Nine birds, including an endangered swift parrot, had their heads smashed in or ripped off and more than 60 animals were missing on Saturday after vandals went on the rampage at an Australian zoo.
Tasmania Zoo owner Dick Warren said he found the mutilated animals when he opened up on Friday morning, finding "door, after door, after door open and all the locks had been cut, with birds missing and birds dead".
"Either they have just caught them and banged their heads or pulled their heads off, it's a pretty sick thing to see," Warren told ABC Television.
"It's heartbreaking to see them. How could people do this sort of thing? It hits you so hard."
Police said "a number of animals escaped their enclosures, with most being recaptured", adding that two chainsaws were also stolen from the zoo complex.