave a comment

August 19, 2022

Westport Pelagic - Late July 2022 - Writeup summary

This trip to the pelagic zone off Westport and Cape Foulwind was the first of its kind ever for birding - a brief previous trip in 2002 (?) was much smaller scale and resulted in few birds seen. The boat used was a fishing vessel approximately 12 metres long and 4-5 metres wide, with an adequate open platform for viewing seabirds (and fishing, usually). There was a good group of eager bird-watchers, about 10-12. The boat crew and skipper were really nice guys and ensured everything ran smoothly, so the biggest thanks to them, along with Steve Wood who organized the trip!

The plan was to travel 12 nautical miles off the coast of the West Coast - this was the legal limit for the vessel, likely due to the perimeter of New Zealand waters. From here, it was unknown which birds might be spotted. Anything was game. Which is an exciting but risky prospect. We could see some very rare birds, or nothing at all. Luckily the trip wasn't overly expensive so either way it would be an awesome day out. Some were speculating on the chances of seeing very rare seabirds, such as the Amsterdam albatross (Diomedea amsterdamensis), seen off the coast of Tasmania previously. The elusive Grey-headed albatross (Thalassarche chrysostoma) was another possibility. These are deep-sea specialists however, and the Tasman sea off the coasts of Tasmania was much deeper than those off Westport (we got to waters approximately 150 metres deep; comparatively 12 NM off East coast of Tasmania can be ~2200m deep).


The route taken, recorded by my GPS.

There were two separate trips for 23/07 and 24/07 - I was only on the 23rd. We set out early, leaving Westport harbor at 7:30am. Conditions were apparently good, weather was relatively dry, warm and calm. The sea however, wasn't. It could have been much worse, but it did roll quite considerably - which made sea sickness an annoyance to overcome for myself, and so I was unwell for a large portion of the trip. This didn't stop me from getting the very most of the trip regardless of the circumstances. We spent around 4 hours travelling towards the limit area, spent a few hours out there, and then headed back, arriving where we started at 4:30pm. I was personally impressed by the birds, as I rarely go out on pelagics, but other birders were hoping for some more diversity. Notably, Diomedea (Royal) albatrosses were completely absent, apart from a possible sighting in the distance. Giant Petrels (Macronetes) were also absent. White-capped albatross (Thalassarche steadi) were rather common, along with Fluttering shearwater (Puffinus gavia), and then Campbell albatross (Thalassarche impavida) and Cape petrels (Daption capense). The real highlight was the abundance of Fairy prions (Pachyptila turtur), a bird virtually never seen from a coast apart from a dead carcass. Hundreds of them flew nearby, and many "danced" around the boat, giving great opportunities for up-close viewing and photography. There was even a leucistic individual, a relatively rare condition seen in birds which give a partially or fully white coloration. Westland petrels were also frequently seen, which only nest on the nearby Paparoa ranges - they were absolutely beautiful.

Being on the blurred border between oceanic species, and coastal-mainland species, we also frequently saw Red-billed gulls (Chroicocephalus novaehollandiae scopulinus), Black-backed gulls (Larus dominicanus), White-fronted terns (Sterna striata), and towards the end Australasian gannets (Morus serrator). A highlight was spotting a whale spouting on the ride back, very possibly a Blue (Balaenoptera musculus) or Sei whale (B. borealis), regardless very cool.


Fluttering shearwater in the early morning, with Cape Foulwind in the background.


Campbell albatross with White-capped albatross in the background.

All in all this trip made for a greater weekend of South Island birding. For the future of West Coast bird pelagics it may be more worthwhile to start from a location with better access to deeper water. Jackson's Bay in South Westland could be a viable option, as depths of approximately 1000-2000m could be reached potentially. The limiting factors however could be the inaccessibility of the area, and the possible lack of boats. Deep oceanic waters may not always mean higher seabird diversity, as my knowledge is limited here. But it could work.

Posted on August 19, 2022 01:45 AM by noahfenwick noahfenwick | 24 observations | 0 comments | Leave a comment

July 31, 2022

Vegetation of the Port Hills, Christchurch: Shrublands

The Port hills are a hill range directly South of Christchurch city, Canterbury. They are approximately 25 kilometers in length and reach a height of 573 metres at Coopers Knob / Omawete. As a geographical feature of Christchurch, the hills are greatly valuable as they provide a wide variety of recreational activities and an iconic backdrop to the city. (They also provide useful reference points when trying to navigate some of the deep dark suburbs of Christchurch...)

