This winter's heavy snowfall in New Brunswick could cause a 25 to 30 per cent decline in the deer population, says a biologist.

"A deer's legs are only two feet long, and when you get snow over that it causes a lot of problems for the deer," said Rod Cumberland, New Brunswick's chief deer biologist.

Deer are starting to deplete their winter fat reserves, but the continued heavy snow cover is making it hard for them to find more food, Cumberland said.

"When their systems are starting to kick into gear and they need that extra energy, that can spell a lot of trouble for deer in this neck of the woods."

The crusty snow conditions in much of the province also cause deer to become stuck in the deep snow, making them easy prey for predators, Cumberland said.

"It's a little bit early to tell, but … if things keep tracking as badly as it looks right now we could have 25 to 30 per cent of the herd lost. It's a huge number."

Any loss, though, needs to be measured against an increase in deer numbers following the low snow levels over the past three winters in New Brunswick, Cumberland said.