Also out of interest is that apparently there is a record of Pel's seen in Cape Point Nature Reserve in 1940. So perhaps they can migrate to the Cape.
I have heard of this "unverified"(well at least to my ears) and very old record of it in Cape Point. The only other record I know of is as shown in our bird guides dotted by a red x
in the northern Cape and which is also quite an old record and therefore I am not sure how well verified.
But my point remains, why would a bird not known for its migratory skills travel 1000's of kilometers away from its stronghold to a Cape Town suburb? Personally I think the odds are stacked more against it being a genuine vagrant than it being an escapee from someone's illegal private collection or illegal trade in the area.
I am not sure how long this bird has been in the area, but too me it looks like an adult bird and one couldn't even argue that it was a young bird, getting displaced or out on the look for new territory. Coming down along the coast from KZN it would surely have found much more suitable habitat long before it had reached Cape Town, not true?
Recent new additions to the Cape such as Abdim's Stork, Wahlberg's Eagle and Montagu's Harrier are all migratory birds and one could very well expect to find such birds out of their normal distribution. Another 2 recent additions are Tawny Eagle and Long-crested Eagle, which have gradually started to edge lower south and west in recent times. So even that was imminent.
As for why they don't occur in the Knysna area. Personally I think that the climate is too cool and perhaps even too wet for most parts of the year. Even in summer those forests are freezing! In my inexperience as a climate expert, the Knysna area and the natural habitats of Pel's differ too much.
Hopefully my suspicions are wrong. And I hope to be proved wrong. But until such time, I will remain very skeptical about this bird as being ticked as a genuine wild vagrant. Maybe we just don't understand the habits of these owl well enough and that there is a treasure chest of info we still have to unlock unknown to scientists.