Their antlers seem to have grown longer in recent years, and the explanation could be the favourable Victorian conditions in which the animals live.

The antler observation was put to members of the Victorian Parliament on Monday, during a parliamentary committee hearing examining the control of invasive animals on Crown land.

Simon Toop, from Victoria's Game Management Authority, told the hearing that the feedback on antler length was anecdotal.

"It hasn't been tested, but one thing we're noticing as an index of condition for deer, particularly Sambar, is their antler size. And once upon a time it was unheard of, or very rare, that you'd see a Sambar deer achieving a greater than 30 inch long antler set.

"We're seeing animals pushing into the high 30s. And what they do in a physiological sense is they divert all their energy into body condition, and then antlers come last. So if we're seeing these animals with these huge antler sets - it means that conditions must be pretty good for these animals," he said.

Sambar deer stag at Yellingbo Nature Conservation Reserve. Photo: Greg Young

Mr Toop also told the hearing that Game Management Authority staff believed that Victoria's deer population was rising. Fallow deer, for example, were an emerging problem in the state's north-west, he said.

"Without having the data to support it, but certainly from strong anecdotal evidence - it's clear that deer populations are expanding their range and increasing their density. I don't think there's any question about that," he said.

The committee heard that in 2001 Victoria had 7500 licensed deer hunters. "We now have over 32,000 and they're harvesting up to 70,000 deer a year. And it appears that their populations are continuing to expand and increase in density," Mr Toop said.

Fallow deer buck with healthy antlers at Yellingbo Nature Conservation Reserve. Photo: Greg Young

The committee also learned a bit about deer migration habits. Mr Toop said deer were crossing both the South Australian and New South Wales borders into Victoria. But the traffic was not one way.

Andrew Cox, from the Invasive Species Council, said it was concerning that Sambar Deer had recently been observed in Wilsons Promontory for the first time.

"Sambar deer are widespread throughout Victoria. There are probably hundreds of thousands of Sambar Deer (in Victoria), but possibly more, because there's no reliable count," he said.

Mr Cox also said "it would be good if aerial shooting for deer would be approved in Victoria".

Barry Howlett, executive officer of the Australian Deer Association, said more areas of public land in Victoria should be made available for licensed deer hunters.

"Wild deer populations and distribution in Victoria have increased markedly since the late 1990s. There is a need now, more than ever, for well-considered, strategic management," he said.

And he said deer should be left as "game animals" and not be re-classified as pests. "A shift to pest status would disenfranchise Victoria's hunting community and undermine the game licensing system," he said.