Amazon bolstered the number of robots operating in its warehouses by about 50 percent over the past 12-month period, according to newly released data.
The Seattle Times reported that the e-retailer deployed about 45,000 robots in its distribution centers during the 2016 holiday season. That's up from some 30,000 robots in the previous season and from 15,000 in 2014.
Amazon uses the squat, square-shaped orange robots to maneuver around its stockpiles, then slide underneath shelves to pick up and carry as much as 750 pounds of merchandise.
The system relies on a central computer and navigation points in warehouse floors, as well as bar codes on the products themselves.
The robots helped curb the time from order to shipment in Amazon warehouses by 80 percent and improved warehouse capacity by 50 percent. Reports last year said they also helped cut operating expenses by 20 percent — which meant that Amazon's purchase of robot maker Kiva in 2012 is effectively paying for itself.
Kiva was rebranded as Amazon Robotics in 2014.
Amazon's rapidly growing distribution operations are also hiring more human workers, but reports suggested that automation is keeping hiring in the warehouse sector down despite increased shipping demands from online shoppers.