Escaping birds

[martin butterfield <>]

As a result of reading about an Eagle Owl (in the UK) atacking a Hen Harrier I checked out the RSPB site to find about Eagle Owls, which I thought got no closer to the UK than the Alps.  It seems there are quite a few in the UK derived from escapees.  I thought it might be of interest to reproduce the words of the RSPB about this situation.

"The eagle owl has been known in captivity in this country since at
least the 17th century and many were brought from India during the 19th
century. Eagle owls are very commonly kept in captivity - often by
people who are not falconers. There is no formal requirement to register
 these birds, but a certificate is required if a captive bird is sold.
In the 10 years to 2007, 3,370 such certificates were issued. The number
 of eagle owls kept in captivity is likely to be considerably higher
than this.

"Of the 440 captive eagle owls registered with the Independent Bird Register between 1994 and 2007, 123 (28%) were reported to have escaped. Of these, 73 were reported as not having been recovered. This equates to 9-10 escapees per annum, of which 5-6 were not recovered. If the same escape rate is applied to a conservative estimate of the British captive population over the same 13-year period, around 65 birds could be expected to escape each year."

This seemed an astonishing number of escapes.  I wonder if anyone has done any studies of the escape rate of Australian captive birds?