Oh Zebedee!

Camera traps

Gini had put out motion-sensing cameras a while before, so the first job before doing the vegetation surveys was to retrieve the cameras. The camera points downwards to capture images of anything walking along the ground.

Camera trap (on ploe, left) and bait (right) in heath

Camera trap (on pole, left) and bait (on pole, right) in heath

Fish oil is used in the bait container.

"Remember whale oil? This is better!"

“Remember whale oil? Try this, it’s better”

Once the cameras were retrieved, we helped set up a way of measuring vegetation that could be reproduced over several years.

Vegetation studies

A initial vegetation survey provides a baseline against which to compare future changes.

It’s also apparently been found that revegetation of a degraded area does not necessarily result in birds and other animals returning, even if there is a wildlife corridor from a more pristine area (although that helps). One idea is that when there is, say, mass tree planting, the understorey (where fauna hide or sneak up on prey) is missing or less than useful to the fauna in some way. So measuring present vegetation cover and setting up a way to measure it systematically over time as it inevitably changes, and comparing that to counts of animal populations, would be valuable.

To measure current vegetation type and density, a transect was set up near each camera trap site. First the camera traps had to be located, using GPS measurements Gini took when first placing the cameras. This was sometimes easier said than done, especially in thick heath or forest.

Carrying vegetation survey gear to a camera site

Carrying vegetation survey gear to a camera site

Once the camera was found, north was located and a star picket (aligned north) was driven into ground, and marked off in heights to represent the eyelines of (highest) Bennett’s wallaby (Macropus rufogriseus fruticus, the Tasmanian subspecies of the mainland’s red-necked wallaby); the Tasmanian pademelon (the endemic Thylogale billardierii); the devil and (lowest) the quoll.

Banging in the star picket - Paul (left), Chris (right)

Driving in the star picket – Paul (left), Chris (right)

A 20-metre rope was let out towards the north, and a smaller star picket driven into the ground at the end to steady it. A green pole with the same eyeline marks was placed  at specified lengths along the rope and Chris counted the number of leaves touching the pole at the different eyeline heights. This gave an idea of the density of cover perceived by each type of animal.

Pole of doom



Chris counting leaves touching the pole

Chris counting leaves touching the pole at different eye levels of critters


Looking along the eyelines of each animal gave an idea of how much cover was provided. This was estimated as a percentage using a sheet divided into squares.

Estimating percentage of cover

Estimating percentage of vegetation cover – this is about 50%

The most common types of vegetation was also noted down – we non-botanists used Betty’s cheat-sheets for ID.Vegetation sheet

Chris also looked on the ground for animal holes, such as those of black, burrowing freshwater crayfish, and noted them down.

Lastly, a handheld 3D laser scan of the area was done, using CSIRO’s Zebedee. Readers of a certain age will remember the ‘Magic Roundabout’, a children’s program with said character …

Zebedee of the "Magic Roundabout"

Zebedee of the ‘Magic Roundabout’

Well, it’s no wonder CSIRO called its machine the same name.

Menna using Zebedee on easy terrain

Menna using Zebedee on easy terrain

CSIRO's Zebedee

CSIRO’s Zebedee 3D laser scanning system

We all had a go with Zebedee. However, it’s not so easy when the heath is thick …

Thick heath

or the forest is dense … Dense forest


Dense forest habitatThat cutting grass (the long green stuff in the photos above) is vicious, delivering deep paper-cut-like slashes to the fingers as one falls over and tries to grab something to steady oneself. And another joy of the wet sclerophyll forest is …

Helen has this little number attached to her scalp above the ear. It was well full of blood. Menna took it carefully back to the forest.

Helen had this little number attached to her scalp above the ear. It was well full of blood. Menna took it carefully back to the forest. Goodonya, Menna.


Now a combination of cutting grass and leech gets you this …


At least the gaiters stopped me getting leeched on my feet or ankles. I could now proudly paraphrase Shakespeare: ‘These wounds I had on [Zebedee] day’!

More soon.

4 thoughts on “Oh Zebedee!

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