The MacKenzie River, originating in the Grampians and flowing west towards Horsham, supports the last known platypus population in the Wimmera Catchment (although occasional sightings have been reported elsewhere).
Platypuses have significantly declined throughout the catchment due to a combination of severe drought and human impacts (e.g. water diversion, clearing vegetation along waterways, habitat fragmentation).
Accordingly, cesar has been closely monitoring the MacKenzie River platypuses on behalf of the Wimmera Catchment Management Authority (WCMA) since 2008.
The small population has proved remarkably resilient, persisting through the Millennium drought, ongoing removal of water for domestic and agricultural use, and severe flooding in 2011 (see: Impact of severe flooding on platypuses in MacKenzie River).
Recently, WCMA have implemented an environmental flow regime to improve conditions for platypuses and other aquatic fauna and flora in the MacKenzie River.
In early 2014, the platypuses faced yet another challenge – bushfires in the Grampians National Park that severely burnt much of the catchment surrounding the upper MacKenzie River.
Extensive surveys in April 2014 revealed that not only had platypuses survived the immediate impacts of the fires, results were the best that had been recorded for years!
Four platypuses were captured, which may not sound like many but represents the highest abundance recorded in these surveys for nine years.
Particularly exciting for cesar ecologists, WCMA staff and survey volunteers was the presence of two juveniles. This is the first evidence of successful reproduction since 2006.
Although recent results were highly encouraging, it is important to note that the platypus population in the MacKenzie River remains highly vulnerable due to its small size and isolation and longer term impacts of the bushfires are still to be determined.
However, it was fantastic to see the population heading in the right direction and attests to the resilience of this remarkable Australian species.
Spotted a platypus?
Spring is a busy time of year for platypuses…its breeding season!
Platypuses are most active during spring, and males can travel large distances to find female breeding partners. Accordingly, spring is the best time to spot a platypus!
Platypus sightings assist in understanding the distribution and occurrence of this iconic species leading to improved conservation efforts.
Submit your platypus sightings at www.platypusSPOT.org.