'Harry Potter' author JK Rowling has pleaded with fans not to copy the young wizard by having owls as pets.The 39-year-old writer is worried after demand for the birds, which feature heavily in both the 'Harry Potter' films and books, soared as she believes they will have to endure miserable lives stuck in cages as youngsters try to copy Harry.She wrote on her official website: "If anybody has been influenced by my books to think an owl would be happiest shut in a small cage and kept in a house, I would like to take this opportunity to say as forcefully as I can: YOU ARE WRONG."The owls in the 'Harry Potter books were never intended to portray the true behaviour of real owls."JK, who recently gave birth to her third child, also urged fans that if they must have an owl, they should sponsor one instead and pay it regular visits."If your owl-mania seeks concrete expression, why not sponsor an owl at a bird sanctuary where you can visit your owl and know that you have secured him or her a happy, healthy life."