We already know well that rabbits have wreaked havoc on the Australian landscape, eating up our native plants and kicking some of our native mammals out of their homes. And those little holes that they dig all over the place that you might be unlucky enough to roll your ankle in aren’t too good for our environment either! Whilst our bilbies and bettongs dig similar holes, it has been shown they are much more beneficial for the environment.
A study completed at Lorna Glen in central Western Australia used data loggers to record temperature and humidity, amongst other things, in bilby diggings, and in areas that had not been disturbed. The results showed that the microclimate (the climate inside the bilby digging) compared to that in areas of soil that were not disturbed, was not as variable. The difference in humidity levels and temperature during the night and day, was not as great as that in other areas. For a quick over view of the findings, click here.
Arid Recovery has also completed research on the role that bilby digs play in ecosystems, and has some interesting results. The data showed there were higher levels of carbon in bilby digs, compared to those of rabbits. Our native species are helping us try combat global warming! Data about the rate of mulga germination also shows that our native fauna helps out our native flora. Rates of mulga germination are higher inside bilby digs when compared to rabbit digs or undisturbed soil. This could be due to a number of factors, possibly higher levels of nutrients in bilby digs due to exposing the deeper soil which is more fertile than the top soil, or the small hole collecting leaf litter and water, which breaks down to increase soil fertility.
A graph depicting the average percentage of carbon in a bilby dig compared to the soil surface. Graph by Alex James
A graph depicting the average number of mulga seedlings in bilby digs compared to rabbit digs and the surface. Bilby digs have nearly 3 times more seedlings than rabbit digs or on the surface! Graph by Shannon Sparkes
Thanks for some of the research and findings about bilby digs and their roles as environmental engineers must go to a number of students we have hosted over the years.