Channel-billed Cuckoo

["Philip Veerman" <>]

Hi Bob,

 

Based simply on what you are describing I would add: If the fear of large birds that look like raptors is instinctive and it probably is, then whether the birds have just arrived or have been there every day, is of little or zero relevance. Unless the birds have the capacity to learn what it is then having seen it before won't over ride the instinct. For example Magpie-larks never learn that their reflection in the car mirror is not a nasty intruder. They just respond to the image they see. I was suggesting that the rosellas see the thing and respond with raptor avoidance behaviour simply because, coincidentally, that is what it looks like. To do so is "wise" and reduces risk. That of itself is no reason to suspect that the cuckoos have any negative impact on the rosellas.

 

Philip