Bitterns are an iconic wetland bird which is becoming increasingly rare through wetland loss and predation by mammalian predators.

They are the apex avian predator in many  wetlands and their presence gives an indication of overall wetland condition and health.

I was fortunate that Greater Wellington Regional Council engaged me last year through my small wetland consultancy WetlandWorks to carry out wetland bird surveys on a number of wetlands on the eastern side of Lake Wairarapa. This included Boggy Pond, Mathews Lagoon, Wairio wetland, JK Donald Block and Bartons Lagoon. 

Each trip was 8-10 days duration and we based ourselves at Kilmore Lodge, a great home away from home owned by Wellington Fish and Game. One of my recommendations to the Council was the need to carry out a  bittern survey of all wetlands around the lake to get a good handle on the population and what threats each site was subject to.

The survey, carried out over two weeks in  October and November 2013, focused on  locating male bittern who in spring advertise their presence by making a booming call much like a fog horn. They establish territories in mainly dense raupo and use this call to  advertise their presence to available females and make other males aware not to come near. The main calling periods are one hour either side of sunrise and sunset. Occasionally they boom all night and all day when there is plenty of action on. This requires regular early starts and late finishes for the bittern counters.

During the survey 20 male bittern were recorded booming and their territories plotted on a map. Seventeen of the booming birds were calling from patches of raupo and the other three from scattered wet patches of oioi (jointed rush), closer to the eastern lake edge. 

The main concentrations were around five key sites: Boggy/Mathews/Wairio, Ponui Lagoon, Barrage Gates, south Donald/Mangatete Stream and Bartons/Tauherenikau River mouth.

While bittern are polygamous and males can  attract more than one female to their territory, some males are unsuccessful at attracting any. Other studies indicate the sex ratio is about 1:1 so the total population for Wairarapa Moana and associated wetlands is around 40 birds. A report is currently being prepared for Greater Wellington Regional Council that will discuss how these wetlands can be better managed for bittern.

Bittern Workshop

A “meeting of the minds” for people working on bittern was held at Kilmore Lodge, Boggy Pond, Wairarapa on November 2 last year. This was attended by the DOC bittern scientist from Christchurch, other DOC staff, a university  student doing a doctorate on bittern, and Greater Wellington Regional Council staff.

This was followed by a get together of local people and landowners interested in bittern around Wairarapa Moana. About 25 people overall.

The presentations and discussions that followed focused on the biology of bittern, habitat use and threats from plant and animal pests and was followed by a short trip to the Boggy Pond car park where everyone heard three of the local male bittern booming and advertising their wares.

A great opportunity for everyone to share information on this threatened but still keystone wetland bird.

John Cheyne

Wetland Care members recognise that wetlands are vital to the wellbeing of the 
environment, acting as huge ecological sponges by soaking up pollutants and filtering water before it reaches streams, rivers, lakes, aquifers and the sea.

Our initiatives focus on matters as far-reaching as groundwater replenishment, flood control, nutrient and contaminant management and climate change – all critical factors for the conservation of freshwater and saltwater wetlands and marshes.

We want to preserve and conserve the flora and fauna of our most endangered ecosystem so that vibrant wetlands are our legacy to future generations.

In the heart of the prairies at the height of fall migration, Ducks Unlimited Canada (DUC) celebrated 75 years of conservation

excellence with friends and colleagues from across North America.

A special Top of the Flyways convention took place on October 5, 2013, with events held at the historic Fort Garry Hotel in Winnipeg, Manitoba and at DUC’s national office and flagship interpretive centre at Oak Hammock Marsh.

Business session

Speakers from across North America shared thoughts on DUC’s past, present and future during an informative and inspiring business session. Flyway Showcase

Nearly 900 visitors enjoyed a sunny fall day at the beautiful Oak Hammock Marsh Interpretive Centre to learn more about wetland

conservation. Conservationists of all ages got a hands-on look at DUC’s work and its importance in their lives. From radio telemetry demonstrations to bird identification challenges, critter dipping stations and more, the marsh was buzzing with activity. Plus, the sights and sounds of fall migration provided the perfect backdrop.

The historic cabin that once marked the spot of DUC’s first conservation project at Big Grass Marsh was the focal point for a special donor dedication. The cabin now resides at Oak Hammock Marsh, and a new cairn was unveiled to recognise more than 200 donors who contributed to a special major gift campaign in honour of DUC’s 75th anniversary.

Glamorous Galas and Down-Home dinners

Two fantastic sold-out events capped off Top of the Flyways. a signature gala at the Fort Garry Hotel was a vision of style, while the Marsh Keepers Migration dinner under a tent at Oak Hammock Marsh provided attendees with a spectacular setting to view results of DUC’s conservation work.

Saluting leaders, honouring legacies

Throughout its history, DUC has benefited from many pioneering and visionary leaders. Thirty-eight different men have served in the important and influential position of DUC President. Thirteen of DUC’s living past presidents joined delegates at the Top of the Flyways convention, and were honoured during a special ceremony.

