These giant, green camouflage experts are threatened by predators, invasive species, human encroachment, and a debilitating illness colloquially called crusty bum disease (exudative cloacitis). Crusty bum disease causes inflammation of the lower digestive and reproductive tracts. Once widespread across New Zealand, kākāpō are large flightless parrots that can weigh as much as 8.8 pounds. With the risk of antibiotic resistance, conservationists need to monitor what is going on in their gut bacteria. However, these bacteria may have sprung up in their guts naturally, so cautious treatments with antibiotics can continue when treating crusty bum disease or other ailments.