Native birds

Some native birds you might see or hear

• Tūī

  Tūī grow up to 30cm in length. The male tūī weighs approximately 120g and the female approximately 90g. Tūī are mostly black in colour but in the light have green, bluish-purple and bronze colouring with a lacy collar of white filaments and white throat tufts. Tūī have black legs, a curved black bill and a white wing bar. Both sexes of tūī look alike. Juvenile tūī are a dull slate black colour with glossy wings and tail, a greyish-white throat, and lack the white throat tuft or poi that are a distinctive feature of an adult tūī. Tūī breed between October and February. Native plants are a good source of food for them at this time of year.

  Listen to a tūī song [MP3, 2.2 MB] (courtesy of Department of Conservation).

  Tūī in Hamilton city

  Many tūī visit the city over winter (May to August) looking for food. Scientists believe they come to feed on the nectar of exotic species of trees that flower over winter. They currently commute from up to 20km away, and return to their breeding sites outside the city. 

  Until recently, over the past 100 years, only one tūī fledgling had been recorded in Hamilton. Tūī nesting success is very low because of predators that have been introduced to New Zealand. In recent studies, only about a quarter of monitored nests fledged young. This is mainly due to ship rats and possums, which climb trees and invade tui nests, eating the eggs and chicks.

  To improve nesting success, Waikato Regional Council carries out annual pest control (rat and possum) at key breeding sites in the "Hamilton Halo " area before the tui breeding season. Other native species of birds (such as bellbirds), plants and invertebrates will also benefit. Having more birds survive to maturity in the bush means that there will be more dispersion into surrounding areas where tūī have not often bred, such as Hamilton.

   
• Korimako (bellbird)

  Bellbirds are endemic to New Zealand (only found in New Zealand), and until recently had not been seen in Hamilton for more than a century. The bellbird is known in Māori as the korimako, makomako, or rearea.

  Bellbirds are approximately 20cm long. The male bird is olive green in colour with a yellow-green belly while the female bellbird is brown with a thin white stripe running from the bill across the cheek.

  The bellbird breeding season is approximately September through to February. Bellbirds tend to nest fairly high up in trees, and prefer trees with dense foliage for cover. A good range of food sources is required in the near vicinity, with flowering/fruiting times spread throughout the breeding season. Bellbirds are strongly territorial during the breeding season.

  A pair of bellbirds maintain the same breeding territory year after year. The female makes the nest and lays three to five eggs. Both parents feed the chicks, which fledge at about 14 days old. A pair can raise two broods in a season. The oldest bellbird recorded lived to over 8 years.

  Bellbirds collect nectar and fruit from a variety of native plant species. Bellbirds feed on nectar, fruit and insects, with insects being particularly important to females and chicks during the breeding season. They often feed high up in tree canopies but do come down to flax and native fuchsia. 

  Bellbird song

  Bellbird song varies enormously from one place to another and also varies according to season/behaviour and the sex of the bird. Bellbird song comprises three distinct sounds resembling the chiming of bells. They sing throughout the day, but more so in the morning and evening. The alarm call is a series of loud, rapidly repeated, harsh staccato notes.

  Bellbird alarm call [MP3, 286 KB] (courtesy of Department of Conservation).

  Bellbird repetitive call [MP3, 634 KB] (courtesy of Department of Conservation).

  Bringing korimako back to Hamilton city

  Before human arrival the bellbird was found throughout New Zealand but had either disappeared or drastically declined by the mid-late 19th Century.

  In 2009 a multi-agency programme led by Landcare Research and the University of Waikato, released bellbirds from Auckland’s Tiritiri Matangi and Tawharanui bird sanctuaries into the Hamilton Gardens, with the aim of building up a breeding population in the city.

  Preparatory work for the release involved pest control at the Hammond Park bush area upstream of the gardens. Supplementary feeders were used at the Hamilton Gardens to help the birds adjust to their new surroundings. 'Acoustic anchoring' was also used at bush sites near the gardens to help stop them flying away from the central city – this involved playing recorded song from the bellbirds’ home dialect for 10 days.

  To monitor how many bellbirds stayed around after the release, about 20 birds had radio transmitters attached, with a two-week battery supply. The Ornithological Society’s Waikato branch was also invited to monitor birds at the feeders in the gardens by recording leg bands.

  Why were bellbirds released in Hamilton?

  It’s all part of the bigger picture of urban restoration ecology. Bellbirds are good pollinators and are an important part of an urban eco-system. The return of birds like tui and bellbird to Hamilton will complement other biodiversity restoration initiatives such as the Waiwhakareke Natural Heritage Park, and gully restoration projects occurring in Hamilton.

  Why are some bellbirds wearing leg bands?

  Leg bands were attached to a group of bellbirds that were moved from Tiritiri Matangi and Tawharanui to their new home in Hamilton. The leg bands are used to help monitor bellbird sightings and track their movement.

  How do you read leg bands?

