A second batch of birds that have recovered after getting covered in a mysterious substance will be released back into San Francisco Bay Area’s shorelines.
The International Bird Rescue will release 20 to 30 rehabilitated birds at Middle Harbor Shoreline Park Wednesday morning.
About 170 birds died after getting covered in the odorless substance which sapped the animal’s ability to insulate themselves against the cold.
State investigators haven’t yet determined what was in the gray gunk that looked and felt like rubber cement or the origin of the substance.
Eighty-one birds have previously been released in the Bay Area.
Another 323 live birds have been taken to the International Bird Rescue to be cleaned since mid-January when the substance first showed up on San Francisco Bay Area shorelines.
No new goo-covered birds have been found since Jan. 22.