What can I tell you about platypus? Well, I can tell you what Biologist Geoff Williams told me (and around 50 others) at the Yea: Platypus talk and training workshop. The platypus has entered “Near Threatened” territory. Geoff was representing the Australian Platypus Conservancy (APC) – who are working with the Goulburn Broken Catchment Management Authority (GB CMA) – to tell us why, how things stand and what we can do to help. GB CMA’s Project Officer Sue Kosch says, “It is vital that we get a good idea of how this special species is fairing.”
Platypus are unique to Australia. They can be found along the east coast from Tasmania to Queensland, but rarely as far west as South Australia. Platypus are a monotreme, a mammal that lays soft, leathery eggs. Juveniles disperse in autumn and travel long distances. However, a typical home range is 1-7km depending on food supply and water flows. They are commonly found in water from 1-5m deep. They can live up to 20 years. The male has venomous spurs protruding from its back feet. The venom won’t kill you, but can make you pretty sore. It is best to avoid handling these creatures. In the past, they were hunted for their skin.
Platypus have an electrosensitive bill that senses the tiny amounts of electrical energy released when their prey move about. The bill is soft, unlike a duck’s bill. The platypus does not have teeth, so as they shovel along the waterway beds and banks, they do not catch creatures that need to be chewed. Consequently, fish are a rare part of their diet.
Thousands of individuals probably remain, but the population is in decline. Decline is due to erosion, sedimentation, bank compaction and vegetation loss. Also, introduced weeds, loss of natural water flows, alienation of natural flows into artificial channels. Over harvesting of water creates unreliable flows have a deadly impact as well. Feral animals can be a problem. Low water flows expose platypus to predation by foxes and cats.
A key issue is fishing gear, whether carelessly abandoned or deliberately placed. Encounters with irresponsibly left fishing litter such as netting, hooks and lines and/or deliberate use of fish and yabbie traps are usually fatal. (Some good news is that traps and nets have been banned by the Victorian Government from July, 2019.
Monitoring of platypus over the years has been problematic. Live trapping has not proved representative. Camera traps are little use for an animal low in the water. eDNA only gives a present or absent result.
However, SIGHTING REPORTS have proved very valuable for assessing distribution to date. You can check this in the Atlas of Living Australia. Although sightings have not been comprehensive enough for monitoring wider quantitive data so far, it has been noted sighting data correlates well with live trapping data. This suggests a coordinated Citizen Science Monitoring Project has great potential. Hence, promotion of this project by the Australian Platypus Monitoring Network (APMN): http://www.platypusnetwork.org.au
So, what can we citizen scientists do?
- Choose a regular visual survey site from the web site. The ideal is you can get at least a 20-30 metre view along the water.
- Or you can register a new site. If you do, be sure to choose name that is meaningful to others who might want to monitor from it. Smaller waterways and dams can be OK too, but may require up to 30 minutes each monitoring visit.
- Stop at least once per week and scan carefully for 5-10min (if they are there, they will appear).
- Early morning and late afternoon are prime time, but early morning is likely to be best.
- Record positive and negative sightings on the APMN app (Apple or Android). The average ratio of positive to negative sightings is 1 in 10. Some sites do much better, multiple individuals at once may be seen.
- Findings are summarised on the website.
This is what I now know about platypus.
My new question is to Strathbogie Tablelanders. Who on the Tableland is up for it? Polly McQuinns has a platypus population. It is an easy waterway to observe. We could roster the monitoring so that it can be frequent, but no one individual has to take responsibility for the site monitoring all of the time. You can contact me (Sean Mathews, Secretary Strathbogie Landcare) either through this blog or firstname.lastname@example.org