A West Australian farmer who collects rainfall data for the Bureau of Meteorology (BOM) suspects his precipitation is not just falling from the sky, with a fox making regular contributions to his rain gauge.

Tom Murray, from Dalyup near Esperance on WA's south-east coast, has been collecting rainfall readings for the bureau for about 40 years.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 8 minutes 28 seconds 8 m Listen as Tom Murray and Tara De Landgrafft investigate the case of the cheeky fox and the low-lying rain gauge ( ABC Rural; Tara De Landgrafft ) Download 3.9 MB

In the past six weeks though, the dry winter weather led him to become suspicious of a small amount of 'rainfall' that was being recorded.

"I went out to check the rain because we record for the Bureau of Meteorology and, about six weeks ago, there was about 0.4mm in it," he said.

"And I didn't think we'd had quite that much, so I looked a little bit closer and it actually had a little bit of colour in it, so I got a bit suspicious.

"My winemaking background came to the fore and I thought I needed to apply the sniff test and it was decidedly foxy."

Mr Murray said the fox had made several contributions since, but he had never caught him in the act. And so Operation Fox Cam was born.

Dalyup farmer Tom Murray checks his rain gauge to see if the local fox has made a contribution. ( ABC Rural: Tara De Landgrafft )

A cunning plan

In a bid to discover if it was indeed a fox making a contribution to the Murrays' BOM rain gauge, ABC Rural borrowed a motion-activated night vision camera to try and catch the cunning fox out.

Mr Murray banged a new star picket into the ground about 10 metres from the gauge and used wire to attach the camera to the post.

The camera was left out for two consecutive nights and the footage was reviewed each day, but despite the best efforts, the fox remained elusive.

"They're noted for their cunning aren't they?" Mr Murray quipped after reviewing the footage on day one.

"I reckon he did it from a distance.

"I don't know how he did it, but something certainly made a contribution, only a small one, but we certainly couldn't spot him."

Joking aside, Mr Murray was unsure what to do next, considering the fox is still making the odd contribution to his rain gauge.

"I don't know, I'm wondering if the bureau may put an adjustment figure in for my particular rain gauge or we just hope that we get enough rain shortly to dilute it," he said.

Farmers' tale may not apply

An old farmers' tale that explains possible rainfall abnormalities in an otherwise dry set of conditions is the story of the long-legged dog and the low-lying rain gauge.

But despite Mr Murray's rain gauge being just 30cm off the ground, as per BoM guidelines, he has ruled out his dog Buster.

"I usually make sure I get to the gauge before him," he said.

The camera is set up, pointed at the BOM rain gauge on Mr Murray's Dalyup property. ( ABC Rural: Tara De Landgrafft )

"He refuses to pee in his pen so he's usually got a fair bit stored up, so I'm very conscious of that because he has a lot of potential.

"But fox pee is very distinctive in the aromatic area."

Mr Murray said the rain gauge conformed to all the required standards, and was "not the usual plastic fantastic that most people have stuck on a post somewhere convenient".

He thinks the fox may be deliberately aiming for the rainfall measuring device.

"He does tend to wind the dog up," he said.

"He goes past the dog's pen each night with his tail high in the air and gives him the bird or something because my dog hates foxes."

Mr Murray resets the rain gauge for night two of surveillance. ( ABC Rural: Tara De Landgrafft )

'Yellow rain' not uncommon, bureau says

Neil Bennett, from the BOM in Western Australia, said "yellow rain" was not uncommon, but it was the first time he had heard of a contribution from a fox.

"I haven't heard of a fox, no," he laughed.

"The mysteries of yellow rain are fairly common, especially on clear days when you know there is no cloud out there and suddenly the rain gauge is reporting something, your suspicions are raised.

"Dogs I've known about but foxes, that's a new one."

Mr Bennett said with hundreds of rain gauges on farms around the nation, the reports were all quality controlled when they came in.

"It's not like we put them in completely unaltered," he said.

"We're looking at them to make sure they do meet the quality control, and obviously if there are no rain reports in surrounding gauges and you know the day was clear and sunny, then your suspicions are raised when it's coming in with 20 millimetres or something like that.

"But yeah, yellow rain is a fairly common occurrence I'm afraid."