New Zealand Wildlife- The Islands (Muter Rahui)

The Islands- Muter Rahui
New Zealand's wildlife has evolved in isolation from the rest of the world over millions of years. As humans settled the country, introduced pests devastated native wildlife and habitats. The Islands animals were defenseless against rats, stoats, dogs, and cats. Many species were lost forever. Luckily, a few isolated islands remained pest free. These islands offered a refuge to species such as the tuatara, Campbell Island teal, and Antipodes Island parakeet. Today, more offshore islands have been cleared of pests to create sanctuaries for the native species. They even target areas of mainland New Zealand for pest removal, creating mainland 'island sanctuaries'.

Tuatara- The name tuatara comes from Maori language, and means 'peaks on the back', referring to the spiny crest that runs along their backs. Tuatara belong to an ancient family of reptiles that have remained virtually unchanged since before the time of the dinosaurs. They are the last of their kind on the planet. Tuatara today only survive in pest-free sanctuaries and off-shore islands, where conservation organizations are helping them through keeping predators out, and through captive breeding programs. They have some unique features. Instead of teeth they have sharp pieces of jawbone which break through the skin inside the mouth. They have two rows at the top and one at the bottom, and can give a powerful bite. Tuatara have no ears but they do have a partially functional third eye, covered by scales in the middle of their forehead. This eye has a retina, lens, and optic nerve. Researchers are still trying to understand how this eye is used. The vertebrae found in the tuatara spine resemble those in fish and some amphibians rather than lizards. Again, they are easily identified by the distinctive ridge of spines down their backs. Males have larger spines than females and can weigh twice as much. Tuatara grow very slowly and can live for a century or more. They have the lowest body temperature of any reptile in the world. Their slow metabolism means that they can survive by breathing just once every hour! Tuatara lay 8-15 eggs in shallow burrows. The sex of the young depends on the soil temperature where eggs are laid. Just one degree warmer can mean it is a male rather than a female. This makes them very vulnerable to climate change. As the planet heats up, there might be fewer and fewer females around to produce eggs. This could spell disaster for the tuatara. Auckland Zoo has bred tuatara for release onto Cuvier, Stanley, and Red Mercury islands. Ongoing conservation work is required to keep these islands free of pests so that the species can re-establish significant populations. Captive breeding takes a lot of patience- eggs take fifteen months to hatch and the babies grow very slowly. Rats love to eat tuatara eggs and babies. An adult tuatara can move quickly and defend itself with its powerful jaws, but its babies are an easy target for predators. The species was completely wiped out on the mainland after settlers brought predatory mammals with them. A conservation program called Headstart has been created by several organizations, including the Department of Conservation, zoos, and Victoria University in Wellington. Headstart aims to save this unique, prehistoric species through breeding tuatara in captivity and releasing them on pest-free island sanctuaries.

Tuatara

Lizards (Mokomoko)- Lizards are common throughout New Zealand. You may see them lounging in the sun, from the coast to the mountains. With more than 70 recognized species, New Zealand has one of the highest diversities of lizards of any temperate area on earth. New Zealand lizards are special. In most other places, lizards lay eggs. Here, all but one species give birth to live young. This adaptation has helped them to survive the cold climate since the time of Gondwana, whereas most other reptiles have disappeared from New Zealand. To make your garden lizard-friendly: plant native shrubs, build rock walls where they can hide, and most importantly, get rid of any rats around your house!

Skinks are smooth-skinned lizards, with shiny scales and short legs. New Zealand has over 30 species of skink. Some are common while others are among the most endangered of all New Zealand's species. The copper skink is the most common in suburban gardens but around Auckland the introduced rainbow skink is taking over.

Copper Skink

Rainbow Skink

Falla's Skink- Falla's skink is found in only one place on earth- the Three Kings Islands off the northern tip of New Zealand. It is one of the country's biggest lizards, growing to 29cm. To survive in its tough environment, it eats just about anything- insects, seeds, leaves, even fish regurgitated by seabirds. There's a serious drawback to living in only one place: a single disaster could wipe out the entire species. So, the Department of Conservation has tight controls to ensure that no predators sneak onto these islands.

Falla's Skink

Chevron Skink- The chevron skink is very shy, and superbly camouflaged, so it's hard to spot. The chevron skinks at the zoo are part of the effort to save this endangered species from extinction. One of them was rescued after being caught by a cat! By studying them in captivity, researchers have developed better ways to monitor and protect these animals in the wild.

