• Abstract and Figures
• Public Full-text

BACKYARD BIODIVERSITY OUR NATURE: KOALAS 1 Backyard Biodiversity ECOSYSTEMS DIVERSITY ECOSYSTEMS The Gold Coast is one of Essential for a healthy planet the most biodiverse cities in Australia. Our native plants and wildlife are essential to our environmental, social and economic health and wellbeing. Backyards are an important part of the Gold Coast’s natural landscape with more than half of the SPECIES DIVERSITY city’s native vegetation on private properties. Essential for healthy ecosystems If you have a backyard, courtyard or a balcony you have the opportunity to support our native plants and animals by providing habitat for our diverse native wildlife. GENETIC DIVERSITY Essential for healthy species 1 Threatened species Biodiversity is reduced when species become extinct. Plant and animal While the categories and specific definitions used differs between State species which are at risk of extinction are known as threatened species. and Federal legislation, in both cases the status indicates whether a species still exists and how likely it is to become extinct. Threatened species can be identified by their conservation status which is specified under both Federal [Environment Protection and Biodiversity Gold Coast Conservation Act 1999 (EPBC Act)] and State [Nature Conservation Act 1992 (NC Act)] legislation. On the Gold Coast, species which are locally significant are known as City-wide significant (CWS) species. These species CWS A range of factors is used to assess a species’ conservation are important because they may be threatened, restricted to status including: the Gold Coast, or at the edge of their geographic range. • the number of individuals remaining You and your backyard can contribute to supporting threatened and • the overall increase or decrease in the population over time CWS species by creating and restoring habitat in your backyard. • breeding success rates and known threats. Throughout this booklet, Threatened, Near threatened and CWS species are identified using the symbols shown below. They are accurate at the time of printing. Threatened species MOST LIKELY TO LEAST LIKELY TO EXTINCT BECOME EXTINCT BECOME EXTINCT EPBC Act Ex Wx CE E V CD Extinct Extinct in Critically Endangered Vulnerable Conservation the wild endangered dependant NC Act PE E V NT LC Presumed extinct Endangered Vulnerable Near Least in the wild threatened concern BACKYARD BIODIVERSITY: Our Nature – Koalas 3 OUR NATURE: KOALAS The koala is one of the most loved and recognisable of Australia’s unique animals. The Gold Coast supports some of the most important koala habitat and populations in South East Queensland. These populations occur in over 32,000 hectares of habitat within both public and privately owned land. Over As well as being listed as a vulnerable species under both Koalas occur in only Federal and State legislation, koalas are also a City-wide 5500 4 AUSTRALIAN significant species (CWS). Community involvement is essential Estimated number of to ensure their long-term survival on the Gold Coast. There are koalas within the STATES many conservation measures we can all take on our properties, Gold Coast in 2019. QLD, NSW, VIC and SA. and in our neighbourhoods, to protect and support koalas. Take action in your backyard • Protect established koala habitat and food trees. AUGUST to • Restore habitat on your property through assisted DECEMBER natural regeneration. • Plant koala food trees and other habitat trees. • Be a responsible pet owner. Our koalas are • Help them to move safely across the landscape and AUG – DEC through your backyard. SMALLER Is peak breeding than those found in season, so koalas • Take care driving on the roads, especially during southern states. are on the move. breeding season. • Report and help manage vertebrate pests. • Report koala sightings. BACKYARD BIODIVERSITY: Our Nature – Koalas 5 About Koalas The koala is one of Australia’s largest arboreal (tree-dwelling) marsupials and like much of our fauna, endemic (native and restricted) to our country. The koala occurs widely across eastern Australia, covering coastal and inland areas of Queensland, New South Wales, Victoria and a small area in South Australia. Their range is restricted to the presence of eucalypt forests and woodlands that contain a select group of trees on which they feed. A fussy eater Koalas are obligate folivores - which means they predominantly eat only one type of leaf. Their leaf of choice is Eucalyptus however they do feed on related genera, including Corymbia, Melalueca, Angophora and Lophostemon. They are one of only three mammal species that can survive on a diet of eucalyptus leaves. Greater Gliders and Ringtail Possums are the other species. Eucalypt leaves are high in fibre and low in protein. They also contain a range of chemicals which make them unpalatable or toxic to most mammals. Koalas have many adaptations to cope with their unique diet. They have specialised teeth to nip the leaves from the tree and then shred them finely. They also have a