The COVID-19 pandemic is causing temporary layoffs at the Brookfield Zoo.

The Chicago Zoological Society announced Sunday that nearly a third of zoo staff has been placed on unpaid leave. The workers will keep their benefits.

Critical staff, including animal caretakers, are still at work.

The Chicago Zoological Society, which manages the zoo, said since the facility's closure on March 19, hardly any revenue has been made.

They are asking for donations, and for people to purchase memberships now, for future visits.

"This is a very challenging and difficult situation, and the Society hopes it will be resolved soon," officials said.