ahhh .. possess the keeness and acute sensitivity of an animal??
I think they probably sensed the coming of ill .. long before it became ill ..
like horses and birds can sense the coming of a change in the weather .. or a storm .. you know that kind of high level 'pin point' acuity found in many of the animal world ..
yeah maybe it would have been easy to
'see ill of the sunbane' if your an outsider looking in .. but the inhabitants of the Land were 'a significant number'

.. and they didnt percieve its
ill .. presumably they were given time to be conditioned to its presence ..
The Raynhin and the Ramen .. acutely perceived the ill <like sensing some ill omen in the air> .. that was coming .. but not there yet I imagine .. and expeditously got as far away as they could from that perceived ill ..