Hi Martin,
You are correct, Eagle Owls are widely
kept in the UK and I believe elsewhere in Europe, the US, and Asia but are often not properly trained as falconry birds. They are
well known to be able to catch very large prey items in the wild (incl. claims
of ¾ grown wolves (!) and certainly many foxes) but I believe falconers use
them mainly for shows and occasionally for rabbit hunting. They are apparently
not great falconry birds as they are notoriously difficult to train to hunt.
There has been a huge amount of debate
about their status in the UK – Are all the free flying birds escapees or could some be
genuine vagrants? Some groups believe they could be partly self-established in
the UK and
have arrived under their own steam. These groups point out that Eagle Owls have
increased in numbers and expanded their range in continental Europe and that other species
of owls are known vagrants to the UK. A substantial paper arguing this case was presented by the one of
the Owl/Falconry groups but I think they clearly had their own agenda. They
released this paper as a ‘scientifc publication’ but I don’t
believe it was independently peer-reviewed.
I think most knowledgeable birders in the UK believe the free flying
Eagle Owls are all escaped birds. The BOU (British Ornithological Union) certainly
maintains European Eagle Owl as a category E species (likely escaped, non
vagrant bird).
Owls such as Scops Owls and Hawk Owls that
are known to occur in the UK as genuine vagrants are migratory and irruptive species,
respectively, that can easily travel long distances. However, the European
Eagle Owl is a largely resident/sedentary species that is not prone to wide
ranging dispersal and would probably have some difficulties crossing a large
expanse of open water such as the English
Channel. Similarly Tawny Owls, a
common breeding species in the UK, are a largely sedentary species that have only very, very rarely
made the short crossing to Ireland.
One of the reasons for such hotly contested
debate in the UK is that as an escaped species the Eagle Owls are unprotected by
law. There are now several well known breeding pairs and the eggs at one of
these sites have been repeatly smashed and at least one of the breeding female
birds was shot. Showing just how many free-flying Eagle Owls there are in the UK, it was soon replaced by
another female and a new pair was formed. Many of these birds still show traces
of their jesses and are of undoubted captive origin. I think it is because of
this persecution that the Owl/Falconry group put out their paper claiming Eagle
Owls were potentially true vagrants and were establishing naturally occurring breeding
populations in the UK. The paper lobbied for the change in status from category E
(escaped birds) to category A (naturally occurring) in the BOU lists and would
thus be able to get some sort of protections for them.
However, the situation is coloured by the
fact that Eagle Owls are well known to kill other birds of prey up to, at least,
the size of a Northern Goshawk. One of the pairs in the UK is thought to have
killed a female Hen Harrier as the remains were found very close to an Eagle
Owl nest. Hen Harriers are a protected species in the UK and thus many
conservationists/birders would agree that probable escaped birds, even as
magnificent as an Eagle Owl, such not be allowed to spread unnaturally if they
are killing a vulnerable breeding species. Again further complicating matters a
grey wing, initially thought to be a male Hen Harrier wing, was also found at
one of the nest sites but DNA analysis proved this to be a Common Gull wing and the pro-Eagle
Owl groups jumped on this claiming there was no real evidence that the UK Eagle
Owls were killing Hen Harriers.
My personal opinion is that they are more
than likely all escaped birds. There was a really good summary of the status of
Eagle Owls in the UK in the British Birds journal a few years ago and I am pretty sure
there are scanned copies of this article on the web that I can find for anyone that
may be interested.
Cheers Dan
-----Original
Message-----
From: martin
butterfield [
Sent: Tuesday, 31 August 2010
12:41
To: Philip Veerman
Cc: COG
List
Subject: Re: [canberrabirds]
Escaping birds
Thanks
for those comments Philip.
Here is a link http://www.rspb.org.uk/ourwork/policy/species/nonnative/eagleowls.asp
to the article from which I extracted material in my last message. The
only suggestion I can find as to why people might keep eagle owls is in the
reference to falconry (although when - in my youth in the UK - I hung out with
falconers I never head of anyone having an Eagle Owl). I agree that there
is a leap from the number of certificates to the inference that there are a
large number of birds in captivity.
WRT to the last bit what I was hoping for was someone who is connected with the
captive bird situation in Canberra (or indeed elsewhere in Australia) to
say something like "Our members, who have got n birds of species A, have
reported z escapes per year.". This would be to be a
useful topic for research by someone concerned about the impact of feral birds.
Martin
On Sat, Aug 28, 2010 at
6:31 PM, Philip Veerman <> wrote:
That is
curious. I wonder why would anyone want to keep an Eagle Owl. I wonder if they
would cost more to feed than a dog. Most likely they would be fed on rats. I
agree those figures sound like a high escape rate. Or are people not wanting
them any more and releasing them, and calling that an escape. I don't follow
the logic about counting certificates if a bird is sold enabling a suggesting
that the number kept
in captivity is likely to be considerably higher than this. Surely one bird could be sold many times. They can live a long
time. I can imagine people would get bored with keeping one.
About
your last bit, it is difficult to describe, as we know so little about how long
individual escaped birds survive. Beyond that, as you know, the GBS Report
comments on this issue for Canberra, as our GBS is a probably unique position
to contain relevant (even if patchy) data. I don't know of any study that
offers anything more than the GBS Report does (as minimal as that was),
otherwise I would have cited it in the references................
-----Original Message-----
From: martin butterfield [
Sent: Saturday, 28 August 2010
1:57 PM
To: COG List
Subject: [canberrabirds] Escaping
birds
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?
