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March 2012 Newsletter

General Meeting Times

The next TENPS meeting is on Thursday March 15th. General meetings are held at 7:30 pm on the third Thursday of each month at Marrara Christian College, on the corner of Amy Johnson Avenue and McMillans Road. The general meeting is followed by a chance to meet with other members and access the TENPS reference Library over a cuppa. Bring your plants along to swap, sell or have identified. The guest speaker presentation commences at 8pm. All are welcome. Field trips are usually on the weekend following the General Meeting, details provided in the newsletter or at the meeting.

What’s in Flower?

Pogonolobus reticulatus photographed at the CSIRO fireplots site at TWP in February 2012 by Jon Schatz.

President: Russell Dempster 8983 2131

Vice President: Jude Ebsworth 0437278799

Secretary: Sarah Hirst

Treasurer: Peter Ebsworth

Publicity: Dave Liddle

Publications: Sarah Hirst

Public Officer: Helen Spiers

Librarian: Liz Howells 0415461850

General Committee Members:

Alex Bakunowicz Maxine Atkinson

Webmaster: Alex Bakunowicz

PO Box 135 Palmerston NT 0831

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TENPS 2012 Speaker Calendar

March 15th: Greg Miles - A new look at fire in North Australia'. Greg has a long history of being a ranger in Kakadu National Park, being one of the inaugural rangers when the Park was declared. He no longer works for the Park, but he is currently involved in the successful breeding of Pig-nosed Turtles amongst other activities.

April 19th: Catherine Orme – Volunteering adventure to the Galapagos Islands.

May 17th: TBA

June 21st: Public presentation on the updated ‘Wildflowers of the Darwin Region’ Website following launch

TENPS Committee Meeting Committee meetings are held every second month and members are most welcome to attend. The next committee meeting will be on Tuesday March 20th at 7.30pm. Venue will be Dave Liddle’s home at Savannah Drive Leanyer.

Terminalia pterocarya photographed at TWP during the TENPS field trip on February 18 by Russell Dempster.

February Meeting Report 1: Geoff Martin – Atlas Moths (Attacus wardi)

The Atlas Moth (Attacus wardi) was first discovered in the NT in 1908 by the Butterfly Man of Kuranda and butterfly farm owner, F. P. Dodd when he and son Walter carried out insect surveys around Port Darwin between 1907-9. At that time the coastal zone around what is now Darwin was mostly either monsoon forest or monsoon vine thicket. As a result of bombing during the war and subsequent development, these forests are now gone except for small patches such as that found at East Point and Lee Point. Moths and butterflies are totally dependent on their food plants and in the case of the Atlas Moth a single native species of food plant has been identified. The East Point monsoon forest has been cleared to about ¼ of original size - a significant reduction of habitat for the Atlas Moth’s food plant Croton habrophyllus that grows there. In 1978 a single moth was seen at the Ranger’s house at Black Point. In the 2005-6 Wet season the wing of an Atlas Moth was found on the ground during the construction of the Snake Bay Clinic on Melville Island. Geoff Martin has spent 25 years searching for these amazing moths, and a few years ago he found them at Gunn Point in typical monsoon vine thicket habitat with about 50% deciduous plant species. Small pockets of habitat such as at Gunn Point are extremely vulnerable to clearing for development.

TENPS 2012 Field Trips Saturday March 17th – Gunn Point This trip will check out the habitat of the Atlas Moth Attacus wardi and its host plant Croton habrophyllus. Meet at Howard Springs Nature Park where members with conventional vehicles can car pool with members with 4WD for the trip to Gunn Point. Further details announced at the meeting. Saturday April 21st - Visit the Ebsworth’s place. Sunday April 29th – Fogg Dam Open Day. Sunday May 20th - Howard River Sandsheet - photography opportunity June 2nd & 3rd - Tropical Garden Spectacular Sunday June 24th - Howard River Sandsheet – Public open day to launch the updated ‘Wildflowers of the Darwin Region’ Website

