they are only vagrant to Borneo, so its still not really an appropriate species for a Borneo exhibit (would be like putting an American robin in an English Manor exhibit because they're occasional vagrants to the UK)
I'll admit to not having realised they were as rare as all that - but bear in mind this aviary also includes Madagascar Teal, Bali Starling, Demoiselle Crane...
the furthest west they breed is Sulawesi, with only occasional vagrants reaching northern Borneo, Java and Bali. Within their range they are most common in Australia and NZ. In fact the very first bird I saw this year was a little pied cormorant flying over my house as I stepped out the front door on 1st January!
