Mayhem for Marsupials: How Kangaroo Capabilities Are Being Impacted Down Under

Contributed by Marielle Grenade-Willis

A new documentary, Kangaroo, is illuminating a dark side to Australia’s relationship with one of its most iconic animals. According to an Alternet article and an interview with the filmmakers on Marc Bekoff’s Animal Emotions blog, the creators are exposing a phenomenon that has existed since European colonists came to the outback more than 250 years ago. Many Australians see these magnificent marsupials as pests and are unaware that millions are killed for various purposes such as “pet food, gourmet meats and leather.”

Endemic to Australia, kangaroos possess an awesome array of capabilities. According to Live Science magazine, kangaroos are the only species to use locomotion as their principal means of transportation with a cruising speed of up to 20 mph, females have special mammalian gland-filled pouches in which they raise their young until they are old to thrive on their own, and regurgitate their food before chewing it again like cows do.

A study published this month in Animal Behavior examined the foraging and predator awareness habits of the eastern grey kangaroo to understand whether these behavioral patterns were affected seasonally.

“Kangaroos formed larger groups on richer (greener, more abundant) grass, and both antipredator and exclusive vigilance decreased while feeding rate increased when group size increased. Food characteristics appeared to play a key role in kangaroos’ adjustments to vigilance, as individuals decreased their antipredator vigilance when biomass increased and their exclusive vigilance when vegetation greenness increased. As food characteristics shaped group size and group size affected both vigilance and feeding rate, our results suggest that the driving force shaping variation in the investment in vigilance and feeding rate through the year was the seasonal variation in food characteristics.”

As we can discern from this study, available vegetation and its characteristics were the underlying factors affecting kangaroo behavior. Films like Kangaroo expose the misguided bias against these creatures by farmers, livestock ranchers, and the general public when in actuality, landscapes are being degraded by an overabundance of livestock, not the other way around.