When the weather turns cold, windy and snowy, nobody wants to work outside.

Including, as it turns out, car burglars.

Portland police say they’ve seen an increase in the number of car break-ins reported by people who have left their cars in parking garages, usually overnight, in response to weather-related street parking bans.

“It’s pretty much an opportunity to have many, many cars together due to parking bans and inclement weather,” said Detective Sgt. Kevin Cashman. “The last 10 days or so, there seems to be an increase at those locations and we’re putting that out to our patrol units to hit those areas even more when they’re not tied up on other calls.”

The city has seen 37 car burglaries in January, close to the 39 that were reported during that period last year, he said. There were about 460 car burglaries in total reported in 2014.

Police believe, however, that many car burglaries are not reported to authorities, sometimes because nothing of significant value was taken. Sometimes owners will discover their car was entered only because it smells like cigarettes, or they see wet spots on the upholstery where someone with wet boots climbed in, or find the glove box rummaged, Cashman said.

Car burglars will typically walk through a parking area or along a residential street where many cars are parked, trying door handles and looking through windows for valuables left in sight. They use flashlights to look for anything that may hint at valuables inside, such as wires that would connect to a GPS or other electronics, or even spare change in a cup holder.

“You may not think your smelly gym clothes in a backpack are valuable, but they don’t know that and are willing to smash the window and take the risk,” Cashman said.

The recent parking garage car burglaries, which have occurred in several garages in the city, have included cars that were left unlocked and cars whose windows were broken to get in, he said.

Cashman said car burglars are opportunists. “If they see something they suspect can score them some quick money on the street, they’re willing to take their chance,” he said. They want to get in and out quickly, he said, so smashing a window is more efficient than prying open a door or using a tool to unlock it.

The spate of car burglaries received more attention recently after a turtle and rabbit, stuffed and mounted in Plexiglas boxes, and a fox pelt were stolen from beneath a blanket in the back seat of a pickup truck that was parked at the garage at 25 Pearl St. The items were exhibits used in a Maine Audubon educational program.

The unusual items were stolen sometime between 1 p.m. Sunday and 8 a.m. Monday. Maine Audubon officials said the items would cost them hundreds of dollars to replace but would not fetch much on the black market.

“We’ve put information out to a majority of the secondhand dealers. Someone may try to sell the items,” Cashman said.

He advised people to record the serial number of all their electronics so police can connect them to a specific crime and possibly to a suspect. Snapping a cellphone picture of the serial number and sending it to a home computer is an easy technique for recording.

Car burglaries can be difficult to solve, however, because there is often a lag between the crime and the time it’s reported, and there are seldom witnesses.

In some cases, evidence technicians will try to lift fingerprints or get a sample of DNA that can lead to a suspect. If a suspect is arrested, the evidence can tie him to other crimes.

Car burglaries tend to come in spurts, and usually are the work of one or two people. Police advise drivers to lock their cars and not leave anything that looks valuable within sight. People should not assume that hiding an item under a blanket will be effective, especially if a thief is monitoring a parking area.