Mosquitoes been bugging you this summer ? Stop those sleepless summer nights! Come hear Dr Cameron Webb, Medical Entomologist with the University of Sydney and Pathology Westmead Hospital, speaking on mozzies and mosquito-borne disease at the next Oatley Flora and Fauna Society meeting Feb 23rd (Mon) 7.45pm at Uniting Church Hall Fredrick St, Oatley. For more information on Dr Cameron Webb see his blog at http://cameronwebb.wordpress.com
Dr Tom Grant of UNSW spoke on this subject at the April 28th meeting, a research interest in which he has been involved for 40 years. Click here for details of his publication.
While the International Union for Conservation of Nature (ICUN) classifies the status of the platypus as a ’species of least concern’, he argued that it is more probable that it is vulnerable, due to its dependence on water in which to feed. Spread along eastern Australia from Cooktown and to Tasmania, more investigation is needed to determine the current platypus population. Large numbers were trapped and shot in the 19th century, and there are remaining threats to their continued conservation. They are no longer found in the streams of the Adelaide Hills, Mount Lofty Ranges, and Fleurieux Peninsula in South Australia, where they once occurred.
The Platypus is mobile, reclusive and active throughout the night but most often seen around dawn and dusk. The male has a poisonous spur that it may use in its defence, but is predominantly used against other males during the breeding season. Capture can be risky as they drown if caught and trapped underwater for too long. Radio-telemetry has been used to investigate platypus biology. When foraging, the platypus’s main sensory organ is its bill, much more sensitive than its eyes and ears that are closed when underwater. It has receptors that detect touch, pressure, and electric fields from its prey.
Because platypus populations can be small or spread along rivers, and many animals are mobile, population numbers are difficult to determine accurately. The Australian Platypus Conservancy encourages the public to report sightings of platypus as a way of determining population sizes at particular places. The Platypus is protected, but threats to survival include mortality in illegally set nets and traps, and habitat degradation. Natural and regulated high and low flows ofwater through rivers and creeks can damage nesting and feeding sites.Fossils of ancient forms of platypus have been found in central Australia, but during the time when these species existed the areas were wet, not arid as they are now. The platypus is found in most areas where it was prior to European occupation of Australia, but its populations are probably lower.
Extreme weather events resulting from climate change are likely to decrease the size and distribution of platypus populations. They depend on a stable supply of water, and droughts can reduce current, distribution and numbers. Floods have a detrimental effect on juvenile platypus survival. Foxes are predators and some populations in Tasmania have been prone to a potentially fatal fungal disease causing ulcers and lesions. Use of illegal fishing nets is also a serious problem, as Platypus need to surface regularly to breathe. http://www.platypus.asn.au & http://australianmuseum.net.au/Platypus
Interested in exploring Sutherland Shire? The list of Sutherland Shire’s hidden treasures from Christine Guthrie would be a helpful guide. Oatley Flora and Fauna members were presented with an arm chair tour of these parks on 28 of October by Oatley local and former manager of Bushcare at Sutherland Shire Council Christine Guthrie. She shared her intimate knowledge of Sutherland Shire’s more interesting bushland with a strong emphasis on threatened vegetation and vulnerable habitat. Chris brought to our attention the salt marsh for migratory waders, pockets of littoral rainforest, remnants of turpentine/ironbark forest and an extremely rare beetle (the endangered Menippus fugitivus). The beetles feed on the rainforest tree Celtis paniculata at Grays Point Reserve.
These were only some of the gems discussed, proving yet again how important it is to ensure protection for what little remnant bushland we have. More on plants at: sutherland.austplants.com.au
Click here for full guide OFF Sutherland Hidden Treasures Locations.doc Bonna Point Reserve – Coastal Saltmarsh , Important fish breeding habitat
Marton Park - Freshwater Wetlands
Charlotte Breen Reserve – Kurnell Dune Forest
Woolooware Cycle Track – Saltmarsh and mangroves. Taren Point Shorebird Reserve - important feeding and roosting areas for wading birds
Bass & Flinders Point – Littoral Rainforest, endangered Ecological Community
Darook Park – Closed forest with predominantly rainforest specie
Shell Road Reserve – Remnants of saltmarsh and littoral rainforest on Gunnamatta Bay
Rutherford Reserve – Remnants of littoral rainforest and coastal heath, views to Maianbar and Bundeena
Burraneer Park – Remnants of littoral rainforest and access to the foreshore of Burraneer Bay
Beauford Park – Beauford Avenue, Caringbah. Coastal heath species and views to Royal National Park.