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When Geoff found the caterpillars on an unknown plant at Gunn Point, he took a specimen to the NT Herbarium for identification where he learned it was Croton habrophyllus. Since then Geoff has been attempting to propagate this plant with the idea of creating corridors of the host plant for the moths to spread and recolonise around Darwin. Geoff is now trying to get other organisations such as Darwin City Council, TENPS, and GANT to help with propagation and planting these corridors. Territory Wildlife Park is also interested in how they can contribute to helping the endangered Atlas Moths. The Attacus wardi caterpillar is huge – up to 100mm long and is similar in appearance to the larvae of other species of Saturnid moths (Saturniidae).

Colouration of the caterpillars progresses through a range of colours from ‘salt and pepper’, to white, to greenish white with blue tipped white cilli (above left), to bright green (above right). These colours make them very difficult to see in the field.

Caterpillars are predated by crickets, spiders, wasps and ants. There is high mortality with only about 10% of eggs reaching the cocoon stage. In suitable habitat they are locally common. It takes about 7 weeks for caterpillars to go from egg to the impressive 150mm long cocoon (above). Moths usually emerge in March but after heavy rains that have been seen flying in as early as November and a late as May. Therefore in a wet season there may be 2 periods of egg laying in a year. The adult stage survives for a maximum of 6 days as they have no mouthparts and do not feed. The females reach a wingspan of 170-200mm and are therefore the second largest moth species in Australia. The males usually emerge before the females and they fly every night once emerged seeking females.

When the female (above) emerges from the cocoon, she simply waits on the cocoon for a male to find her. She does not fly until after she is mated, then she only flies between bouts of egg laying. This means dispersal or re-colonisation by the Atlas Moth is likely to be slow. However, moths have not been seen flying before 11pm so if you hope to see one be prepared for a late night! Atlas Moths have a translucent window in each wing which in the females is more or less round and in males is tapered. The antennae are larger in the males and the abdomen smaller. It is likely that the spraying of insecticides during WWII severely affected the Atlas Moth followed by damage to habitat caused by Cyclone Tracy. More recently, clearing for urban development has further reduced habitat for the

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endangered Atlas Moth. Development is likely to continue to be a major threat, especially with Gunn Point recently identified for future industrial development.

Article by Sarah Hirst; photos I. Morris & G. Martin.

The next TENPS field trip will be to the Gunn Point vine thicket to look at Croton habrophyllus habitat and search for evidence of Attacus wardi. Come along to the March meeting for more details….

NT Field Naturalist Club

March Meeting: Wednesday 14 March, 7:45 PM Stephen Richards - Fantastic Frogs of New Guinea. New Guinea is the world’s largest and highest tropical island and the warm wet conditions there have encouraged the evolution of a spectacular diversity of weird and wonderful frogs. Many of these frogs, such as the treefrogs, are closely related to some of our own NT species and some are found in both areas. However in the remote mountain ranges of New Guinea are hundreds of species found nowhere else on earth, and new species are being discovered every year. This talk will present an illustrated overview of New Guinea’s frogs including spike-nosed frogs, biting frogs, and frogs that carry their babies on their back! Stephen Richards is the new Curator of Terrestrial Vertebrates at the Museum and Art Gallery of the NT. His major interest is the tropical herpetofaunas of northern Australia and New Guinea, where he has conducted more than 40 major field expeditions in the last 20 years.

March Field trip: Sunday 18 March – 7.00 PM

Frogging @ Mickett Creek

During the Dry the Mickett Creek area is a dust bowl popular for quad bikers and off road bikers. During the Wet however, it is transformed into a habitat for a large number of frog species. We will learn to recognise the distinctive calls of some of our wetland friends and how to locate and identify them in the field. Meet at 7:00 PM at the corner of McMillans Rd and Stevens Rd (near Knuckey Lagoon). From there we will drive in behind Mickett Creek. Bring a torch. Come prepared for wet weather and wet feet; gumboots are recommended. As frogs are sensitive to insect repellent, please keep your hands clean of repellent. For more information, phone Tissa on 8921 8226.