The vegetation of the hills vary considerably, and provide the foundation for the biodiversity and economy of the region. The hills are a mix of suburbs, grazing paddocks, tussock grasslands, exotic scrub, rock outcrops, forestry blocks, native scrub and indigenous forest. The hills form one side of the Lyttelton crater, the remains of an ancient volcano which now exists as a harbour. Because of this geography, the hill slopes facing the harbour side are steep, whereas the slopes facing away are relatively gradual. The hills can also be divided another way: north and south, with the border between the two regions situated approximately at Dyers pass. The differences between both regions are in altitude, with the lower north side reaching a max height of 499m at Mt. Pleasant. Characteristics of the north side also include a peninsula-like geography, with the hills somewhat isolated between Pegasus bay and Lyttelton harbour, with the settlements of Lyttelton and Sumner on either side. The north side is also more urbanised, with the much larger south side being fairly rural, private and not as popular with recreationalists. The altitude of both regions effects weather somewhat, rain is generally less frequent on the north side, and the south side is wetter. However, there are exceptions with both regions with wet and dry areas occurring in both.

Native scrub

Native scrub is found throughout the hills, especially on south side slopes and gullies with regenerating bush. Native scrub also occurs in small stands on rocky bluffs. Much of the species are small-leaved and divaricating species, but also larger leaf species as they develop into trees.

Native scrub has a biodiversity significance similar to native forests, with a high diversity of native trees giving habitat to native birds and insects.
Shrub species found in native scrub include (39 species, 3 hybrids):
kānuka (Kunzea robusta)
kaikōmako (Pennantia corymbosa) - juvenile form - somewhat divaricating
horopito (Pseudowintera colorata) - becomes large tree
matipou (Myrsine australis) - becomes large tree
kōhūhū (Pittosporum tenuifolium) - rocky outcrops, becomes large tree
akiraho (Olearia paniculata)
pāpāuma (Griselinia littoralis) - becomes large tree
horoeka (Pseudopanax crassifolius) - becomes tree
rōhutu (Lophomyrtus obcordata) - becomes tree
tūrepo (Streblus heterophyllus) - becomes tree
fragrant tree-daisy (Olearia fragrantissima) - divaricating, rare
yellow wood (Coprosma linariifolia) - divaricating, becomes tree
thick-leaved miki (Coprosma crassifolia) - divaricating, drier regions
grey miki (Coprosma dumosa) - divaricating, higher altitude, south
blood wood (Coprosma wallii) - divaricating, uncommon
black miki (Coprosma propinqua) - divaricating
small-leaved karamū (Coprosma x cunninghamii)
rigid miki (Coprosma rigida) - divaricating
Coprosma rubra - divaricating, uncommon
Coprosma virescens - divaricating, uncommon
karamū (Coprosma robusta)
shiny karamū (Coprosma lucida) - wet areas and outcrops
Porcupine shrub (Melicytus alpinus) - divaricating, dry areas
niniao (Helichrysum lanceolatum) - wet areas
korokio (Corokia cotoneaster) - divaricating, dry areas
tarangahape (Carmichaelia australis) - dry areas, can form distinctive stands
poataniwha (Melicope simplex) - divaricating
Raukaua anomalus - divaricating
koromiko (Veronica salicifolia)
Banks Peninsula hebe (Veronica strictissima) - rocky outcrops, endemic to region
tūmatakuru (Discaria toumatou) - dry areas, divaricating
weeping māpou (Myrsine divaricata) - divaricating
(Fuchsia x colensoi) hybrid
tāwiniwini (Gaultheria antipoda) - rare, high altitude
poroporo (Solanum laciniatum) - also found in disturbed and suburban zone
tororaro (Muehlenbeckia complexa) - climber which forms dense shrubs - often a component of drier shrubland communities
mingimingi (Leucopogon fasciculatus) - uncommon
Mountain pinkberry (Leptecophylla juniperina) - dry areas
inaka (Dracophyllum acerosum) - rare, high altitude
Olearia x macrodonta - ?
mountain akeake (Olearia avicenniifolia)
prostrate kowhai (Sophora prostrata) - dry areas, divaricating

Divaricating plants, for those not familiar: https://dunedinbotanicgarden.co.nz/collections/garden-life-article/divaricating-plants-in-new-zealand

Native scrub/shrubland communities

Native scrub differs depending on which part of the hills an observer is situated. Typically, shrubland on the North-east of the hills is a mosaic of shrubs within grass or tussockland. It is characterised by particular species which favour the lower, drier environment. These communities include tororaro (Muehlenbeckia complexa), black miki (Coprosma propinqua), thick-leaved miki (Coprosma crassifolia), kānuka (Kunzea robusta), Porcupine shrub (Melicytus alpinus), tūmatakuru (Toumatou discaria), small-leaved karamū (Coprosma x cunninghamii), korokio (Corokia cotoneaster) and Prostrate kowhai (Sophora prostrata). These shrubland "mosaics" are habitats for native and introduced bird species, insects and spiders. They are also characteristic of the "dryland" Port Hill ecological landscape. These shrublands are generally easy to navigate through.

