Let's work smarter- not harder! Talking Trad
September 2015
Tradescantia fluminensis or Trad is a perennial plant which send its vegetative shoots along the ground and forms roots at the leaf nodes. These vegetative shoots run over each other and create a mat structure which in favourable conditions can be as thick as 600 mm. Even a thin mat of Trad shades the ground so strongly that no seed fallen into this darkness will germinate and prosper. This could create a serious problem in the bush regeneration environment in Darvall Park if left untreated.
The other problem besetting many bush sites in the midst of urban areas is re-infection of already regenerated areas. The re-infection comes in several ways. One of the very common ways for weeds to spread is by storm water bringing plant debris and seeds from surrounding streets. It is impossible and impractical to stop the water, but the storm water can be filtered.
Tradescantia fluminensis or Trad is a perennial plant which send its vegetative shoots along the ground and forms roots at the leaf nodes. These vegetative shoots run over each other and create a mat structure which in favourable conditions can be as thick as 600 mm. Even a thin mat of Trad shades the ground so strongly that no seed fallen into this darkness will germinate and prosper. This could create a serious problem in the bush regeneration environment in Darvall Park if left untreated.
The other problem besetting many bush sites in the midst of urban areas is re-infection of already regenerated areas. The re-infection comes in several ways. One of the very common ways for weeds to spread is by storm water bringing plant debris and seeds from surrounding streets. It is impossible and impractical to stop the water, but the storm water can be filtered.
Powerful birds in Darvall Park
Powerful Owl (Ninox strenua)
His or her deep double hoot "woo hoo" has been heard at night in Darvall Park often but here is the evidence that Darvall has sufficiently quiet areas where this magnificent raptor can take a rest. Photo kindly donated by A. Jain.
His or her deep double hoot "woo hoo" has been heard at night in Darvall Park often but here is the evidence that Darvall has sufficiently quiet areas where this magnificent raptor can take a rest. Photo kindly donated by A. Jain.
Nest-boxes for Native Birds
Nest-boxes provide a substitute for a lack of natural hollows in trees where hollow nesters such as Parrots, Owls, Pardalotes and Kookaburras can hatch their eggs and care for their chicks until fully fledged. Nests or nest-boxes are not bird houses and very few birds have any need for nests as such outside a breeding season. However, a nest site is often the focus of a breeding territory, and may be used regularly year after year. A lack of appropriate nest sites will limit the distribution of species.
Many native Australian species are under threat of extinction. Most of those threats are linked to the disappearance of habitat and in case of some birds, a loss of suitable nesting sites. One of the very serious nesting problems is the lack of old trees with natural hollows in its trunks and branches. Natural hollows in trees take time to develop. Hollows suitably spacious for birds to nest in may take more than one hundred years to develop. Unfortunately, trees one hundred years old and older are not welcome in urban environments. They are too unstable and pose a danger to people and their property. All hollow nesters are under stress from a lack of suitable nesting places, but the most threatened bird species out of hollow-nesters are the big parrots such as Black Cockatoo and large Owls. The danger is, as the large birds live for many years and the food is available we will still see them around, but only as an ageing population which, unable to breed effectively, will slowly disappear into extinction.
With the old trees gone, nesting opportunities are gone and if we don’t take preventative action our spectacular birds will also be gone. Building, placing, monitoring and maintaining well designed nest boxes may help to mitigate the effect of human industrial development.
Building the nest-boxes;
Several different materials have been experimented with to build nesting boxes including ceramics and PVC tubing. However, for the time being, timber seems to be the material of choice. Wood is reasonably strong, lightweight and provides very good thermal insulation. The ideal and most durable material is 20 mm. marine plywood but other wood can be used such as sawn plantation or recycled wood as long as the timber is not chemically treated. However, nest-boxes out of soft plantation timber will have to be painted on the outside with acrylic paint for weather protection. Generally, it is best to use the thickest and most insulating material. A nest-box should keep the birds dry, exclude any draft and
be open-able for annual cleaning, maintenance and for eviction of undesirable species.
Placing the nest-boxes;
Choosing the site is very important. The nest-boxes should be suspended from the fork in a sturdy tree that has a trunk of at least 200 mm. in diameter. The spot for the nest-box should be in semi-shade to shade (from midday sun), and about 3.5 to 4m from the ground. This height is manageable for maintenance and stops most intruders. It is important that there are no branches below the nest-box on the tree which would allow intruders (including humans) easy access to the nest. Also, even very thin branches close to the entrance of the nest-box are not desirable because they could be used by Common Mynas or Starlings to perch on and harass the intended occupants. The box should be facing east to benefit from warming rays of sunshine in the morning and be protected by the trunk of the tree from summer’s afternoon scorcher. The nest-box should be very securely attached to eliminate any independent movement or vibration caused by wind or possums jumping around.
Monitoring - observing what is happening around the box. The most important task is to keep the introduced Common Mynas, Common Starlings or feral bees out of the nest-box. Common Mynas are extremely aggressive and are capable of chasing out of nesting sites birds of their size and even small mammals such as the Sugar-glider. Part of the problem is the fact that the Common Myna and Starlings start nesting 2-3 weeks earlier in the spring and can breed twice a year. Feral bees and European wasps are a more diffused enemy but statistics show that up to 20% of nesting boxes are taken up by bees and wasps.