Lilli Pilli Point Reserve – Interesting selection of rainforest species not common in Shire, views to Royal National Park
Grays Point Reserve – Littoral Rainforest and endangered Population of the beetle Menippus fugitivus
Pollard Park – Sydney Turpentine Ironbark Forest
Port Hacking Road Reserve – River-Flat Eucalypt Forest on Coastal Floodplains
Paruna Reserve - Views across the Woronora River to Illawong.
The Glen and Koolangarra Reserves – Swamp Oak Floodplain Forest
Maandowie Reserve – Accessible via an extensive series of fire trails
Prince Edward Park – A large tract of bushland at the rear of the cemetery with extensive views over the Woronora River.
Menai Conservation Park – Shale/Sandstone Transition Forest in the Sydney Basin Bioregion
At the 24th March meeting Sandra Guy, a wildlife rescue volunteer, spoke on flyingfoxes, and their key role in ensuring the ongoing health of ecosystems where animals are every bit as important as plants.
Sandra showed that most types of native forests across the continent depend on flying foxes to do the heavy lifting, pollinating hundreds of species of trees and ensuring genetic diversity and survival of many different types of forest communities. They are a ‘keystone species’, with an essential ecological role without which the ecosystem will collapse.
Many native trees have blossoms that are only receptive to pollination at night, and the only significant nocturnal pollinators are flying foxes. Without them, we will lose the structure that provides the essential microcosms supporting thousands of other flora and fauna species; yet few realise their key role. However, flying foxes are in decline and the main species on the eastern seaboard, the Grey Headed Flying Fox, may be extinct within 20-30 years.
It is time to examine Bats’ roles to see what can be done to save them. They seem so foreign to us, inhabiting the night skies; a realm so diametrically opposed to ours; myths and misunderstandings dominate our attitudes, and misinformation about their disease risk can cause great concern. Only recently have studies led to some understanding of their important role. They have existed for over 55 million years and are one of the most successful and abundant mammals.
There are two main types: the microbats (Microchiroptera) and the megabats (Megachiroptera). They are remarkably intelligent with highly sophisticated social structures. They are more intelligent than dogs and,in captivity, easily learn their own names and the routine of the house or aviary. They breed very slowly as mothers can only raise one pup a year. They form tight emotional bonds, teaching the pups grooming and social skills, until they become independent at about five months. If too long in human care, they become too dependent , and cannot be released into the wild.
They can travel up to 100kms a night foraging for food; returning each morning to an established campsite to rest, nap and socialise during the day. These campsites cause conflict with people, as they can be both odorous and noisy. Unfortunately, bats’ preferred residence is similar to ours, a sheltered gully near fresh water with tall trees and rich soil, protected from disturbing winds. As people clear bat habitat for their homes and farms, flying foxes are quickly losing both food sources and campsites. The problem of conflict with existing campsites is difficult. An experimental initiative to develop ‘replacement’ roost sites has recently commenced, aiming to entice the bats to leave problematic roosts in the middle of urban areas. Flying Foxes by Sandra Guy
Summary of talk given to OFF on 25 November 2013 by Ann Young.
Upland swamps are endangered ecological communities under NSW and Commonwealth legislation, and also under the draft IUCN Red List criteria. They are swampy treeless areas found on the sandstone plateaus around Sydney. Banksia thickets, restioid heaths, cyperoid heaths and sedgelands are found across the swamps, providing a range of ecological niches. High ecological value comes from:
- providing green feed and water to many animals (eg wallabies, birds, snakes, frogs, crayfish)
- supporting stygofauna (groundwater-dependent fauna) such as crayfish, skinks
- being breeding sites for endangered fauna (giant burrowing frog, giant dragonfly)
- releasing clean water to streams especially during dry spells
- storing carbon, probably at similar rates to temperate forests
Upland swamps are resilient to fires. Their dense root mat means they are not easily eroded, and the vegetation recovers quickly. However they are suffering impacts due to the surface disruption caused by subsidence above longwall coal mines. The water table in the swamps drops when the bedrock surface under the swamp sediments is cracked. This means that the sediments dry out, and become more susceptible to damage from fires and to rapid erosion.
Coal leases underlie over 90% of the water catchment areas south of Sydney, and several large swamps have already been damaged by the subsidence impacts, losing water and being invaded by shrub species and having significant erosion channels cut into them.
These are permanent impacts and no practical means of rehabilitation are available. We cannot quantify how much catchment yield is lost by this damage but visible loss of water and sediment dehydration, plus cracking of stream beds, iron staining of water and drying of once-permanent pools strongly suggest significant impacts on water quantity and quality. These swamps need to be protected, both for their recognised ecological value and for their role in Sydney’s water supply.