CROCODILE tour guide Mark Norman wants people using the Proserpine River to be aware that hatchlings are now emerging and wherever there are baby crocs, their much larger mothers are sure to be about.

Mr Norman said the first of the year's hatchlings started emerging about two weeks ago with about 35 babies in the first batch.

"And over the last five days we've had about four nests hatch - and in one nest that hatched about two days ago we had a record count of over 70 hatchlings," he said.

Mr Norman, who has been a tour guide on the Proserpine River for about 12 years, said while most of the resident female crocs were about 2.5 metres long averaging nests of about 30-50 eggs with a hatching rate of 15-25, this particularly large brood belonged to a three-metre female.

"And that's a large female," he said.

"Anybody on the river needs to be very aware that the mother crocodile is present at the site where the hatchlings are so it's extremely dangerous to approach them. In fact, she will most likely be under the water right in front of them."

On average, less than one percent of hatchlings on the river will make it to adulthood, with their survival threatened by predators, other crocodiles and even man.

Mr Norman said one of this year's first nests had over 30 hatchlings initially but just one day later only two were left.

"To have a reduction of that many in a day is very unusual so the possibility of human intervention is there," he said.

"I've heard of people catching them over the years although nothing's been proved. Anybody using the river just needs to be aware they're a protected species."

A spokesperson for the Department of Environment and Heritage Protection said there was no evidence human intervention was responsible for this most recent loss, with the likely scenario that the hatchlings were either eaten or had swum away.

Hatchlings will continue to emerge on the river from now until the end of next month.