specialised digestive system which includes a caecum. The caecum is an important part of the digestive system of mammals that eat a lot of plants. It contains millions of bacteria which help to breakdown the leaves. The liver is also very important as it detoxifies the oils and other compounds in the leaves. Koalas only eat leaves and their leaf of choice is Eucalyptus BACKYARD BIODIVERSITY: Our Nature – Koalas 7 Due to the low-energy content of Eucalyptus leaves, Koalas spend around 18 to 20 hours of each day resting in order to conserve energy. They also have a very slow metabolic rate so their food can be retained in their digestive systems for long periods of time to allow as much energy as possible to be extracted from it. Koalas normally obtain sufficient water from the 200 to 500 grams of leaves they eat per day. However, they do come to the ground and drink from pools and streams when conditions are hot and dry. Preferred koala food trees Koalas feed on a wide range of Eucalyptus species across their wider distribution. However, within local areas koalas mainly feed on a small number of preferred species. On the Gold Coast, there are Swamp Mahogany Forest Red Gum Eucalyptus robusta Eucalyptus tereticornis more than 35 species of eucalypts. Of these, five are known to be preferred koala food trees. Tallowwood Small-fruited Grey Gum Grey Gum Eucalyptus microcorys Eucalyptus propinqua Eucalyptus biturbinata BACKYARD BIODIVERSITY: Our Nature – Koalas 9 Supplementary food trees STRINGY BARKS Although koalas have their preferred food trees, there are other tree species that provide supplementary food resources including species of iron barks, stringy barks and smooth barks. Tindale’s Stringybark Thin-leaved Stringybark Eucalyptus tindaliae Eucalyptus eugenioides IRON BARKS Narrow-leaved Ironbark Grey Ironbark Red Mahogany Broad-leaved White Mahogany Eucalyptus crebra Eucalyptus siderophloia Eucalyptus resinifera Eucalyptus carnea BACKYARD BIODIVERSITY: Our Nature – Koalas 11 SMOOTH BARKS AND HALF BARKS Other important trees for koalas In areas where the preferred food species occur in adequate abundance, koalas will utilise a wide range of other species for shelter. Koalas shelter in a variety of species to regulate their body temperature. Narrow-leaved Red-gum Smooth Barked Apple Eucalyptus seeana Angophora leiocarpa Spotted Gum Brush Box Koala Corymbia citriodora Lophostemon confertus resting in a Forest Oak (Allocasuarina torulosa) BACKYARD BIODIVERSITY: Our Nature – Koalas 13 KOALA SHELTER TREES Pink Bloodwood Blackbutt Hickory Wattle Black Wattle Corymbia intermedia Eucalyptus pilularis Acacia disparrima Acacia melanoxylon Forest Oak Swamp Sheoak Swamp Box Broad-leaved Paperbark Allocasuarina torulosa Casuarina glauca Lophostemon Suaveolens Melaleuca quinquenervia BACKYARD BIODIVERSITY: Our Nature – Koalas 15 Keen sense of Not just a pretty face hearing to help communicate Koalas are well adapted to their life in the trees. They have muscular with other bodies, very strong forelimbs and soft, textured gripping pads and long, koalas over long distances sharp claws on their paws to help them grip and climb. Even though they don’t have a tail they have excellent balance. Their paws have a number of unique features to help them climb and Highly grip. Both the front and hind paws have five digits each. The front paws developed have two fingers opposing the other three, giving the koala its distinctive sense of smell to detect toxins “double thumb”. The hind paws have a clawless opposable big toe to in leaves and help with gripping, while the second and third toes are fused together to detect scent form a double-clawed (syndactylus) toe used for grooming and removing marking from other koalas pests such as ticks. In South East Queensland, adult koalas grow up to around 70 centimetres in length from head to bottom and weigh, on average, Thick, woolly fur between five and seven kilograms. Adult males are generally for protection considerably heavier than females and can reach up to nine from rain and extreme kilograms in the Gold Coast area. temperatures Speckled rump makes them harder to detect from the ground Clawless opposable big The front paw with its toe and double-clawed distinctive “double thumb” (syndactylus) toe BACKYARD BIODIVERSITY: Our Nature – Koalas 17 Behaviour Koalas are mainly nocturnal and tend to be most active around dawn and dusk (crepuscular). They are solitary animals. In areas where adequate habitat remains, koalas establish and occupy individual home ranges, typically only interacting with other individuals when breeding. Reproduction and lifespan Females are generally sexually mature and capable of breeding from around two years of age and can produce a maximum of one young per year. However, a breeding rate of one young every two years appears to be more common in the wild. The koala breeding season in South East Queensland commences around July-August and can extend through until around April-May. Koalas are usually born between November and February.

Load more

  39

Copy Link