Karen Yu '15, Sophie Bernstein (Bucknell '16), Kaitlin Creamer (Kenyon '16)
Whistling birds and blaring cicadas are natural alarm clocks that push us out of bed for our morning run. We step out the door, and our feet stomp through the glistening dew. Pounding our way towards the crystal-blue water of Lake Eacham, we turn a corner only to stumble upon a brush turkey with raven-black feathers, a bright red head and a yellow wattle. The more corners we turn, the deeper we get into the rainforest, and the more animals we encounter. We halt as small brown rodents scurry by our feet, across the forest floor. They are musky rat-kangaroos. These seemingly insignificant rodent-like creatures play an important role in the rainforest. We, three SIT study abroad students interested in musky rat-kangaroos, not only use Lake Eacham as part of a unique study but also as a place for our morning runs. For the past three semesters, students like us have been recording musky rat-kangaroo sightings at four locations, including Lake Eacham. This is the only study of its kind in the World Heritage Wet Tropics region of North Queensland, Australia.
The musky rat-kangaroo is a marsupial — a pouched animal — found only in the northeastern rainforests of Australia. Luckily for us, they are diurnal, which means they can be easily spotted during the day. They eat fruits and insects. Sometimes they bury their food, which spreads fruit tree seeds throughout the rainforest. The population of these important seed dispersers also depends on the abundance of fruit. According to musky rat-kangaroo expert Andrew Dennis, “Variation in the availability of fruits correlates to changes in the reproductive output of both male and female musky rat-kangaroos.” Their surrounding environment shapes the biology of the musky rat-kangaroo.
The musky rat-kangaroo gives researchers a glimpse into the environmental impacts of fragmentation. Habitat fragmentation occurs when continuous existing landscapes are broken up. We sought to understand the differences in musky rat-kangaroo abundance and distribution in both fragmented and continuous sites. The study was accomplished by surveying each location for two hours. The four sites that SIT students look at are Lake Eacham, Lake Barrine, Gadgarra and Gillies’s Range. Compared to the 2014 wet and dry seasons, all SIT students saw fewer musky rat-kangaroos this wet season. Most groups this year did not see much fruit on the ground, which could explain why we saw fewer musky rat-kangaroos. Our observations support the correlation found by Andrew Dennis. We also noticed that there were higher numbers of musky rat-kangaroos at the fragment sites—Lake Eacham and Lake Barrine. Musky rat-kangaroos prefer to reside near water, which could explain why there were higher numbers at the two lake fragment sites than the continuous sites without water.
The fragments in our study may not be representative of other fragments in the Wet Tropics. Both of our fragment sites, Lake Eacham and Lake Barrine, are located around a large body of water, which may not exist at other fragments. Even though musky rat-kangaroos thrive here, we speculate that populations could be in more dire shape in fragments without water nearby. Habitat fragmentation could make these musky rat-kangaroos absent from our daily runs in the rainforest.
Combating habitat fragmentation is important because it protects species like the musky rat-kangaroo that help build our future rainforest. Fragmentation ultimately causes the loss of a unique and diverse habitat. This is alarming because, although the Wet Tropics cover only a small portion of Australia, it has been estimated to be home to over 1,000 animal and plant species. Some species, like the musky rat-kangaroo, are found nowhere else on Earth.
With learning comes appreciation. As students on the SIT World Learning program, we have seen for ourselves the beauty and importance of rainforests. Without being introduced to the musky rat-kangaroo, we would not have had such a strong understanding of how one species can impact the Wet Tropics of Australia. Our future morning rainforest runs will include a new perspective of the furry brown mammal hunting for its juicy fruits among our forward-moving feet.