Category Archives: Research

The Araucaria team seek wildlife on an island near Brisbane

The Melaleuca Wetlands are adjacent to the beach
The Melaleuca Wetlands are adjacent to the beach

For some years now we’ve been conducting tours to Coochiemudlo Island, an attractive and varied little subtropical  island with long sandy beaches over which thousands of blue crabs march as the tide recedes, rocky platforms, mangroves, coastal woodlands and red cliffs much prized by the Aboriginals, who used the red ochre for body painting and trade with mainland groups. Bush stone-curlews, with their arresting stares, raptors, butterflies, bush-birds, shorebirds and a variety of sea creatures in rock pools all add to the charm of this island, so close to Brisbane yet often so deserted as holiday-makers rush to the far more commercialized Gold Coast.

Unlike most crabs, they travel forwards instead of sideways' often marching across the beach in search of food as the tide goes out: hence the name 'soldier crab.'
Unlike most crabs, they travel forwards instead of sideways’ often marching across the beach in search of food as the tide goes out: hence the name ‘soldier crab.’
There are plenty of bush stone-curlews wandering around the island, and their weird, wild calls at night add to the atmosphere.
There are plenty of bush stone-curlews wandering around the island, and their weird, wild calls at night add to the atmosphere.

Darren and I have recently been employed by Coochiemudlo Coast Care (under a grant from Redlands Shire Council) to conduct a fauna survey o the Melaleuca (tea-tree) Wetlands over four seasons (mid-summer, mid-autumn, mid-winter and mid-spring, with a view to enhancing conservation management plans. We completed the first session in January, with a team of volunteers to help set, check and wash traps (used to capture animals which are promptly released after identification).

The delights of staying overnight, listening to the weird, wild calls of the stone-curlews, watching the sun and moon rise over the waters and wandering safe bush tracks at night are encouraging us to add overnight stays to our island tours. We may also in future involve our tourists in some weed eradication (an on-going threat to the native understorey plants) in conjunction with the excellent programs by Coochiemudlo Coast Care, and spotting species in a monitoring program.  Let us know in comments below or by emailing us at info@learnaboutwildlife.com if interested.

Exploring the Wetlands. Tea-tree wetlands have disappeared from much of their former range on the mainland.
Exploring the Wetlands. Tea-tree wetlands have disappeared from much of their former range on the mainland.
The Melaleuca Wetlands are on the edge of an east-facing beach, and we were rewarded on our very first night by a beautiful moonrise.
The Melaleuca Wetlands are on the edge of an east-facing beach, and we were rewarded on our very first night by a beautiful moonrise.

Results will not be public until completion of the survey, but here are a few photos from our visit, which included live trapping and release, walking the trails day and night and setting motion-sensing cameras.

Bearded dragon eating one of the thousands of cicadas that were calling during the survey.
Bearded dragon eating one of the thousands of cicadas that were calling during the survey.

 

Striped marshfrogs were plentiful at night.
Striped marshfrogs were plentiful at night.
A net-casting spider. Instead of sitting in a large web they make a small one to throw over their prey.
A net-casting spider. Instead of sitting in a large web they make a small one to throw over their prey.

Frugivory and seed dispersal at Araucaria, SEQ

 

Wompoo Fruitdove eating bangalow palm fruits
Wompoo Fruitdove eating bangalow palm fruits

Animals obviously need plants, but many plants also need animals. If all seeds drop beneath the mother tree, they’ll be competing with their mother and with their siblings for light, water, space and nutrients, and there may be heavy shade under the mother. They are also more easily found by seed-eating animals if they are in a big clump  on the ground. The tree has a better chance of contributing to the next generation if its seeds  are spread through the forest (or other habitat) in the  hope that some of the sites are better for germination and survival. Many trees, shrubs, herbs and vines simply scatter their seeds in the wind, but in the rainforest there’s not so much breeze, and when there is, the seeds are likely to hit a neighbouring tree and thus not travel far.

Frugivory (fruit-eating) is obviously useful for the animals that derive the nutrients, and if they also digest the seed (as parrots and many pigeons do) it’s not much good for the plant. If however they only digest the soft parts and regurgitate or pass the seeds through their digestive tracts unharmed (as some of our pigeons do, and also bowerbirds, honeyeaters and many others) they also provide an unwitting service for the tree, vine or other plant they fed on.

I was attracted to the topic because it involves so many disciplines – conservation biology (we can’t think only in terms of conserving species,but need to consider the relationships between them and others they interact with, and are there particular animals that threatened =plants depend on, and threatened animals that depend on particular fruits, especially in lean seasons?), ecology, evolution, animals behaviour and physiology.

A channel-billed cuckoo eating native  figs
A channel-billed cuckoo eating native figs

I’ve been conducting research on frugivory and seed dispersal, especially local birds that eat rainforest fruits, for some years now. One of the most popular fruit in our region – in terms both of of numbers of individual birds and the numbers of species feeding on the fruits – is a native fig Ficus rubiginosa (formerly regarded as  F. platypoda). So why aren’t there more growing around here?

I’m currently looking at this and other local plant species from three angles: (1) what eats them and how frequently? (mostly looking at birds, but other creatures as well) (2) where do frugivorous birds sit when not feeding (and thus likely to deposit seeds) and (3) what conditions do they need for germination and growth?

I do most of the observations alone, but guests on our tours can also assist on  forest walks by helping to find birds that are either eating fruit ( for 1 above) or  doing other things (for 2 above).

For the third aspect of the study, I’ve been germinating seeds in the brush house, but am now about to embark on some experiment field plots. In the photos below, Darren is heeling set up some of these experimental plots which in the future can be viewed by visitors to the Araucaria property and which I hope will help answer some of my queries.

prepare germination plots  OLYMPUS DIGITAL CAMERA

Frugivores other than birds include fruit bats and other mammals, some lizards (especially the larger skinks and dragons), fish (but not many in Australia) and ants, and we’re planning more observations of these.

Amateur naturalists contribute to science

A couple of years ago, Wildlife Tourism Australia ran a workshop in Beaudesert on the role of the amateur naturalist in science and conservation

There has been an interesting example recently in England, with  a gardener showing that garden snails appear to have a formerly undetected  ‘homing instinct.’

School childrfen are now being encouraged to join in the study to confirm this – and see the BBC article ‘Snails have a homing instinct.’