PHOTO: Regional NSW ecologist Dr Joanne Ocock holding a native wrinkled toadlet species found in the Macquarie Marshes. Image courtesy of Dr Ocock.
By OLIVER BROWN
A WETLAND ecologist working in regional NSW promises recent spikes in the population of insects and frogs in and around the Coonamble area is not the sign of the apocalypse but rather a natural result of a wetter than average summer.
Over the last few months, residents have been surprised to see their homes swarmed by bugs and surrounded by frogs.
National Parks and Wildlife wetland ecologist Dr Joanne Ocock who spends a lot of time in the Macquarie Marshes, said the increase in local populations have likely come about due to the cooler summer evenings the area has experienced over the last couple of years after the break of the drought.
“We’ve now been through about two years of these luscious La Nina conditions which we hadn’t really had over the previous five years,” Dr Ocock said.
“Then we had a lot of extra rain from around October last year – because it came on the catchment where the land was already wet, it resulted in widespread river flows and broader floodplains on the Castlereagh, creeks which haven’t really been flowing in years.
“So when they do that, it means perfect breeding places for a lot of insect species – particularly for aquatic species like mosquitoes and dragonflies.”
When asked why some other insect species which are not aquatic, such as crickets and earwigs, had also increased, Dr Ocock said the flowing rivers and greener conditions also meant there was a wider food source for all sorts of wildlife.
“I was actually out somewhere the other day and thought to myself that there were so many red-rumped parrots around – it’s likely they’re also benefiting from these mild humid conditions as well as the increased presence of insects which support so much life as a food source,” she said.
“The wet conditions also make a perfect habitat for frogs – the (recent) floods created a lot of shallow floodplain waterholes which don’t get fish as quickly but frogs love them because they can lay their eggs and have a better chance of surviving.”
Dr Ockock said while she hadn’t read any scientific studies to actually quantify it, it was likely the higher than average frog population was keeping the insect population from growing even further this season.
“We’ve always talked about the idea that without frogs, we would have way more insects – even the tadpoles hoover up the mosquito larvae before they become mosquitoes and as adults they would likely be eating the crickets,” she said.
According to Dr Ocock, it was likely the most common frog being identified, particularly following wet conditions, was the green tree frog which are often found in toilets, pipes and on windows.
However, she said the weather seen over the last couple of months was also perfect conditions for other species to come out of hiding.
“There would be about 15 different frog species living in and around that Coonamble area and at least five or six of those would only come out after rain because they’re burrowing species,” she said.
“They breed really quickly within about two to three weeks and when it starts to dry out, they go back underground again.
“Ones I think people would definitely be wondering about are the ones with pink racing stripes called a salmon striped frog. I think people would be seeing them in big numbers because they tend to get in people’s pools and can’t get out again.”
One local who has noted the large spike in frogs around her house is Tracy Moody.
“I love it that we have so many new friends in the garden,” Mrs Moody said.
“I’ve saved so many from the pool filter, however the silly buggers continue to get in there.
“We’ve also had a couple of green frogs somehow get into the house and I wake up to a loud screech as the cat is playing with it, so I save them again and then put them back out on the garden.”
While there has been concern surrounding the unfamiliar species and whether they are safe to be around, Dr Ocock said it was important to note they posed no danger other than occasionally being a minor annoyance.
“All the native frogs in Australia are non-toxic so there should be no concerns for dogs to be eating them or anything like that,” she said.
“I urge people to just put them outside and not kill them – I realise they can be a bit of an inconvenience because they can be noisy and leave a bit of a mess on windows or veranda.
“However, in the next two to three months, they’ll have disappeared and we’ll be back to quieter times.
“In the meantime, just think of them as food for something – frogs make excellent snack packs for other species – and something that is trying to enjoy the beautiful country landscape like the rest of us.”