Argentine Ants on Tiritiri Matangi
Argentine AntAuthor: Chris Green, Department of ConservationDate: From the Supporters of Tiritiri Matangi Archives, Dawn ChorusHeader photo: Chris GreenSupporters of Tiritiri Matangi Archives, Dawn Chorus, Autumn 2000 Ten years ago a new immigrant species slipped quietly into New Zealand, arriving in Auckland and establishing itself in Onehunga, just prior to the Commonwealth Games in 1990. That immigrant was the Argentine ant (linepithema humile) and initial surveys quickly revealed it to be quiet widespread. It was decided that there would be no welcoming committee dishing out pesticide sprays, or free food laced with insecticide, as has been the scenario when insect pests such as fruit fly or tussock moth arrived. Those entomologists “in the know” however, knew that New Zealand had come of age with this arrival of one of the world’s most invasive pest ant species. The Argentine ant is a native of South America and has been invading overseas countries, including North America, Hawaii, South Africa, and Australia, for more than 50 years. Since its arrival in New Zealand, Argentine ant has spread to many areas in the Auckland Region, established itself in Tauranga and Morrinsville, and has recently been reported from Christchurch, Gisbourne and west of Dargaville. Now it has been found on Tiritiri. Argentine ants are small-two to three…
The tīeke/saddleback scheme and what it can teach us
Celebrating 40 years of tīeke/saddleback on Tiritiri MatangiAuthor: Kay Milton and John Stewart, Biodiversity Sub-CommitteeDate: May 2024, Dawn Chorus 137Header image credit: John SibleyWhen tīeke/saddleback arrived on Tiritiri Matangi in 1984, it was truly the beginning of an era. Not only did they bring new sights and sounds to enrich the experience of anyone visiting the Island, they also marked the beginning of a project that would consume many working hours over the subsequent 40 years and which continues to this day. In 1984, only a small fraction of the original bush cover remained, and the planting programme was only just getting underway. This meant there were very few sites where tīeke could nest, so boxes were provided for this purpose. There were 360 boxes, but regularly monitoring this number proved difficult, and, as the bush planted between 1984 and 1994 has matured, an increasing number of ‘natural’ sites has become available. Between 2008 and 2012, the number of boxes was reduced to a level that could be more easily managed by a team of volunteers. Since then, it has been relatively stable at around 150-160 boxes. Barbara was tasked with the responsibility of checking the boxes once a week during the season, and twice a week when eggs were hatching. This was quite a laborious task, which required a great deal of dedication, attention to…
Celebrating 40 years of tīeke/saddleback
Celebrating 40 years of tīeke/saddleback on Tiritiri MatangiAuthor: Stacey Balich, GuideDate: May 2024, Dawn Chorus 137Header image credit: John SibleyIn 1984, 24 tīeke/saddleback from Cuvier Island were released on Tiritiri Matangi. They quickly established themselves with the help of nest boxes, roost boxes and regenerating bush. This year marks the 40th anniversary of their arrival, and, to celebrate this, Barbara Walter shared with me her experiences and stories from the early years. Dr Tim Lovegrove (Auckland Regional Council Heritage Department scientist) coordinated the translocation from Cuvier Island. The 24 tīeke, comprising six breeding pairs and 12 juveniles, came from five different areas of Cuvier Island and had distinct dialects. In order to preserve these distinctions, they were released in five different areas on Tiritiri Matangi: Bush 1, Bush 2, Wattle Valley, Bush 21, and Bush 22 (see Figure 1). At the start, 360 nest boxes were made by the North Shore Forest and Bird branch, coordinated by Eric Geddes, who used to travel to the Island on a small runabout from Army Bay. There were some differences in how the boxes were made. Some were short and some were long, both types having a V shape for the opening. Later a grill was added to the opening to prevent mynas and ruru from getting in, especially ruru, as they were getting in and…
Soil: what helps create and maintain it
Soil: what helps create and maintain itAuthor: Libby May, GuideDate: September 2024Healthy soil is fundamental to our continued healthy life. It provides plants, filters and manages the volume of rainwater, hosts an enormous biodiversity both above and below ground and it can tell us about our past as well as protect our future. It’s a huge carbon pool, absorbing carbon dioxide from the air – 1,500 billion tonnes of carbon globally – almost three times more carbon than in all above ground biomass including trees, shrubs and grasses. According to the Land Care Research Soils portal, each year unsustainable land management around the globe is responsible for around 24 billion tonnes of fertile soil being contaminated, washed off the land or blown away by the wind. In New Zealand it’s 192 million tonnes a year. (1) It’s not a speedy process, creating healthy, rich, fertile soil. Its origins start with bare rock and sediment surfaces being weathered and disintegrating under the influence of climate. Over time the surface becomes available to vegetation, lead by lichens (of which we have an abundance on Tiritiri Matangi) which will root in any cracks they can find such as the greywacke we see on the Wattle Track. A thin layer of vegetation will gradually build up and in the fulness of time start decomposition which in turn produces organic acids. These help…
Spring has definitely sprung!
