This is the fourth and final in a series observing behaviour of the Australian Brushtail Possum (Trichosurus Vulpecula) when exposed to hen’s eggs.
As previously stated, this is a series of simple high-school type experiments conducted to determine if the possum naturally consumes eggs. Again, note that although a hens egg may seem rather large by comparison to some of our at-risk native species, it is actually very small compared to a kiwi egg.
If you haven’t seen any of these experiments before, it’s probably good groundwork to read the three previous posts at https://coranz.org.nz/do-possums-like-eggs/, https://coranz.org.nz/do-possums-like-eggs-part-deux/ and https://coranz.org.nz/do-possums-like-eggs-part-trois/.
Starting from our main observation that possums don’t naturally touch hens’ eggs, even it an attractant is daubed over them. We have tried an egg together with plentiful supplies of other foods, an egg with but a single dog biscuit (a biscuit that was taken by the first visitor), and finally an egg covered in Golden Syrup – the Syrup was consumed but the egg remained untouched.
Our final experiment involves an egg, some bread and an egg that has been broken open to reveal the yoke. The whole egg is on the left, the cracked on the right:
Our first visitor at 22:33 is drawn firstly to the whole egg:
But now settles down to eat some bread, taking their time over it:
Now interest shifts to the other side and the broken egg:
But no, back to the bread again:
Now some repeated interest in the broken egg, and note still plenty of bread left:
But back to the bread again:
Back to the bread again, but notice this guy is standing on the tub containing the broken egg:
Another visitor comes wandering by, but does not climb on board:
Finally, when our visitor alights, notice the tub and broken egg are nowhere to be seen. This guy was last seen standing on them, and now they’re gone.
Still a slice of bread left, and quite a few more visitors during the night. But the unbroken egg survives for the fourth consecutive night.
The remnants of the tub and eggshell are below:
…and the whole egg remains untouched yet again:
So our overall conclusions after 4 individual experiments over 4 nights in January 2020 have shown so far that possums do not naturally consume eggs. The whole egg involved in this series from day one has survived unscathed, despite having had one night smeared in Golden Syrup – a syrup that the possums consumed with gusto.
Because the tub used to hold the open egg was removed from the table – despite being lightly glued down, we cannot be certain whether its contents were consumed before or after it was removed. The contents were nonetheless gone by morning, but since the broken egg was on the ground anything could have eaten it – or the possum could have consumed it whilst it was on the table.
Overall however, it seems pretty clear that without any attractants, whole hens’ eggs are fairly safe from deprivation by possums.
The whole point of this series of experiments is to document the process, its outcomes and give sufficient information for anyone to replicate it in their own back yard (assuming possums are in evidence).
To be increase confidence in our findings of these rather simplistic observations, all of the above should be repeated with all manner of eggs both large and small, with both thick and thin shells. Naturally we would not want to use eggs from any endangered species, but exotic birds such as sparrow or blackbird would likely suffice.