Parks and Wildlife rangers say they expect increasing numbers of saltwater crocodiles to be spotted around Darwin waterways in coming months.

Northern Territory Parks and Wildlife ranger Robert Risk says a four-metre saltie was pulled from Darwin Harbour and a three-metre croc was harpooned near the Larrakeyah naval base over the last few days.

He says the crocs are on the move because of the humid weather and are feeling frisky in breeding season.

"They are a bit more active, looking for a feed and stuff," he said.

"We are certainly getting few reports of crocs moving around the beaches.

"It's a good reminder to be wary."

Last year, 215 crocodiles were captured in Darwin Harbour and relocated, including a massive 4.2m male.

A record 314 salties were removed from Top End waters in 2012.