On the wetter and often darker South-east and west of the hills display a different type of dense shrubland, something I would call "pre-forest shrubland". This is characterised by dense stands of native (and often
exotic) shrubs standing 1-2 metres tall. These shrublands often cloak hill gullies and seemingly random hillsides. They are often regenerating indigenous forest, and increase in ecological value with age. They provide habitat and food sources to a variety of bird and lizard species, and are important due to their significant role in sucking carbon dioxide out of the atmosphere. Species of these communities include natives such as mahoe (Melicytus ramiflorus), kānuka (Kunzea robusta), pāpāuma (Griselinia littoralis), kōhuhu (Pittosporum tenuifolium), Mangrove-leaved daisy-bush (Olearia avicenniifolia), shiny karamū (Coprosma lucida), yellow wood (Coprosma linariifolia), blood wood (Coprosma wallii), Coprosma virescens and exotic shrubs such as Scotch broom (Cytisus scoparius), Gorse (Ulex europaeus) and Himalayan honeysuckle (Leycesteria formosa). Many more species can be spotted among these shrublands, making them always interesting to study.

Those who see the Port Hills as basic grasslands with little variation are mistaken, although understandably. When looking a little more closely, we can see a vast variety of species in the mosaic of shrublands alone, which are essentially 'in-development' indigenous forest, and still host fauna species and a variety of ground ferns and herbs. The vegetation cover of the Port Hills additionally contributes to climate change reversal, in a small way. There is definitely a problem of exotic weed-dominated shrublands on the Port hills, with a few particular culprit species doing the most harm. However, these species are often nitrogen fixers, providing nutrients to the soil and even providing sustenance to native fauna (kererū, Hemiphaga novaeseelandiae, consume broom flowers, and many pollinators find the vast amount of weed flowers useful). I would suggest the seeding of native species underneath exotic shrublands which have reached a maximum height, as these weeds have been shown to assist native seedlings in establishing more valuable native shrubland on other parts of Banks Peninsula (Hinewai Reserve).


Above: A large Prostrate kowhai (Sophora prostrata) shrub on the dry North-east Port hills area. 380m above sea level.


Above: A community of shrubland plants in the Southern Port hills. 460m above sea level.

Posted on July 31, 2022 01:31 AM by noahfenwick noahfenwick | 0 comments | Leave a comment

December 13, 2021

Enderby Island, a surprising summer holiday home for Ruddy turnstone

Original observation: https://inaturalist.nz/observations/69757982

Enderby Island is a predator-free sanctuary island, part of the Auckland Island archipelago in the New Zealand subantarctic region. Among the abundant native and endemic species encountered, I had a small glimpse at a migratory species which also occurs 14,000 kilometres north, breeding in the arctic and coming south to feed in the off-season. Going to Enderby Island last February was part of a youth scholarship trip with Heritage Expeditions to the Snares and Auckland Islands. Scholarships are still being offered (or will be), and if you are eligible and able, I would HIGHLY recommend the experience!


Derry Castle reef.

Derry Castle reef, a rocky peninsula of Enderby Island, was a subdued landscape of boulders, fur seals and rotting kelp, meaning a closer look at the wildlife would be precarious. I decided to proceed further onto the peninsula for a look, as birds here were different to the ones previously seen on the cushy liverworts and prostrate shrubs of the rest of the island. Honourable mentions on the reef include the Auckland Island Banded Dotterel (Charadrius bicinctus ssp. exilis, observation: https://inaturalist.nz/observations/69758062), and were present in significant numbers, blending in seamlessly to their surroundings. Also, Auckland Islands White-fronted tern (Sterna striata ssp. aucklandorna), Antarctic tern (Sterna vittata ssp. bethunei) and Red-billed gulls (Chroicocephalus novaehollandiae ssp. scopulinus) roosted along the boulders. The seagulls here know a much different life than the chip-begging birds of New Brighton over 1000 kilometres away. I was pointed out to two birds resting on the edge of the reef, which like the dotterels, blended into the surroundings. The bright orange legs were a giveaway. These birds were Ruddy turnstones (Arenaria interpres), and now looking back it was quite extraordinary to see them so far south in the sub-Antarctic summer (dreary at best). From May to August, Ruddy turnstone breed in the arctic tundra, which is quite literally the other side of the world. The NZ Birds Online website states that a bird was tracked as travelling 27,000 kilometres in one migration – a remarkable distance for a bird that can weigh no more than a packet of pineapple lumps (Here’s an observation of a Ruddy turnstone almost 80 degrees north in the Nunavut region of Canada https://inaturalist.nz/observations/29146530. For context, Enderby Island is ‘only’ about 50 degrees South!). This global distribution means that conservation of the species relies on international compliance with general habitat protection for waders. Frigid weather aside, Enderby Island must be a relatively safe location to migrate to for these little birds – perhaps further indicating the significance of this island as a beacon of light (not literal, I did not see the sun there) for the Subantarctic’s unique but vulnerable bird species. Ruddy turnstone also occur on mainland New Zealand in larger numbers.

Posted on December 13, 2021 08:51 AM by noahfenwick noahfenwick | 5 observations | 0 comments | Leave a comment

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