WETmak is a free online Wetland Monitoring and Assessment Kit aimed at groups working on wetland restoration projects in New Zealand. It includes a range of monitoring techniques and methods of assessing the impact of restoration work, all designed to minimise the need for expensive or complicated equipment.

The kit is available in different formats to suit user needs. You can download the entire resource or focus on specific modules. Blank datasheets and report templates can be printed off or downloaded to fill in electronically.

Download WETmak, print out a few datasheets, pull on your gumboots and head out with friends to get measuring. Increasing understanding of your restoration work will bring huge rewards and provide useful information for future planning.

There are 40 Wetlands to visit. DoC in association with the National Wetland Trust has produced a booklet about the 40 wetlands you can visit. 

Pick up a copy at your local DOC info centre or visit the DOC website to view them online.

A feature wetland is Nukuhous Saltmash, Burke Road, Ohiwa Harbour, Bay of Plenty.

Nukuhou Saltmarsh covers about 60 hectares where the Nukuhou

stream enters the Ohiwa Harbour. In 2003 the Nukuhou Saltmarsh Care Group was formed and with the help of the DoC and Environment Bay of Plenty, began a significant restoration and interpretation project.

Extensive plantings, weed and pest control, an overlook, interpretation panels, pottery bird plaques, a short boardwalk and a contemplation bench have made this a pleasant place to enjoy the wetland and listen quietly for fernbird calls (a high pitched single note).

Pest control has boosted fernbird numbers, as well as banded rail, Australasian bittern and waders.

It could have lived here for 60 million years!
Those Aussies are trying to steal our things again!

There have been claims that the Kiwi actually originated in Australia.

 

To make it even trickier it was a New Zealander, Trevor Worthy who’s involved with research at Flinders University in Adelaide, who put this theory forward. Four years ago he discovered a fossil at St Bathans in Central Otago, and he says the DNA shows the kiwi are related to the emu. Not the moa as had previously been supposed as the common ancestor.

 

However Department of Conservation bird expert Hugh Robertson said that for more than a decade established thinking was the kiwi was closely related to the emu. But that did not mean it had flown here.

 

He said it could have been in New Zealand since the land split from Gondwanaland about 60 million years ago.

Before the arrival of the Māori in New Zealand, a subspecies of the Black Swan known as the New Zealand Swan had developed in the islands, but was apparently hunted to extinction. In 1864, the Australian Black Swan was introduced to New Zealand as an ornamental waterfowl, and populations are now common on larger coastal or inland lakes, especially Rotorua Lakes, Lake Taupo, Lake Wairarapa and Lake Ellesmere, and the Chatham Islands. Black Swans have also naturally flown to New Zealand, leading scientists to consider them a native rather than exotic species, although the present population appears to be largely descended from deliberate introductions.

 

With its elegant long neck, the black swan (Cygnus atratus) is our largest wetland bird, around 1.2 metres long and weighing 5–6 kilograms. On the water, it appears all black with a bright red bill; 
however, in flight the bird shows wide white wing margins. It has a bugle-like call, and hisses to defend its nest.

About 100 black swans were brought to the South Island from Australia in the 1860s, and the species has traditionally been regarded as introduced. However, numbers have increased faster than expected, suggesting more birds arrived independently – in which case it should be considered a self-introduced native.

To add to the intrigue, the extinct native swan, mentioned in paragraph one, previously named Cygnus sumnerensis, is now thought to have been the same species as the black swan.

Black swans breed either in pairs or in colonies. Their nests are huge mounds of long foliage, built near lake edges. Females may lay up to 14 green eggs, but six is the average. In colonies, up to 40 cygnets gather in large crèches guarded by a few adults.

Juveniles leave their natal lake and spend several years in estuarine or coastal sites, returning to take up permanent residence once they reach breeding age at between two and four years old. Not all birds breed every year. The oldest known swan in New Zealand was at least 29. Black swans are partially protected, and are hunted in season according to regional limits. About 5000 are shot each year.

Thanks to Te Ara Encyclopedia and Wikipedia.

Eleven volunteers from the New Plymouth branch of PricewaterhouseCoopers spent a day out of the office as they helped replace over 90 stoat traps along the Curtis Falls Track in the Egmont National Park.

The old traps came out of the boxes and new stainless steel ones went in. Replacing a line like this can take a couple of weeks so the volunteers really made a difference. With each person carrying six traps in and another six out as well as some tough climbs along the way, it was a big day.

This trap line protects the whio living along streams and rivers such as the Maketawa and they form a network that covers around 7000 hectares. Last year was a record year for whio ducklings in the Park with 33 ducklings hatching in the wild.

 

Another volunteer, Ian Street enjoys the Onaero Domain where he spends a lot of time at his Onaero beach batch and helps out by looking after a trapline and keeping an eye on weeds in the local reserve.