Maintenance;
Keeping a successful nest-box comes with responsibility. At least twice a year the keeper has to climb up and tend to the nesting site.
The first time is during the month of August to prepare a box for the coming nesting season. That involves, cleaning the box inside (only Crimson Rosellas do it for themself), unblocking the entrance, painting the box on outside (if necessary) and tightening the anchor cables to restore nest-box stability. If the nest box is attached to the dead tree or man made structure the attachment can be permanent.
Most of the native birds in normal circumstances will nest once in the year. The nesting season begins in second half of August when pairs of birds start looking for suitable nesting site. The true nesting, (laying of eggs ) may start in October and it takes until the end of January when the new generation of birds fly out. This is the second time the keeper should attend the nest-box because from the moment the last fledgling leaves, the nest will be unoccupied for seven months. This is the time when it’s very important to loosen the anchoring cables to prevent them cutting into the growing tree trunk and it maybe prudent to totally block the entrance of the nest-box to stop its misuse by Mynas, Starlings, Feral bees and European wasps. From then on everything settles down until nature moves full circle and everything is ready for a new and exiting nesting season to start again.
Many native Australian species are under threat of extinction. Most of those threats are linked to the disappearance of habitat and in case of some birds, a loss of suitable nesting sites. One of the very serious nesting problems is the lack of old trees with natural hollows in its trunks and branches. Natural hollows in trees take time to develop. Hollows suitably spacious for birds to nest in may take more than one hundred years to develop. Unfortunately, trees one hundred years old and older are not welcome in urban environments. They are too unstable and pose a danger to people and their property. All hollow nesters are under stress from a lack of suitable nesting places, but the most threatened bird species out of hollow-nesters are the big parrots such as Black Cockatoo and large Owls. The danger is, as the large birds live for many years and the food is available we will still see them around, but only as an ageing population which, unable to breed effectively, will slowly disappear into extinction.
With the old trees gone, nesting opportunities are gone and if we don’t take preventative action our spectacular birds will also be gone. Building, placing, monitoring and maintaining well designed nest boxes may help to mitigate the effect of human industrial development.
Building the nest-boxes;
Several different materials have been experimented with to build nesting boxes including ceramics and PVC tubing. However, for the time being, timber seems to be the material of choice. Wood is reasonably strong, lightweight and provides very good thermal insulation. The ideal and most durable material is 20 mm. marine plywood but other wood can be used such as sawn plantation or recycled wood as long as the timber is not chemically treated. However, nest-boxes out of soft plantation timber will have to be painted on the outside with acrylic paint for weather protection. Generally, it is best to use the thickest and most insulating material. A nest-box should keep the birds dry, exclude any draft and
be open-able for annual cleaning, maintenance and for eviction of undesirable species.
Placing the nest-boxes;
Choosing the site is very important. The nest-boxes should be suspended from the fork in a sturdy tree that has a trunk of at least 200 mm. in diameter. The spot for the nest-box should be in semi-shade to shade (from midday sun), and about 3.5 to 4m from the ground. This height is manageable for maintenance and stops most intruders. It is important that there are no branches below the nest-box on the tree which would allow intruders (including humans) easy access to the nest. Also, even very thin branches close to the entrance of the nest-box are not desirable because they could be used by Common Mynas or Starlings to perch on and harass the intended occupants. The box should be facing east to benefit from warming rays of sunshine in the morning and be protected by the trunk of the tree from summer’s afternoon scorcher. The nest-box should be very securely attached to eliminate any independent movement or vibration caused by wind or possums jumping around.
Monitoring - observing what is happening around the box. The most important task is to keep the introduced Common Mynas, Common Starlings or feral bees out of the nest-box. Common Mynas are extremely aggressive and are capable of chasing out of nesting sites birds of their size and even small mammals such as the Sugar-glider. Part of the problem is the fact that the Common Myna and Starlings start nesting 2-3 weeks earlier in the spring and can breed twice a year. Feral bees and European wasps are a more diffused enemy but statistics show that up to 20% of nesting boxes are taken up by bees and wasps.
Maintenance;
Keeping a successful nest-box comes with responsibility. At least twice a year the keeper has to climb up and tend to the nesting site.
The first time is during the month of August to prepare a box for the coming nesting season. That involves, cleaning the box inside (only Crimson Rosellas do it for themself), unblocking the entrance, painting the box on outside (if necessary) and tightening the anchor cables to restore nest-box stability. If the nest box is attached to the dead tree or man made structure the attachment can be permanent.
Most of the native birds in normal circumstances will nest once in the year. The nesting season begins in second half of August when pairs of birds start looking for suitable nesting site. The true nesting, (laying of eggs ) may start in October and it takes until the end of January when the new generation of birds fly out. This is the second time the keeper should attend the nest-box because from the moment the last fledgling leaves, the nest will be unoccupied for seven months. This is the time when it’s very important to loosen the anchoring cables to prevent them cutting into the growing tree trunk and it maybe prudent to totally block the entrance of the nest-box to stop its misuse by Mynas, Starlings, Feral bees and European wasps. From then on everything settles down until nature moves full circle and everything is ready for a new and exiting nesting season to start again.
