Packs of Hollywood dinosaurs from “Jurassic Park” are long gone from a remote green valley at Kualoa Ranch. But something new and unusual took over part of the ranch in Kaaawa Valley this week.

It can be hard to spot them in motion. They are small flying machines buzzing around at blurring speeds nearing 100 miles per hour. And they began swarming Tuesday as part of the emerging sport of miniature drone racing.

Close to 200 pilots from about 50 countries are expected to participate in the competition, which runs through Saturday.

Alf Skaar, a 49-year-old Oracle Corp. employee from Norway, took two roughly nine-hour airplane flights to race in a qualifying round of events dubbed the Aloha Cup and held earlier this week.

“I really feel this is amazing,” he said. “It’s the speed. I love the speed.”

Rob Avery, a drone racer from Australia who participates in two or three races a month, said the Windward Oahu location that served as a setting for “Jurassic Park” is an incredible place for an international competition.

“What a place to have a drone race,” he said. “The location is awesome.”

Organized by the nearly 3-year-old, Berkeley, Calif. -based Drone Sports Association, the events at Kualoa Ranch are part of a growing number of drone races including one in New York streamed live online by ESPN3 in August and one in Dubai, United Arab Emirates, that offered $1 million in prize money in March.

August “Jay” Gatchalian Jr., a 30-year-old Ewa Beach resident competing in the Aloha Cup, got involved with racing in March after he bought a recreational drone that quickly became boring to fly. “I wanted something more exciting,” he said. “So I bought a racing drone. It’s addicting.”

Racing drones often are custom-made with basic parts including a carbon fiber frame, four propellers, a battery and a camera. A competitive setup with a flight controller can cost $200 to $500. Each drone typically is about a foot long or smaller.

Pilots control their “quad” copters wearing gogglelike headsets that transmit the view of the onboard camera, conveying a sense that the operators are in the drone. They also get assistance from a navigator called a spotter who watches the drone zip around the course and can tell the pilot about surrounding conditions that can’t be seen in the camera view.

Gilbert Coronado, 20, brought three quads to the Aloha Cup from his home in Austin, Texas, because crashes are common and not all broken parts can be repaired between heats.

In one heat on Tuesday, all five pilots crashed their drones, some with a loud whack into track obstacles.

The track, laid out in what is normally a pasture for grazing cattle, consisted of 13 rings with roughly 7-foot-diameter openings that drones had to fly through, and three H-shaped gates that drones had to loop over. Small colored cones marked the path between obstacles on the ground. Each race was three laps, and the adrenaline could be sensed among pilots as they made sure all their equipment was ready before takeoff.

“Pilots, thumbs up for good video,” an announcer said, readying the first race of the day by checking whether racers could see the camera image from their drones. “Hold them high in the air. Power up. We are good to go. Quads to the line.”

After three beeps and a simulated gunshot, the drones took flight from a table serving as a launchpad. Bzzzzzzzzzzzzzzzzzzzzz …

Danny Chan of Hong Kong placed first, beating opponents from Denver, Las Vegas, Seattle, Texas, Chile and Korea. Chan improved his chances of advancing to the higher-level event, the first World Drone Racing Championships, which started Thursday and promises $100,000 in prize money.

More races in the championship event are scheduled for today and Saturday, and are open to the public at no charge.