Spring has definitely sprung!Author: Neil Davies, GuideDate: September 2024Photos credit: Neil DaviesSunday 1st Sept. On Sunday Mary-Ann and I were over on the island checking tracking tunnel cards as part of our on-going monitoring programme. Nothing untoward and just the usual critters showing up on the cards – footprints of birds, weta, wētā punga, skinks, tuatara and Duvachel gecko to name a few. However, it was impossible not to be taken by the level of bird song, even in the middle of the day, which indeed sounded like the ‘dawn chorus’. There were lots of encounters with kōkako, hihi, korimako, tūī, pōpokotea and tīeke as well as several tuatara spotted outside their burrows. I think they were celebrating the return of sunshine and mild temperatures after the heavy rain, thunder and lightning from the weather ‘bomb’ that passed over on Saturday night. Things definitely seem to be warming up and Spring has definitely sprung! Kōwhai and karo are still blooming prodigiously all over the island and the ground is now being carpeted with yellow flower petals and the deep crimson colour of the karo flowers. It also looks like it’s going to be an exceptional year for harakeke (flax) with a huge number of flower spikes and the first flowers already opening (I haven’t seen any on the mainland yet). Rewarewa has started to flower too which also seems…
Tropical newcomers thrive as our sea temperatures continue to increase off Tiritiri Matangi
Tropical newcomers thrive as our sea temperatures continue to increase off Tiritiri MatangiAuthor: John Sibley, GuideDate: August 2024Photos credit: John SibleyOnce again in 2024 the winter minimum sea temperature off Tiritiri Matangi stayed two degrees higher than the historical recorded average 50-60 years ago. At the same time two warm water species from the tropical North took advantage of this and were able to dominate the local marine ecology to the detriment of its indigenous residents. The first species to appear in 2024 was the tropical toxic cyanobacterium Okeania, which now forms a permanent part of the seagrass community around the Gulf. Aided on by the half million tonne sewage spill from Parnell in October last year, Okeania grew rapidly in January to smother vast areas of seagrass. Left: Leaving a few strands on a microscope slide one sunny afternoon resulted in a tangled mass four hours laterRight: Off Tiritiri Matangi the seagrass beds were affected from the wharf to Hobbs Bay, with slimy fingers (picture above) breaking away and floating up to the surface just where swimmers love to come and cool down after a hot days walking.Off Waikehe Island the council were called in to clear the resulting half metre deep layer of black slime off the beaches. Off Tiritiri Matangi the seagrass beds were affected from…
Seabird Counting
Seabird CountingAuthor: Roy Gosney, GuideDate: August 2024Photo credit: Oscar Thomas There is no doubting the success of Tiritiri Matangi in preserving bird species that have principally succumbed to human devastation. This achievement however provides no indication of how more successful species are faring. Enter the ubiquitous seabirds whose status is a good indicator of overall ecological health, given their existence on the margins of land and sea. A little-known project on Tiritiri Matangi has been Seabird Counting, the aim of which is to help fill this gap in our knowledge. Seabird counting has been an annual event taking place between September and January and is in its 12th year. Mike Dye did this for the first 10 years ably describing his experience in a 17th May issue of Guidelines. I assisted Mike over the last 5 years until we were joined by Rachel Taylor. Rachel and Mike, now no longer in Auckland, left a vacuum that I, in a mad moment, agreed to fill. Consequently, I started the 23-24 season on my own, but thanks mainly to Mike’s article, a number of people have come forward and we’ve built a good team comprising: Scott Camlin, Bethny Uptegrove, Sue Beaumont Orr, Yvonne Vaneveld and Julie Benjamin. The target species are primarily Red-billed Gulls (RBGs), Black-backed Gulls (BBGs), White-fronted Terns (WFTs) and Pied Shags (PS) because…