Chevron Skink

Moko Skink- Moko skinks are found in the upper North Island. They are present on offshore islands and on the mainland in isolated populations. The most significant in the Auckland region is Shakespeare Regional Park. This fast-moving skink is active during the day and eats small insects, spiders and berries. Like almost all native skinks, Moko skinks do not lay eggs. They give birth to live young, in litters of up to eight.

Moko Skink

Duvaucel's Gecko- New Zealand's largest gecko species, Duvaucel's gecko can grow up to 30cm long, and may live more than 35 years. This nocturnal gecko lives in a variety of habitats, eating large insects such as puriri moth and weta. Although active at night, they also enjoy basking in the sun. Like many other rare New Zealand animals, these geckos were once widespread throughout the mainland. Today, after centuries of predation by introduced mammals, they are mostly restricted to a a handful of offshore islands.

Duvaucel's Gecko

Forest Gecko- The forest gecko is a master of camouflage. Usually shades of brown and cream, it can change its coloring to match the light and shade of the forest floor. This lizard is sometimes called the long-toed gecko. Those toes are useful when it climbs tree searching for nectar and fruit, or to hunt flies. Like all the reptiles, the forest gecko is vulnerable to rats, cats, and other predators.

Forest Gecko

Auckland Green Gecko- Its been skin is not the only colorful thing about this gecko. If you watch closely you might see its blue tongue! Lizards can shed their tails to confuse predators in an emergency, but this gecko only uses that trick as a last resort. It prefers to keep its tail to use as a fifth limb for climbing trees.

The gecko's blue tongue

Auckland Green Gecko

Antipodes Island Parakeet (Kakariki)- This little parakeet is found only on Antipodes Island, an ancient volcano in the Southern Ocean famous for its violent storms. The Antipodes Islands are situated at latitude 50 south, known to sailors as the 'furious fifties' because of its wild winds and mountainous seas. The Antipodes Island parakeet solves the weather problem by nesting underground. Its burrow can be more than a meter long, protecting the nest from the wind. No matter how wild the storms outside, its is safe and warm inside the burrow. The island is rarely visited by people, so they have little fear of humans. They will explore the environment in search of food, scavenging on meat and whatever else they can find. Nobody is allowed to land on Antipodes Island without a special permit. If rats come ashore, this curious parakeet could quickly be wiped out.

Antipodes Island Parakeet

Mammal pests have been eradicated from over 70 islands including Rangitoto and Motutapu in the Hauraki Gulf Marine Park. Through the creation of these island sanctuaries, New Zealanders have become world leaders in pest eradication. In fact, they've become so good at it, the concept of 'island sanctuaries' is being expanded to include mainland 'islands'. Many areas of New Zealand are now being kept virtually free of animal and plant pests to regenerate habitats which can support precious New Zealand species. Already, these sanctuaries are yielding great results, with increasing population of native plants, insects, frogs, and birds. With so much of the natural environment under threat, it's an important step in the right direction. Maintaining these sanctuaries requires a huge amount of support, including hands-on help from volunteers. To find out how you can get involved with a mainland island project near you (if you live in New Zealand), go to www.aucklandzoo.co.nz or www.sanctuariesnz.org.

Island refugees show that the native birds and reptiles can thrive if we keep them safe from predators. These sanctuaries require ongoing care to remain pest free. If a rat or feral cat was accidentally introduced, entire populations of native species could be wiped out in moments, and many years of dedicated conservation activities would be undone. Even seeds, spores, and tiny bugs can wreak havoc on the environment. If you visit one of New Zealand's beautiful offshore islands, make sure you follow the quarantine rules.

Conservation:
Red-Crowned Parakeet (will talk about in another post) on Tiritiri Matangi Island- Auckland Zoo is undertaking two long-term studies with red crowned parakeets here. The first is a nesting study to evaluate reproductive success and chick health, and the second is an annual mist-netting trip for health and disease screening the population. Both projects aim to build on previous work and will provide a long-term dataset needed to understand factors influencing annual variations in the health and reproductive success of this island population. This will also proved important data to assist in future management and conservation efforts in red crowned parakeets.

Red Crowned Parakeet

The Auckland Zoo Horticulture team has been leading fieldwork efforts on Rangitoto Island, helping to rid part of the island from a particularly pesky plant- Rhamnus alaternus
This is commonly known as 'evergreen buckthorn' and is a harmless looking shrub yet an invasive species that if left to keep spreading, could potentially compete with the regeneration of Rangitoto's iconic pohutukawa. Zoo staff have so far spent over 300 hours working alongside Department of Conservation colleagues, with efforts currently focused on targeting the plant's presence beside the main walking tracks.

Pohutukawa

Rhamnus alaternus

The Auckland Zoo is working on many other islands to help control pests, weeds, and increase numbers of endangers species.