Biggest challenge for self-driving cars in Boston? Sea gulls.

nuTonomy’s driverless car has concluded its first 100-mile test in the Flynn industrial park in South Boston. Jessica Rinaldi/Globe Staff

The first month of testing of its self-driving car by nuTonomy Inc. has gone largely according to plan, the vehicle successfully navigating its way around the Raymond L. Flynn Marine Industrial Park in South Boston.

But the car has struggled to recognize a common fixture around the waterfront: flocks of sea gulls that congregate on the roads during winter.

“One bird is often small enough that the car assumes it can be ignored. But when you have a flock of birds together, it looks like a big object, so we’ve had to train the car to recognize the birds,” nuTonomy chief executive Karl Iagnemma said. “It wasn’t something really that we’ve seen before.”

The vehicle, which has a human in the driver seat to take control as needed, reacts to the flocks the same way a human might: it slows down while approaching the birds until they fly away, and then resumes its normal way. It generally slows for any unrecognized object.

Iagnemma said it’s important to teach the car’s software to recognize the birds for what they are, to “give the vehicle a better capability to predict what’s going to happen next.” The company teaches the vehicle to recognize new objects by continually feeding imagery of the object into an algorithm. Other examples include MBTA buses and recumbent cycles, which riders pedal while seated in a reclined position.

Prior to taking to the road in Boston, nuTonomy had conducted driverless car tests in Singapore. The sea gulls, Iagnemma said, are an example of how new settings bring new challenges.

“You end up having to adapt the system to the local conditions,” he said. ”It’s a good example of a unique aspect of driving in Boston. Is it a fundamental change to our approach? Absolutely not. Is it something that takes a little time to adjust our software to? Yes.”

nuTonomy’s car has traveled 100 miles in the industrial park so far, all done in daylight and dry weather.

That marks the first major benchmark for the testing, and the company is now waiting on Boston officials to allow it to begin the next stage, which involves testing in the same location at night and in rain. However, it’s not clear when the city will give the go-ahead.

“The City is pleased that the weather cooperated with us in January to allow nuTonomy to achieve the initial milestone set out in their testing plan, and looks forward to continuing to work with nuTonomy,” Audrey Coulter, a spokeswoman for Mayor Martin Walsh, said in a statement.

If nuTonomy successfully concludes its next 100-mile testing round in the industrial park, the company will then try to try the car out in another part of the city.

nuTonomy has taken warmly to the Seaport District. It recently announced plans to move its offices from Cambridge to the Seaport’s Innovation and Design Building, within steps of the testing area.

Another startup making driverless technology, Optimus Ride, which had also been based in Cambridge, is making a similar move. It recently leased 20,000 square feet of space near nuTonomy’s space, at the end of Black Falcon Avenue.

Optimus Ride, which raised more than $5 million in seed funding last year, has said little about what, exactly, it is working on. But co-founder Sertac Karaman said the new location will be used for both offices and as an indoor testing area.