This is the third in a series observing behaviour of the Australian Brushtail Possum (Trichosurus Vulpecula) when exposed to hens’ eggs.
A simple high-school type experiment is conducted to determine if the possum naturally consumes eggs. 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.
According to that font of all knowledge Wikipedia: “The kiwi lays one of the largest eggs in proportion to its size of any bird in the world, so even though the kiwi is about the size of a domestic chicken, it is able to lay eggs that are about six times the size of a chicken’s egg” see https://en.wikipedia.org/wiki/Kiwi
If you’ve not seen the previous observations, please check them out first at https://coranz.org.nz/do-possums-like-eggs/ and https://coranz.org.nz/do-possums-like-eggs-part-deux/.
To follow the scientific principle, any experiment should be easily repeatable. I am laying out all my steps and observations so anyone can try this in an area populated by possums.
Locally, the possum population is not controlled other than by road-kill, natural attrition and me getting annoyed and culling a few of the local intrusive ones. They are generally well fed with plenty of edible plant species around that they seem to thrive upon. Naturally inquisitive and generally unafraid of either myself or my dog, they are nonetheless a nuisance most of the time.
OK, last night’s experiment:-
Repeating the previous evening, with a hen’s egg and a dog biscuit, but this time adding Golden Syrup (or Treacle) as an attractant smeared over both biscuit and egg.
Our first visitor arrives at 10:07 pm and immediately starts on the dog biscuit – treacle and all:
A couple of minutes later, the egg is investigated:
Yet 5 minutes later, it’s back to the dog biscuit. Note the egg is unbroken:
It takes about half an hour to consume that dog biscuit:-
A quick sniff of the egg, and then departure:
Just 20 minutes later, our next visitor heads straight for the egg – no biscuit left now:
Spends 3 or 4 minutes seriously investigating the egg:
But soon departs – note the egg is still intact:
Visitor number 3 arrives and departs almost immediately. No interest in the egg whatsoever:
And in what becomes our last visitor for the night at 00:33 am, a quick look-see and then departs.
After all this activity, note the egg survives intact – despite being coated in Golden Syrup. Maybe they don’t like it?
Well, all this activity took place whilst I was asleep, but on inspection in the morning it was good to note that not only had the dog biscuit disappeared (as expected), but all the Golden Syrup had been removed from the egg – presumably by licking.
The egg is contained in a plastic dish, so if the syrup simply ran off the egg, it would be collected in the dish. However the dish was completely clean.
We cannot know whether this is a single possum returning several times, or several individuals at differing times. It’s unsafe to extrapolate whether this behaviour applies to New Zealand’s entire population of possums or just a local few.
Conclusion so far seems pretty inevitable that my local possums like dog biscuits, they also like Golden Syrup. They do not seem at all interested in hen’s eggs.
Fourth and final part here: