MILWAUKEE (CBS 58) -- Versiti Blood Center is holding a blood drive at the Milwaukee County Zoo through this afternoon, offering incentives to donors during a time when supply is typically low.

The drive started Monday morning, Dec. 29, and runs until 2 p.m. at the Peck Welcome Center. Donors will receive free same-day zoo admission, a ticket for a future visit and a $25 gift card.

Blood supply drops over the holidays due to travel plans, vacations and holiday activities, according to Versiti. Chad Dunning from donor services said the need for blood doesn't stop during the holidays.

"A patient needs a blood transfusion pretty much every two seconds in the United States," Dunning said.

The blood drive continues Tuesday, Dec. 30 from 7 a.m. to 1 p.m.