Introduction

Threatened species are found in a range of habitats across the Northern Territory. Many threatened species can be protected by ensuring these habitats remain in good condition. This involves minimising disturbance in order to allow plants to complete their lifecycles, thus ensuring animals are provided with food and shelter. This profile provides a general overview of the importance of preserving terrestrial and marine habitats for wildlife conservation. More information about specific issues relating to rainforest and wetland habitat preservation can be found in other profiles.

Brush-tail Rabbbit Rat

Photo: © Daniel Pfennigwerth

Terrestrial habitats

Preserving habitat is not just about protecting tree or grass cover but protecting the range of habitat features used by wildlife and the ecological processes that keep the habitat functioning. Many animals find food and shelter in different types of habitats and, for the species to survive, it is important for these to occur in close proximity. Depending on the species this may be within a very small or a very large area. Yellow-snouted Geckos shelter in leaf-litter and feed on insects in patches of bare ground. Suitable habitat for an individual gecko might cover a few square metres. Brush-tailed Rabbit-rats use an area of around one hectare in which they must find hollow logs for shelter and grass seeds for food. Red Goshawks shelter and nest in tall trees and feed in open grasslands or grassy woodlands. The habitat they use can extend over a hundred square kilometres. For such species, destruction of one part of their habitat may make the whole territory unsuitable.

Plants may be even more selective in their habitat needs, requiring specific combinations of soil, nutrient, moisture and light conditions. Luisia Orchids grow on tree branches and need high humidity, but also like to be exposed to the light. In the Northern Territory, these conditions are only found on the edges of rainforests. Bladderworts grow where wet season flooding is followed by dry conditions and thrive in sunny areas. So they grow only in open woodlands or grasslands in drainage depressions and on the edge of floodplains. MacDonnell Ranges Cycads grow in gorges near drainage lines because they need sheltered sites and moist soils.

We do not know why some plants grow only in small areas but they clearly need the specific conditions these areas provide. Giant Sweet Potato is one plant that is predominantly restricted to a small area of Acacia shrublands on red earth soils. The reasons for the restricted distribution are not fully understood, although one limiting factor could be a reliance of germinating seeds on a deep layer of leaf litter and moist soil.

Many vegetation communities in the Northern Territory are still intact and provide the full range of habitat features required by wildlife. However, there are significant threats to habitat condition, especially from fire and feral animal damage. Some entire habitats are threatened. Once habitat is destroyed, reconstructing the exact combination of features necessary to allow the return of threatened species is nearly impossible. To make sure this does not happen, it is important that the habitat of a threatened species is not cleared. Special care should be taken of rainforests and wetlands, which are sensitive habitats that each supports many threatened species.

Preserving habitat around a rock hole

Photo: © Catherine Nano

Marine habitats

The Northern Territory has a vast coastline with unique natural and cultural values. It contains the largest and most intact catchments, coastal wetlands and mangroves in Australia, as well as extensive areas of coral reefs and seagrass meadows. These habitats support a range of threatened wildlife, including six of the seven species of marine turtles, dolphins, sawfish, sharks as well as significant populations of seabirds and shorebirds.

Sea grasses are the only flowering plants that can live under water and are the main diet of green turtles and dugongs. Many smaller animals, such as prawns and fish, use seagrass beds as nurseries or to seek shelter from predators. In addition, seagrass beds have a function as sediment stabilisers and nutrient filters, keeping the water clear from coastal run-off.

Corals are anemone-like animals that secrete a skeleton and live either solitarily or in a colony to form coral reefs. Corals provide food for Hawksbill and Flatback turtles, a species that only nests in Australia. Coral reefs are one of the most biologically diverse ecosystems on earth and form very important habitat for sponges, crustaceans, molluscs, fish, sea turtles, sharks, dolphins and much more.

Sawfishes prefer muddy habitats and frequently enter shallow water and estuaries, where they search for molluscs. There are 5 known species of sawfish in Australia and all occur in the NT coastal waters. However, their habitat preference makes them susceptible to capture and prone to entanglement in all net types.

Marine turtles and migratory birds also use beaches for resting and feed in adjacent coastal waters.

The community can play a role in helping protect marine habitats of the Northern Territory. Help prevent pollution of these environments through responsible disposal of rubbish at all times. Look after beaches which are used by migratory birds, by obeying rules about where dogs are permitted. Keep a lookout for marine animals such as turtles, dugongs and dolphins when boating and keep well away from them if you see them. Obey fishing catch and boating speed limits, keep noise to a minimum and take special care to avoid seagrasses in shallow areas when mooring. Protect turtle nesting beaches such as Casuarina Beach and Bare Sand Island by obeying relevant rules and minimising the use of lights during breeding season, which can confuse hatchlings.

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