Birds—The Formula 1s of the Animal World
Birds—The Formula 1s of the Animal WorldAuthor: Malcolm Pullan, GuideDate: July 2024Photo and video credit: Neil DaviesHave you ever marveled at the extraordinary journeys that some birds go on when they’re feeding or migrating? Have you ever wondered how birds are able to fly through the forest so quickly, yet not crash into things? Have you ever wondered how it is that many birds can remain on the ground as a car is approaching and then quickly escape at the very last second? You haven’t? Oh well, neither had I until a few years ago. Now, though, I think about it almost every time I see a bird. For I now know that underpinning these observations is something quite special about birds that explains so much about why birds are the way they are. Birds are hot(1). In fact, they’re the hottest vertebrates (2) around. You and I maintain a more or less constant body temperature of around 37°C. That’s fairly typical for a mammal. Birds also maintain a relatively constant internal body temperature—except theirs is likely to be in the range of 39– 43°C, i.e. quite a bit higher than your average mammal. Now you don’t need to know much chemistry—or baking for that matter—to know that when you heat things up, chemical processes speed up. This is what happens in birds. Stuff happens more quickly. For instance, reaction times are faster and muscles can work harder.…
Highway robbery
Highway robberyAuthor: Jonathan Mower, GuideDate: July 2024Photo and video credit: Jonathan Mower This short video clip captures a moment of interspecies interaction when a toutouwai/ North Island robin came across a tīeke/ North Island saddleback that had captured and killed a wētā. The toutouwai was a much more dominant bird and harassed the more timid tīeke, eventually causing the tīeke to abandon its prey to the toutouwai which snatched it and flew away. The small wattles and timid nature may mean the tīeke was a young and inexperienced hunter because I have previously seen tīeke aggressively dispatch large prey including hura/giant centipedes and wētā. By nature, the toutouwai are often bold and aggressively territorial toward others of their own kind but here we see them interacting and showing dominance over a very different species.
Tuatara—Ancient Escape Artist
Tuatara - Ancient Escape ArtistAuthor and photo credit: Jonathan MowerDate: June 2024Tuatara are the sole surviving member of an entire order of animals, the Rhynchocephalia, whose ancestors separated from those of the Squamata (lizards and snakes) in the late Triassic period, so about 240 – 250 m years ago. Reaching total lengths of over 600mm, they are the largest of New Zealand’s endemic, terrestrial reptiles (some males recorded at a hefty 1.1kg), with their ridged tails accounting for slightly more than half of that total body length. Muscular and powerful, the tuatara’s tail plays a significant role in balancing locomotion, storage of body fat, and displays of dominance or physical defence. To a superficial observer, the tuatara might be described as resembling a lizard, but in reality, there are significant differences between tuataras and other reptiles. One similarity, however, is the ability to sever deliberately and then regrow part of their tail. The practice is known as caudal autotomy and is a defensive mechanism that allows them to escape harm or predation. Why would you intentionally drop off part of your body? On their island sanctuaries, kahu/harriers are significant predators of tuatara. They are also predated by other birds including karearea/falcons, kōtare/kingfishers, and possibly, ruru/ morepork and karoro/black backed…