  Leg bands are read from top to bottom and left to right. Birds may have more than one coloured band on each leg, it is important to note the colour and order of each band so that we can identify the bird from our database.
• Kererū (wood pigeon)

  The kererū is New Zealand’s only surviving native pigeon. They are long-lived birds that breed very slowly, and they are currently fighting for survival.

  Kererū are now the only birds left that are capable of swallowing fruit greater than 12 mm in diameter and dispersing the seed again whole. This means the future of our native trees is closely linked to the survival of our kererū.

  Recent studies have shown that despite the fact that kererū can live between 15 and 20 years, the average lifespan in some parts of the country is between 1½ and 5½ years. The biggest threats to kererū are impact injuries with windows and cars, closely followed by habitat loss, predation and illegal hunting.

  What can you do to help our kererū?

  Consider planting trees in your garden to encourage kererū to visit. Kererū have adapted their diet over the years to eat plants that are both native and exotic.

  Examples of these include: Wineberry, Coprosma, Cabbage Tree, Broadleaf, Pigeonwood, Southern Rata, Puriri, Miro, Matai, Kowhai, Wattle, Scottish Broom, Tree Lucerne, Holly, Laburnum, Virgillia, Silver Poplar, Flowering Cherry/Plum, Pear, Willow and Rowan.
• Ruru or morepork (owl)

  Moreporks are iconic New Zealand birds that are instantly recognisable from their distinctive calls. They are known to inhabit many different habitats in New Zealand, however, comparatively little is known about urban morepork populations.

   

  Ruru in Hamilton City

  The overall goal of the possum and rat control that we do in bush areas near the city is to improve the survival of all our native birds, and we were very pleased to learn some good news about the morepork population in Hamilton, as the report below from the Ornithological Society of New Zealand says.

  2011 Ornithological Society of New Zealand survey

  The Ornithological Society of New Zealand (OSNZ) is committed to encouraging, organising and promoting the study and enjoyment of birds, and has 17 regions across the country.

  As part of the Waikato region’s 2011 programme, a morepork survey of Hamilton was organised as a fun way to involve and expose many different people to ornithology. It was also the first time such a survey had been conducted in a New Zealand city.  Fortunately, Moira Pryde from the Department of Conservation had developed a method for surveying moreporks that community groups could use, though it had so far been untried.

  The survey was organised primarily by Dai Morgan, OSNZ, and Andrew Styche (Department of Conservation). Twenty different Hamilton sites were selected and, for five nights between 24-28 October 2011, people went to each of these sites to record moreporks for an hour after sunset.

  Findings

  Preliminary findings were quite encouraging – 16 of the 20 sites detected moreporks at least once over the five night survey. Of these 16 'successful' sites, 13 detected moreporks on two different nights and five managed to have birds counted every night, despite some noisy traffic and one evening of weather that was less than pleasant.

  Moreporks were detected at the 13 sites by the second night of the survey, suggesting that a bird is likely to be counted quickly. On at least one of the nights the birds were counted at the beginning of the survey, suggesting the counting was being done at the ‘right’ time of the night.

  What does it mean?

  But, what does this all mean? Well, before we did the survey, there were no other studies that had attempted to count moreporks in a New Zealand city. This makes comparisons with other areas a little difficult. However, moreporks are classed as ‘widespread and moderately common’ throughout the rest of New Zealand and this also appears to be true for Hamilton too! The fact that we detected moreporks in so many sites is, perhaps, not so surprising as we intentionally chose areas that should support them; e.g., gullies, parks and other green spaces.

  It is likely that the moreporks detected at sites on most or all nights are probably resident there. Birds only detected at a site on one or two nights may have been transients that were just passing through, or perhaps the count site was on the edge of their home-range, so they only visited the area where they were counted sporadically.

  It is impossible to determine this level of detail from the data we collected; however, the fact that a bird was detected there is good enough for our purposes. When we repeat the survey, it will be interesting to see if those sites still have birds detected.

  We also found that  11 of the 16 ‘successful’ sites had two or three birds present. This is great news as it implies that breeding within the city is probably occurring too (especially when two or more birds were counted at a site during most/all nights). Looking at how successful these breeding birds are would be very interesting, and may be picked up by a post grad student at some stage - the data we have collected would be very useful in such a study.

  Where to from here?

  The first thing that we’ll do is fully analyse the data. We are sure that more interesting findings will come out of this with a closer inspection. Next, we’ll look to put the study within the public domain through publication in New Zealand’s only bird focused scientific journal, Notornis. This study was done under the OSNZ umbrella, and other regions across the country have expressed an interest in doing surveys in their cities - this will be great for future comparisons.

  It was amazing to see how many people were keen to give up their time each night to count moreporks, and thrilling that people brought their kids along to help out too. Officially, we had 56 people on the list, but I know partners, friends and relatives were brought in as well - so it was a big effort. We counted 20 sites on five occasions - that is 100 hours of work! It is really encouraging that Hamiltonians have a keen interest in conservation, which can only result in good things for the future!

  For more information, please contact Dai Morgan (magpie.morgan@gmail.com) or Andrew Styche (astyche@doc.nz).