Tracking The Platypus: A Novel Approach For Wildlife Conservation
What is “normal”? When it comes to wildlife, learning which animals lived where and when can be very difficult, and systematic monitoring of wild animal populations is a recent phenomenon. Population shifts and extinctions are a long-term process, but scientists have only been gathering data in a rigorous way since the 1970s. So, what seems normal for this generation might be a shocking change to a time traveler from three generations ago. To correct our faulty perceptions, researchers now combine historical data with contemporary surveys to detect wildlife population changes. Recently, this novel technique allowed researchers to gauge the range and population health of the platypus, an iconic Australian species.
Platypuses live in and around the creeks and rivers of eastern Australia, but since they are nocturnal, their exact range and population have remained somewhat of a mystery. The first formal survey wasn’t even done until 1970. To determine the range and population trajectories for the platypus, the researchers in this study compiled information from a variety of sources: digitized newspaper records, natural history and explorer journals, and fur trade and museum records from 1760 to 2018 provided source data. Details including the date of an observation, location, activity (e.g. sighting), and number of platypuses were assembled into a data set. Mapping software plotted each sighting along with the time the mammal was last seen.
The final map shows that historically, platypus populations stretched across an area greater than 832,000 square kilometers (321,600 square miles), but from 2009-18, 41.4% of that range showed no record of platypus presence. Even where platypuses still live today, evidence points to a sharp decline in their numbers. Platypuses were highly abundant until the 1890s. Unfortunately, residents began to view them as destructive and to believe they harmed fish stocks. As a result, platypuses were often shot on sight. Large numbers were also killed for their fur, and skins were common in the Sydney market in the late 19th century. While the fur trade was outlawed in 1912, hunting continued. It wasn’t until 1952 that Australia granted nationwide protection to the species.
Platypus numbers never recovered, probably because of the continued volume of hunting. In 2016, the Australian government listed them as near threatened. Today, we find them in a fraction of the area that they once occupied. The combination of a slow reproductive rate and destruction of their habitat means that platypus recovery is anything but assured.
While there may be few animal advocates whose focus is the platypus, this study offers a broader lesson in species conservation. What now seems “normal” in terms of an animal’s abundance may be anything but. Depending on the species, wildlife range and population studies may have captured data for only about 50 years now, a relatively brief period in ecological terms. Studies that use other sources of historical information can provide data for a much longer time horizon, and give a much richer picture of a species’ natural history. This, in turn, will better inform efforts towards the conservation of wildlife of all kinds.