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Fish
Many of the small fish in Kedron Brook are
introduced. The Gambusia or Mosquito fish was observed in all reaches
of Kedron Brook and was released many years ago. Aquarium fish
(guppies, platys and swordtails) are common in the middle reaches of
Kedron Brook. Notwithstanding this, native Gudgeons, Crimson – spotted
rainbow fish, Olive perchlet and Pacific blue eyes have been reported
from Kedron Brook.
Larger species of native fish are common
along permanent flowing parts of Kedron Brook. Silver perch swim in
small schools close to the surface; they are particularly active in
warmer months when there is some flow in Kedron Brook.
In spring the male jewfish or eel-tailed
catfish builds nests in the sandy shallows by swimming round in circles
to form a circular depression. Once the female has laid her eggs, the
male guards the nest for up to 3 weeks. On hatching, juveniles hide in
aquatic vegetation.
The larger fish probably survive in Kedron
Brook because they are too large to be bothered by the aquarium
species. To date, Kedron Brook appears free of carp and other larger
introduced fish that could jeopardize the survival of the larger native
fish.
Fish most likely to survive in Kedron Brook
are those able to utilise a number of habitats, adapt to change and
tolerate the fluctuating pollution and nutrient levels.
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Amphibians
A decline in frog populations around the
world was noted in the 1970’s. In some cases habitat loss has caused
decline, in other areas the reasons for this decline are less well
known.
Frogs inhabit different types of habitat;
tree frogs, marsh or sedge frogs, and burrowing frogs all occur in the
vicinity of Kedron Brook. The utilisation of breeding areas by the
different groups is not distinct, different species (from different
groups) will use the same breeding pond or habitat.
Frogs tend to be opportunistic – they breed
when there is sufficient water and it is at a temperature that
stimulates their calling and therefore mating. Permanent ponds are not
necessarily required, species will utilise pools of standing water on
playing fields, in parkland and in intermittent drains.
Breeding is successful in these locations if
there is sufficient time for the tadpoles to develop before the water
body dries up. This is then a balance between providing adequate (warm)
water temperatures to facilitate rapid frog development and protection
of the waterbody from predators that would make a quick meal of
emerging froglets.
- General requirements for frogs to breed
- Off-stream habitat
- Appropriate water temperature and
duration of intermittent ponds
- Vegetative protection for emergent
froglets and metamorphs
- Nearby habitat or linkages to habitat
suited to adults of species (various)
Frogs can breed in unlikely locations; many
species will breed in inconspicuous areas unnoticed by human visitors.
The presence of introduced fish and
competition with cane toad tadpoles limits frog breeding in the Kedron
Brook channel. Cane toads tend to “jump the gun” on native frogs by
breeding earlier in the season, often in response to light rainfall
which did not stimulate mating calls in native species. Cane toads are
a tough and adaptable species; toad tadpoles are able to use concreted
drains and other modified structures to breed and develop.
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Reptiles
The specific requirements of many reptiles
and their actual distribution along Kedron Brook are poorly known. Some
species are common and often seen (Eastern water dragon, Water skinks),
others are smaller or more cryptic (prefer to hide) and therefore their
distribution is unknown but they may be quite common along Kedron
Brook.
Because most reptiles are ground-dwelling,
they are vulnerable to predation and death on roads. This problem is
compounded by the tendency of species to “sun” themselves in early
spring on the warm bitumen of roads. As a lot of the reptiles,
particularly skinks and smaller lizards, have a relatively small home
range they are able to reside in small pockets of habitat retained in
the vicinity of Kedron Brook and in urban yards. For some of the
smaller species the trunk of a mature eucalypt may provide an adequate
home range.
Reptiles are often ground dwelling and may
burrow, shelter under rocks, stones and logs, use hollows in trees or
hide under the bark of trees. Many are insect feeders and will
congregate where insects are plentiful (i.e. near the stream). Larger
reptiles tend to be omnivorous (eat plants and animals).
Dragons and water skinks are abundant along
the length of Kedron Brook. They can often be seen resting in sunny
locations on rocks or upper banks of the stream and are quick to
retreat to the waters edge or cover of thick vegetation when disturbed.
Keelback snakes are also relatively common.
An absence of ground cover such as fallen
timber, leaf litter and nesting hollows probably limits the
distribution of reptiles in parklands. Disturbance by dogs and cats may
prevent nesting. Roadways prevent movement from one habitat to another
in urban areas. Despite these conditions, skinks are plentiful in areas
with a ground covering of leaf mulch or fallen timber.
Turtles are common in deeper reaches and in
pools along Kedron Brook. The saw-shelled turtle is the most commonly
sighted, although the Brisbane long-neck turtle has been reported from
Kedron Brook.
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Mammals
Mammals have become severely restricted in
distribution in urban areas. Wallabies and kangaroos have disappeared
from most of the area; road kills have contributed to this.
