calicivirus, 1080 poison, agricultural chemicals, and habitat fragmentation combined with a retrovirus were other proposed causes. environmental toxins had also been suspected. in march 2006 a devil escaped from a park into an area infected with dftd. she was recaptured with bite marks on her face, and returned to live with the other devils in the park. she wounded a male and by october both devils had dftd, which was subsequently spread to two others (an incident that in retrospect would be understood in the context of the allograft theory of transmission).