Book: Top End Wildflowers Wildlife of the Northern Territory: Vol 2

Graham Brown is a well-known and long-serving Northern Territory entomologist who loves to share his knowledge and expertise in the rich and diverse natural history of the Northern Territory. Graham is a former Curator of Entomology and Arachnida at the Northern Territory Museum. This book is written for anyone interested in nature, and learning more. This book gives an introduction to the wildflowers of the Northern Territory's Top End. It includes over 200 species from 79 families. It is part of a series on the flora and fauna of the Northern Territory.

February Field Trip Report – TWP

Sand Sheet & Monsoon Forest

On February 18th 16 TENPS members explored a patch of sand sheet habitat located at the back of the park near the CSIRO fire research plots during the field trip to Territory Wildlife Park.

TENPS members searching for Utricularia species at TWP, photo by Russell Dempster.

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The firebreak proved to be surprisingly rich in Utricularia with 6 species located there by keen eyes. The species found here were Utricularia leptorhyncha, U. chrysantha, U. leptoplectra, U. limosa, U. kamienskii, U. minutissima. Of these species only U. chrysantha had been previously recorded from TWP/Berry Springs.

U. leptorhyncha, U. chrysantha, and U. leptoplectra photographed by Sarah Hirst on 29 February.

Closer inspection of the Dapsilanthus spathaceus / Verticordia cunninghamii / Grevillea pteridifolia / Melaleuca nervosa habitat dissected by the firebreak revealed two more species. Utricularia capilliflora and U. sp. small white, brought the total number Utricularia species for the day to 8.

Utricularia capilliflora photographed on February 18 by Russell Dempster.

Over a cuppa and banana cake the field trippers then voted to visit the TWP Monsoon Forest to see if Croton habrophyllus occurs there, although it is not recorded from TWP. It seemed like ideal habitat but none were located. An unidentified Typhonium species was found growing near the path in the monsoon forest.

The NT Herbarium advises that this it is likely to be Typhonium flagelliforme, but we will have to wait until it flowers next Wet season to confirm.

A monsoon forest Typhonium species photographed by Sarah Hirst during the February 18 field trip.

With 7 of the Utricularia species found being new records for TWP and the location of the Monsoon Forest Typhonium, Sarah (TWP Biodiversity Liaison Officer) was most impressed with the day’s findings! Thanks to everyone who attended.

Article by Sarah Hirst.

Carnivores of the sand-sheets

The sand-sheets of the Howard River catchment

have nutrient poor substrates that vary in

moisture from the extremes of seeping water to

bone dry within an annual cycle. It is not

surprising this harsh landscape supports very

open vegetation with only a few hardy tree

species in the over story. The low diversity in

the over story contrasts with the abundance of

sedges and annual herbs in the ground layer.

Reflecting the low nutrient status, carnivorous

plants are particularly common. On the sand-

sheets near Darwin these carnivores are annual

herbs with traps to ensnare their insect prey.

The sundews or Drosera species have small

sticky hairs while the bladderworts or Utricularia

plants have tiny little bladders. Internal glands

pump water out of the bladders so the traps are

“set” under tension with the door lodged against

a lip of cells. Mechanical disturbance such as the

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movement of a tiny insect causes the bladder

door to open allowing water and material to be

sucked in.

In a nutrient poor landscape, supplementing

requirements for nitrogen and phosphorus by

digesting a few insects makes a lot of sense;

however, perhaps all is not so straight forward.

The vulnerable Utricularia dunstaniae is found in the

Howard sand plains Site of Conservation Significance.

Photo: D.T. Liddle.

A study of the free floating aquatic Utricularia

purpurea from the Everglades National Park in

North America revealed a mix of living and

dead material present, with a lot more than just

insects in the bladders. All bladders on mature

leaves had some sort of photosynthetic tenant

such as blue-green algae, diatoms or green algae.