Bandicoots survive in some of the larger
open forest remnants. They are evident by their diggings, shallow
triangular scrapings on the soil surface. The Long-nosed bandicoot is
common in the Sparkes Hill Reserve and upstream in forest remnants,
where they are active at night and shelter under lantana thicket during
the day
Larger mammals such as wallabies are present
in the uppermost reaches of Cedar Creek (near Mt Nebo) and in the
Enoggera Military Camp (upper reaches of Sandy Creek).
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Possums
Perhaps one of the mammal groups best
adapted to urban life are possums. The Brushtail possum is able to
utilise food (fruit and ornamental species) and nesting resources
(building eaves and roofs) within the urban landscape. This species is
widespread and with the arboreal lifestyle can traverse the urban areas
and roads (via powerlines).
The Ringtail possum is a less common
species; it prefers greater connectivity of the tree canopy than the
brushtail, and is therefore less able to adapt to the fragmented forest
canopies in the urban landscape.
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Bats
Because bats are able to traverse the urban
areas, they can use food and nesting sites in the urban landscape.
Three groups of bat can be identified – the
fruit bats, blossom feeding bats and insectivorous bats.
The most well known are the fruit bats or
flying foxes. They feed in vegetation along Kedron Brook and on garden
trees in surrounding urban areas. Flying foxes visit Brisbane in the
summer months and roost in groups numbering in the thousands.
There are eleven main roosting areas in
Brisbane; one is situated on Sparkes Hill. There are three species that
use the same daytime roost areas, the most common is the Black flying
fox, but the Little-red and Grey-headed flying foxes are also present.
Blossom bats feed on flowering eucalypts, paperbarks (Melaleuca spp.)
and other trees; larger trees provide a more plentiful food resource.
Insectivorous bats are small (microbats),
swift and feed at night. They are sometimes detected by a shadow around
a light or by high-pitched clicking sounds.
Kedron Brook is an important feeding habitat for these bats.
Concentrations of insects emerging from the water are a rich food
source. They feed in urban areas and are considered important in the
control of many insect pests. Insectivorous bats nest in tree hollows
and the reduced number of large trees in the developed environment has
probably limited nesting sites available.
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Birds
Of the fauna occurring along Kedron Brook,
birds are probably best adapted to exploiting resources in the urban
areas. They can cross roads and developed areas thus more mobile birds
are favoured over low-flying birds with short flight distances.
Urban areas favour birds that roost, move or
act in groups. A diversity of birds occur along Kedron Brook.
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Waterbirds
Ducks, waders and species associated with in
littoral zone are included in this group. The mouth of Kedron Brook and
the adjacent Boondall and Moreton Bay wetlands are internationally
significant breeding grounds. Migratory birds such as whimbrels and
sharp-tailed sandpipers gather in large numbers on the margins of
Moreton Bay to feed. Few of these migratory species venture upstream
along Kedron Brook.
Birds that congregate in small groups or
have solitary behaviour (i.e. White faced heron, Little egret, Royal
spoonbill) feed within sections of Kedron Brook. Both remnant natural
sections of the stream and channelised sections are useful as wildlife
habitat.
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Stream margin species
Species commonly encountered along the
channel include the White-faced heron, Pacific black duck, Dusky
moorhen and egrets that hide and feed in the channel, and streamside
vegetation.
Insectivorous birds are attracted to the
insects emerging from the water. They nest in the reeds or grasses
growing next to Kedron Brook. Cisticolas and warblers occupy Bulrush
(Typha orientalis) or Para grass dominated areas along the channelised
sections.
On the drier margins of the streamside
vegetation; finches, wrens and quail inhabit dense swards of grass.
Birds were observed in grassland adjacent to Grange Forest Park and in
overhanging lantana thickets in the upper catchment.
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Forest birds
This group includes the species that live in
forest areas, many are able to use the open parkland and urban gardens
to feed and nest.
A number of forest birds prefer dense cover
and would have once taken refuge in the understorey of dense forest or
shrubby thickets. Clearing of understorey for the formation of
parkland, paths and roads has reduced the cover available to these
species; they are now less common in the landscape due to a lack of
habitat. Silvereyes are an example of forest birds that are still
relatively common in the gardens and in thick vegetation remnants along
Kedron Brook.
Species of forest birds that have declined
in the urban landscape are Bush stone curlew, finches, some
honeyeaters, robins, flycatchers and babblers. Many have lost the type
of habitat or food resources they prefer. For others, fragmentation of
the once more extensive forest areas to small patches has reduced the
available home ranges they would have once defended as large family
groups.
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Hollow nesters
Parrots, lorikeets and rosellas find plenty
of food resources in the urban gardens and public parklands but the
number of tree hollows available for nesting possibly limits numbers.
Different sized and shaped hollows are required for different species.
A list of birds recorded from the local areas and utilising nesting
hollows [tree hollows] is given. Bees, bats, possums, tree snakes,
skinks and lizards also use the hollows.
Hollow nesting birds recorded from Kedron
Brook:
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