"There must be areas in which native catfish are hungry and in proximity to birds. Maybe it occurs there too."
Its the combination of birds being available and regular food not being available and then one has to be successful enough at it to survive. Catfish are pretty opportunistic feeders, which is perhaps why they would consider birds to be food if they were otherwise starving.
Its the combination of birds being available and regular food not being available and then one has to be successful enough at it to survive. Catfish are pretty opportunistic feeders, which is perhaps why they would consider birds to be food if they were otherwise starving.