Field Report 6: Fitzroy Station Toad Bust 12 th -13 th August 2006

Report by David Woods.

Crew: John Cugley, Donna Cavlovic Chris Shaw Desanka Mijovic, Yo Early and Dave Woods

 

Leaving just before 6.00pm on Saturday evening saw us arriving at our camp on the banks of the Victoria River just after 10.00pm . Our job this weekend was to report back to Lee on numbers of toads in this area. As the Victoria River dissects Fitzroy Station, we would be focusing our search closely around its permanent pools. As time was limited, it was decided to use this trip as a gauge to how much attention this area will require over the coming weeks.

We had a quick break after our long drive and then we checked the local area near the rapids. This was an easy place for Toads to cross the river because it narrows considerably as it cuts through a dolomite rock bar. We checked the Western side of the river; Johno and Donna went downstream to conduct their search whilst I went upstream. We met back at camp after a couple of hours and the news was not good!

We had barely headed 500 metres in each direction and collectively we caught 87 Toads. The sandy riverbanks in this area were leaching out ground water, enough to create perfect habitat for Cane Toads. It was also very apparent that this area provided great daytime shelter for hiding toads, as there was no shortage of rocks, sand and muddy burrows to hide in. As it was now after midnight and we were all pretty tired after our long day and bed was sounding good.

In the Morning our late arrival toad busters, Chris, Desanka and Yo, were keen to get in the action and helped us measure and sex last nights haul. There were 71 males in varying lengths from juveniles around 45mm to mature toads 135mm long Females for the previous night totalled 16 and had a similar size range as male toads found from same area. Also Chris Shaw has donated a pair of Vernier Callipers, which makes measuring super easy and super accurate, Cheers!

On a Toad Bust a couple of weeks ago Chris Shaw found Toads during the day. I was confident of the same success today as we learnt some valuable lessons on that trip to Skull Ck. Johno and Donna took the Quad Bikes downstream following the track but as it has not been graded this year, it was slow going and after a few kilometres they cut back in to the Victoria River .

They checked a few locations for any toads in the banks of the river but none were found. Muddy and sandy banks are ideal but where Johno and Donna were, were rockier in composition. As we are finding the Toads are very specific about where they hold up in dry season conditions.

I had spied a creek on the map that ran into the Victoria River a couple of kilometres upstream from where we camped. Although this creek would not be flowing, a check was required where it entered the river. The Section of river is called Tortoise Reach, which is over10 kilometres in length. The River in this area is mainly steep banked and they rise sharply from the waters edge. The banks that are matted together by roots coming from the dense vegetation that exists around these permanent pools Although there is sand and mud making up these banks, they are heavily compacted and fused with tree roots. Along with steep banks and closed in shady areas, there is a low chance of toads habituating along these sections of river.

What happens where creeks enter these steep banked sections of river? Johno And I took the Bikes through the bush upstream until we intersected the creek. A quick ride up the stream verified it was indeed dry, so we turned the bikes around and followed it downstream until we hit the river. We walked down into the dry creek bed and starting back about 20 metres from the rivers edge the mud underfoot became soft and wet. So we started searching for toads in holes, cracks in the mud and under half buried logs

My first log produced a couple of toads straight away, not good! Johno also found a likely log close by and started to pull one after the other from under it. I walked back up to the bikes and grabbed a garbage bag. By the time I got back to Johno, which was at least a couple minutes, he was still pulling toads from the same log and his other hand was loaded with 20 plus toads I was amazed to see how many toads were jammed into a hole no bigger than a lunch box!

I relieved Johno of his toads and it wasn’t long before we found more jammed into a long crack in the mud, but this time now only a couple of meters from waters edge. We ended up with 52 males and 12 females from this Creek’s mouth. I then found a dead freshwater crocodile still half in the water on the bank of the river. We decided to leave it there and head back to camp. We discussed the crocodile with Chris and Desanka and they agreed that it was likely it died from eating Cane Toads but it would be better if we knew for sure.

As Desanka was a Vet’s Assistant and knew how to perform an autopsy we decided to take her back there to investigate further. Desanka began to dissect the crocodile’s under belly to expose the digestive system and it wasn’t long before the stomach was located and removed from the dead crocodile. Desanka then made an incision into the stomach wall and sure enough, revealed two Toads. So it was now highly likely that it died from ingesting these toads found in the dead crocs stomach.

The day was disappearing quickly so it was time to pack up and head home to Kununurra. In total our Toad count was 151 and 64 of them were caught during the day. Thanks again to the dedicated crew whom make these missions possible. Every trip brings us new information, which will strengthen our fight against the Dreaded Cane Toads

Foot note: The permanent pools on the Vic River that are steep banked and heavily vegetated would be best accessed via a small boat. As this would allow us to scan each side of each pool much more efficiently than by doing it on the shore by foot.