Image for Tasmania’s Fox Scat Degradation Study. Eco-disaster fear ...

[REFERENCE: “Eradicate” Issue 4 - WINTER 2011 a newsletter of the Fox Eradication Program DPIPWE Publication]

What’s small, brown and can tell you if a fox was about? The answer is a fox scat (poo)! But the big question for the Fox Eradication Program is how long do scats last in the Tasmanian environment?

Understanding the rate at which fox scats break down is vital for two reasons; first, it helps us to understand the potential time between a fox depositing a scat and it being discovered and, second, it helps establish the optimum lag time between completing a fox baiting and beginning monitoring for surviving foxes.

‘Understanding the rate at which fox scats break down is vital.’

Looking for these answers began in July 2010, with the start of the Scat Degradation Project [refer ‘Eradicate’ Issue 2]. This project aims to determine the time period for which:
1) scats look like scats i.e. people can see them; 2) scats smell like scats i.e. dogs can find them; and, 3) fox DNA persists in scats i.e. DNA confirmation can be obtained.

27 fox scats were placed at each of 9 field sites across Tasmania in winter 2010 (243 fox scats) and again in summer 2010-11 (234 fox scats). Results from the 2010 winter study indicate that no scats remained by Day 91(after 13 weeks).

• Only 13% of scats (32) were recognised by people by day 63 (9 weeks).

• Scat dogs could detect 60% of scats (146) that were at least 13 weeks old, including scats that had been
buried by invertebrates.

• Nearly 100% of scats or scat fragments (nearly all 243 scats) analysed for fox DNA (ranging from Day 1 to Day 91) returned positive results.

Results for the summer study (2010-2011) were more variable but, in general, scats lasted longer with some scats remaining on day 126 (18 weeks).

• 20% of scats (49 scats) were recognised by people by day 91 (13 weeks).

• The ability of dogs to recognize scats was variable but all scats were recognised by one or more dogs up to 63 days (9 weeks).

• The DNA analyses for the summer trails are not yet complete.

These trials indicate that a period of around 60 days (2 months) is required after 1080 baiting before surveys for fox scats should be undertaken. The lag period provides confidence that any scats found are from surviving or re-invading foxes. The results also demonstrate that scats may quickly disappear in the environment through break down or by becoming unrecognisable.

[REFERENCE: “Eradicate” Issue 4 - WINTER 2011 a newsletter of the Fox Eradication Program DPIPWE Publication]

Critique: “The results also demonstrate that scats may quickly disappear in the environment through break down or by becoming unrecognisable.” Quickly disappear? Yet fox scat detection dogs could find 60% of scats that were at least 13 weeks in the environment, including scats that had been buried by invertebrates. And “nearly 100% of scats or scat fragments analysed for fox DNA (ranging from Day 1 to Day 91) returned positive results”.

So two months after a fox baiting sortie, how can the Fox Program staff tell whether a scat they find by follow up monitoring was from a fox that was killed 2 months earlier by a 1080 poison and a scat from a “surviving or re-invading fox”?

And after 3 months if detector dogs could find 60% of fox scats and they would still have identifiable DNA, we should much more fox shit if there are any fox scat crappers (i.e. live foxes) out there at all.

So why has the program been so remarkably unsuccessful at finding more than one fox poo in one location or more than one poo from the same fox ?  Even a constipated fox would be more regular than 60 days between shits!

I wonder who provided the scientific oversight of this official Fox Eradication Program [DPIPWE] article. Was it the same person who told Tasmanians attending public meetings that fox scats quickly disappeared in the Tasmanian environment; some were gone in 24 hours? 

• The Examiner: Eco disaster devil fear
BY ROSITA GALLASCH
05 Sep, 2011 12:00 AM

AN ECOLOGICAL catastrophe could occur in Tasmania if fox numbers increase and the devil population continues to be decimated by the facial tumour disease, according to the University of Tasmania’s Menna Jones.

The university’s school of zoology senior research fellow, Dr Jones, said better management systems to guard the devils against the spread of the cancerous tumour needs to be put in place so that their number does not continue to decline and foxes take a foothold in Tasmania.

If devil numbers are retained there would be more of an equilibrium with foxes, which she believes do exist in the state, and less likelihood that native Tasmanian animals will become extinct.

“We’re sitting on the edge of an ecological catastrophe,” Dr Jones said.

“With the devil numbers going down, with the foxes present and we know that feral cats are established here, we could be witness to the extinction of Tasmanian wildlife, much of which disappeared from the mainland 100 years ago.”

Dr Jones said medium-sized animals like the Tasmanian pademelon, bettong, eastern barred bandicoot, eastern quoll, potoroo and native hen could disappear if more is not done to ensure foxes and feral cats are eradicated.

She said 10 years ago when they were conducting research on the Freycinet Peninsula they would have caught 150 devils, today they would be lucky to find 10; with 50 per cent of those with the devil facial tumour disease.

Dr Jones said the East Coast had seen about a 95 per cent decline in devil numbers, while the North-West has also seen a decline.

She called on people not to be sceptics on the issue of whether foxes existed in the state but to volunteer in devil research work, support the Save the Tasmanian Devil program and also lobby for cat control legislation.

Dr Jones is part of a team of five that is one of three finalists in the 2011 Sherman Eureka Prize for Environmental Research.

The prestigious science prize will be announced tomorrow night in Sydney.

Examiner HERE