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| I recently found this black rat living in a neglected corner of our garden. |
What if it were possible to deter unwanted rats and mice
using just a scent? Not only would this reduce the deaths of rodents, it may
also save the lives of native rats and mice, and reduce the number of
accidental poisonings of dogs, cats and other animals with rodenticides.
Miguel Bedoya-Perez is a postdoctoral research associate
in behavioural and chemical ecology. In a collaborative project between the
School of Psychology and the School of Life and Environmental Sciences, at the
University of Sydney, he is exploring the chemical, biological and evolutionary
aspect of anti-predator behaviour in introduced and native rodents, in response
to predator odours, working under the direction of Professor Iain McGregor.
Dr Bedoya-Perez took some time out of his day to answer
our questions.
What’s
your day job?
I am postdoctoral research associate in behavioural and
chemical ecology at the University of Sydney. My current research focuses in
the anti-predator behaviour rodents show when presented with the smell of
predators, in particular cats.
What
is the aim of your project?
The aim of this project is to isolate, identify and
potentially synthesize the molecule, or molecules, in cats’ smell that scare
rats, as a non-lethal alternative to poisoned baits for the management of
rodents.
Why
is there a need for more humane pest control?
Several species of rodents are a recognised world-wide as
pests that destroy crops, spread disease and cause enormous damage to
infrastructure. It is estimated that 280 million undernourished people
worldwide could significantly benefit by reducing the losses in harvest due to
rodents. However, these species are also known to develop resistance to many
first, second and third generation poisons, making the development of
alternative methods of control crucial. In Australia, as well as in other parts
of the world, pest rodents can either share their habitat with other native
species, or be themselves native species with population explosions caused by
particular environmental conditions. Poisons and traps are not target specific,
and have the potential to impact these other, sometimes vulnerable,
populations. By tapping in the intrinsic fear rodents show for predators, we
have the potential to develop a method of control that would be specific for
rodents and at the same time non-lethal, reducing the impacts in other species.
But also, because this response is evolutionarily stable, shown by laboratory
rats that have been bred in captivity for generations and have never being in
contact with any predators, there is little chance of development of
resistance.
In
a nutshell, how do scientists capture and reproduce a smell?
The process of capturing and reproducing the smell is
somewhat complicated. But it basically involves acquiring sources of the smell,
like fur, or collars, and using chemical procedures to obtain an extract,
something no different to getting powdered instant coffee from brewed coffee
beans. This extract can then be separated into its individual chemical
components and screened to determine which of those components are responsible
for inducing the fear response in rats. Once the individual chemical or
chemicals are identified, chemists can, depending on the nature of the
molecules, replicate the molecule in the lab.
What
is the outcome of the research?
The method to use the smell will depend largely on the
nature of the chemical and the management target. We need to first understand
how stable the molecule is, its shelf life and the best ways for application. A
stable long-lived molecule could potentially be added to materials, like the
plastic covering of electrical cables or paint use in grain silos. But if the
molecule is less stable and short lived, a regularly applied spray or diffuser
may prove to be more effective.
What
is the most interesting thing you’ve learned about cat fur so far?
I would say, probably the level temporal and individual
variability of the fear-inducing odour in cats. Not all cats are scary, and
this has nothing to do with breed, sex, age or even environment. We have cats
that live in the same house, and are fed the same food, and one cat’s scent is
scary while the other’s is not. We also found that some cats are not scary some
times of the year, but scary at other times. We have a more questions than
answers on why this could be, but we think this may be due to the seasonal
shedding of coats from winter to summer, and also the process of domestication of cats.
How
can people help with your project?
We are very thankful of all the help that we have
received so far from vet clinics, pet groomers and cat owners giving us fur.
The best way you can help is, if you have a cat, brush it regularly and keep as
much fur in as possible in a plastic bag and post it to me within two weeks of
collecting it. We are always looking for fur. If you want to offer extra help,
add details to the fur sample (cat age, sex, breed, is it desexed or not, is it
an indoor or outdoor cat, date of collection, etc.) try to collect all the fur
per sample within a day or two, and finally, the more samples we get from the
same cat several times over the year, the better.
Thanks
Dr Bedoya-Perez for your time. You can follow Dr Bedoya-Perez on twitter @MA_BEDOYAPEREZ,
or to donate cat fur, contact him via email at Miguel.bedoyaperez[AT]sydney.edu.au