Interesting species!
Cabbage Palm Tree (Livistona australis)
A tall mop-headed palm, locally common in gullies and rain forest situations. In the1920’s, Judge Barron Field wrote: "These trees once characterised the neighbourhood of Port Jackson; but they have long since been exhausted." The reason for this was, that all parts of the palm were used by settlers; the trunks for building, fencing and pig troughs, the pith and fruit for pig-feed, the mature leaves for thatching, while those leaves just beginning to expand were plaited into the popular cabbage tree hats. Most popular was the cabbage the growing bud in the heart of leafy head. Darvall Park has no fully grown trees only 3 year old seedlings. The tree in the photo is one of several specimens in Oatlands.
(Text: Native plants of Sydney, Les Robinson 1991).
EVOLUTION IN YOUR BACKYARD
Have you seen an Eastern Water Dragon or a Brush Turkey in your backyard lately? Do the mating calls of Peron’s Tree Frog in a downpipe of your house drive you mad? Whilst there are other creatures moving into urban areas, these three are very visible examples of species making a fast evolutionary leap that enables them to cope with the stress of living in urban areas. In every animal as in humans, the clue to surviving is being able to recognise and quickly react to danger. During threatening situations the brain gives the body the message to release a stress hormone epinephrine (adrenaline). This hormone puts the whole body on alert instantly. The heart beats more rapidly and strongly, the eyes dilate to allow more light in, breathing quickens, and the activity of the digestive system decreases to allow more blood to go to the muscles. Adrenaline is also called the fight or flight hormone. In bush creatures it’s mostly flight. This state of high alertness "stress" if it lasts for prolonged periods of time is very damaging to the immune system, brain and reproduction. That’s why creatures of all kinds wanting to live amongst us city dwellers and thrive in an environment full of unnatural light, noise and vibration, have to adapt and lower their sensitivity. It is not easy because coping with life in the city requires adaptations that run counter to evolutionary history. Few species can adapt and for those who can, the rewards are plentiful in being able to exploit all the un-utilised hunting grounds of urban areas free from the challenges of competitors.
George Divisek
Black Faced Monarch (Monarcha melanopsis)
Black Faced Monarch is a migratory bird from the North seeking rainforest environments. It can fly as far as Papua New Guinea in autumn and winter. How exciting that Darvall Park still can support this exotic beauty!
Photo taken by Phil Kent.
East Coast Free Tailed Bat (Mormopterus norfolkensis)
The East Coast Free Tailed Bat is one of the species of micro-bats moving in smalls groups up and down the East Coast. During the night, they fly fast above the tree tops or around the forest edges catching small insects. During the day, they roost in hollows or under bark of large trees, sometimes taking shelter under or around human structures. Lack of membrane between the legs and tail makes them easy to identify as the Free Tailed Bat. Despite their Latin name, they have never been found on Norfolk Island. Unfortunately we still do not know much about this elusive creature and they are listed as vulnerable, namely due to loss of habitat.
The East Coast Free Tailed Bat is one of the species of micro-bats moving in smalls groups up and down the East Coast. During the night, they fly fast above the tree tops or around the forest edges catching small insects. During the day, they roost in hollows or under bark of large trees, sometimes taking shelter under or around human structures. Lack of membrane between the legs and tail makes them easy to identify as the Free Tailed Bat. Despite their Latin name, they have never been found on Norfolk Island. Unfortunately we still do not know much about this elusive creature and they are listed as vulnerable, namely due to loss of habitat.
New faces on the block!
Native animals looking for new ground and new territory sometimes stumble into the Darvall Park. How exciting if the park could sustain them! It could be an indication that the bush regeneration program in the park is heading in the right direction.
Black-tiled Native Hen (Gallinula ventralis)
Also called Waterhen or Swamphen. In pairs or flocks
frequenting swamps, lakes, the reed-beads and grassy
plains. It is an active bird flicking its tail as it runs
nimbly in and out of reeds, and flying only when hard
pressed. Feeds on grass, aquatic plants and small animals.
Black-tiled Native Hen (Gallinula ventralis)
Also called Waterhen or Swamphen. In pairs or flocks
frequenting swamps, lakes, the reed-beads and grassy
plains. It is an active bird flicking its tail as it runs
nimbly in and out of reeds, and flying only when hard
pressed. Feeds on grass, aquatic plants and small animals.
Banded Rail (Rallus philipensis)
Also called Buff-banded Rail or Painted Rail. Singly or in pairs,
frequenting scrub and rank herbage in swampy localities,
and the margins of streams. Often it feeds in the open but is timid,
and dashes into dense cover at the least disturbance. Feeds on insects,
seeds and small freshwater molluscs and green shoots of various
plants.
frequenting scrub and rank herbage in swampy localities,
and the margins of streams. Often it feeds in the open but is timid,
and dashes into dense cover at the least disturbance. Feeds on insects,
seeds and small freshwater molluscs and green shoots of various
plants.