CHICAGO—From offering premium pay to hefty signing bonuses or poaching workers from other airlines, American carriers are scrambling to ramp up staffing for the holiday season and prevent disruptions that marred air travel this summer. After reducing headcount by thousands during the depths of the pandemic, the industry is grappling with shortages of pilots, flight attendants, and customer service agents. A Delta Air Lines spokesperson said the company had no furloughs or job losses related to the pandemic. However, the company did have about 18,000 staff departures last year in the form of retirements or voluntary separations. With willing workers in short supply across the United States and companies frantically vying for them, carriers are being forced to spend more to attract talent. “The reality is that the hiring environment has changed as a result of the pandemic,” American Airlines’ chief operating officer, David Seymour, told employees in a memo …