A whitefaced heron also enjoys the Onaero Domain and batch dwellers say he’s been around for about 14 years. “He had a mate,”said Ian, “but she died some time ago.

Recently though he’s found another.” 

 

The heron seems to know when Ian’s at home. He walks up to the front door and taps on the door. “He visits regularly,” said Ian. “I give him a little bit of fresh mince sometimes and away he goes.”

Whitefaced herons are New Zealand’s most common heron. They arrived from Australia in the 1940s so they’re considered native. This one’s been around long enough to be called a local.

Before human settlement (from around 1250–1300 AD), freshwater wetlands covered about 670,000 hectares of New Zealand. Now it is 89,000 ha – a loss of 90 percent. Fertile lowland swamps have been lost in greater numbers than those that were infertile or at high altitudes.

Wetland importance is often under-rated. Groups like our own DU, Wetland Care and the National Wetlands Trust are working towards reversing this trend.

There is a great diversity of wildlife in our wetlands with more native birds, fish, 
invertebrates and plants than most other habitats, yet many wetland species are threatened with extinction. Wetlands have high recreational values, and perform vital ecosystem services such as improving water quality and reducing flood risks.

They have a big role in managing climate change. Healthy peat bogs are year-round sinks of 2-5 tonnes of carbon per hectare – locking it up in their soil indefinitely.

Wetlands are of cultural and spiritual significance to Maori. They provided Maori with food (wildfowl, eels and other freshwater fish), taro cultivation, harakeke (flax) for weaving and other materials for medicinal, food, building, and craft use.

A plethora of wetland to visit

 

Farewell Spit - at the northern most tip of the South Island is one of our most important wetland areas. Part of the spit forms a Ramsar Wetland site of significance and is an important staging area for migratory shorebirds on the East Asia - Australasia path. Just two hours from Nelson, the area has been a wildlife sanctuary since the 1930s and is a haven for over 90 bird species.

 

 

Whangamarino - 62km south of Auckland is the second largest bog and swamp complex

in the North Island - another Ramsar site. 

Managed by DOC, the 5923ha of peat bog, swampland, mesotrophic lags, open water and river systems, is an important habitat for threatened species like Australasian bittern, grey teal, spotless crake, the North Island fernbird and black mudfish.

Firth of Thames

At the base of Coromandel Peninsula, the Firth of Thames has 8500ha of wide inter-tidal flats which attract thousands of migratory wading birds. Some make the arduous 10,000km journey south from the Arctic in spring and fly north again in the autumn; others fly 1000km north from the braided rivers of the South Island in the autumn and return in the spring.

Wairarapa Moana Wetlands Park

Lake Wairarapa, Lake Onoke and their associated wetlands make up the largest 
wetland complex in the southern North Island, supporting native plants and animals of national and international importance.

The diverse habitats within Wairarapa Moana attract a wide range of wetland birds - about 100 species including international migratory birds.

 

The area is also of national importance to fisheries. Among 10 native species, which migrate between the sea and fresh water, are long-finned and short-finned eel, brown mudfish and giant kokopu.

Lower Kaituna Wildlife Reserve

Northeast of Te Puke, western Bay of Plenty, Kaituna is a reminder of how the country used to be with an abundance of cabbage trees and flax, pukeko prowling through raupo, numerous ducks, shags and pied stilts foraging for food in the waterways.

West Coast wetlands

The South Island’s West Coast has a variety of large and valuable wetlands, including lakes, swamps, fens, bogs, marshes, lagoons,

estuaries and pakihi / poorly drained, infertile land. Most are fully protected and are important breeding grounds for rare species.

 

The only kōtuku / white heron breeding colony in New Zealand is located on the Waitangiroto River close to Okarito Lagoon - north of Franz Josef glacier. The region is one of the last strongholds for the Australasian bittern and a large part of the habitat is suitable for crakes - a rarely seen shy bird.

Ō Tū Wharekai wetland

Ō Tū Wharekai, covering the Ashburton lakes and Upper Rangitata River in Canterbury, is an unspoiled, intact, intermontane wetland system and is nationally important for wildlife.

Otago wetlands

Lake Waipori, Lake Waihola and their associated wetlands are the most significant waterfowl habitat in Otago 40km south of Dunedin. The lakes are shallow and drain through an extensive swamp into the Waipori River and then the Taieri River.

Over 60 species of bird live in or visit the wetland. It is now privately owned by Te Rūnanga o Ngāi Tahu and protected by a QE II National Trust Open Space Covenant.

 

 

The waters, mudflats and marginal vegetation of Southland’s large tidal estuaries and coastal lagoons - Jacobs River Estuary, New River Estuary, Bluff Harbour and Awarua Bay, Waituna Lagoon and Toetoes Harbour - make up the most important bird habitat areas in Southland.

More than 80 bird species have been sighted in the area, 65 of which are dependent on the estuarine environment.

Southland’s estuaries rank alongside Farewell Spit and Lake Ellesmere as the top three wading bird habitats in the South Island.