These photosynthetic organisms have the

capacity to fix energy from sunlight. A suite of

larger organisms included tiny copepods and

ostracods were less common. Of particular note,

around 20% of bladders with foreign contents

present had living rotifers. The presence of tiny

living life-forms suggests that rather than a

simple predator – prey relationship, there is a

mutual benefit to the host plants and the

occupants of the little bladders. The tiny

organisms have a home while the host gains

mineral nutrients and possibly an increased level

of carbon dioxide, the level of which can be a

limiting factor to plant growth in aquatic

environments.

Further reading:

Richards, J. H. (2001). "Bladder function in

Utricularia purpurea (Lentibulariaceae): is

carnivory important?" American Journal of Botany

88: 170-176.

Article by Dave Liddle.

Commelina ensifolia photographed in February at

the CSIRO fireplot site at TWP by Jon Schatz.

Newsletter Contributions

We are always seeking photographs of flowers, plants, and vegetation for the “What’s in Flower” section of the newsletter. News stories, articles, announcements, jokes or anything else that you think would be of interest to TENPS members are also welcome. Please send your contributions to the Publications Officer at sarah.hirst@nt.gov.au on or before the second Friday of each month.

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We invite you to join the growing community ownership of your park through getting involved in our free CID program activities. Meet other like-minded volunteers for a morning of fun and learning. All activities finish with a free sausage sizzle. All welcome, children under 16 must be with an adult, age limits may apply. For more information or to book please email Sarah at sarah.hirst@nt.gov.au

March Sunday 25, 9am-12pm Flight Deck, Woollybutts and Dingoes

Re-mulching, weeding and pruning the gardens around the Flight Deck arena. We’ll then take a short

walk down to the Woollybutts Function area to do some more of the same in the Bushtucker garden.

Weeding, pruning and general landscaping in the dingo exhibit, clearing the moat of weeds and

planting out propagated plants to extend this habitat to the front of the enclosure and create a

beautiful retreat for our furry friends.

Join us for a combination of re-mulching, weeding, fertilising and pruning the gardens and display

areas at the Flight Deck, Bushtucker Garden and Dingoes. Enriching the lives and homes of our star

performers.

April Sunday 15, 9am-12pm Monsoon Forest and Walk-through Aviary

Collecting leaf litter and mulching in the main Walk-through aviary and a couple of the smaller exhibit

aviaries followed by weeding and a treasure hunt for rubbish through the Monsoon Forest.

Sunday 29, 9am-12pm CSIRO Fire research plots / Botanical Activity Centre

Learn a bit about the research that is being carried out at the Park by CSIRO. Meet some of the

scientists working on the fireplots and give them a hand with removing weeds from the study areas.

Here’s an opportunity to talk to experts who are researching the impacts of fire on Top End

landscapes and the effect that it has on the flora and fauna of this region.

May

Sunday 13, 9am-12pm Billabong Spend the morning at the Billabong, cleaning up the Pelicans island, removing aquatic vegetation,

clearing the overflow and pruning trees. Be prepared to get slightly wet, but that’s cool.

Sunday 27, 9am-12pm Grass identification and Woodland seed collection

Collecting and identifying grass and Acacia seeds for future propagation and revegetation projects

around the park. This is a great opportunity to learn how to identify the native grasses and many

Acacia species that are native to this region. Discover the secrets to successful seed collection and

storage.

June

Sunday 24, 9am-12pm Bird and Butterfly Garden Main station Help us create a bird and butterfly friendly garden in the picnic grounds at the Main station. Learn

about some of the native plant species that are a food source for our native birds and butterflies.

Take home some tips on how to effectively bird and butterfly-scape your backyard.

Territory Wildlife Park Community Involvement Day Program

Calendar of Events

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TO:

Sender:

PO Box 135 Palmerston NT 0831

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