Mercy Missions and Flying Doctors

Are Ultralights currently in use by Flying Doctors organizations or
for other Mercy relief missions (i.e., Delivering medicines to remote
locations with limited landing fields)? If so, where (on what
continent) would the largest concentration of these operations be?
Have Ultralights been utilized for aerial observation and
communications in disaster relief, such as after Hurricanes like
Andrew or Katrinia, when the bad wx has moved on and conditions are
once again calm?

Also, in regards to providing "lead" for migratory bird missions, how
many such missions are operating? I've seen two, involving Canadian
Geese and Whooping Cranes. Are there other, similar efforts elsewhere?