Black Swans in Reading

[floraphil]

Recently, I've noticed three black swans swimming and feeding with a group of mute swans on the Kennet and Avon canal in Reading. As black swans originate from Australia, I'm assuming they have escaped from a private collection and have become naturalised. Does anyone know how long they have been established in this area?

[Dorts]

Many, many years ago (1960's), my father had a boat moored on the Thames at Tylehurst, just up from Reading, which I would occasionally use at week-ends. I clearly remember seeing a few Black Swans in and around Reading during that time.
So it is possible a small population has been extant in that area since then.
Dorts.

[RoyW]

Black Swans aren't really 'established' anywhere in the UK.

They are relatively common in captivity though, and when they do escape (or perhaps are released?) they can remain present in an area for several years because they are fairly long lived birds. Pairs have sucessfully bred at various sites around Britain, but breeding sucess generally seems to be relatively low probably with more nest failures than sucessful breeding.

[Dorts]

A recent BTO Survey had 500 reports of black swans, in at least 170 different locations around the UK.
Of these locations, 37 are thought to be sites where the birds are breeding.

The Report stated, "They are cropping up all over the place now. We have been surprised by the numbers we have found. This looks like a major increase and once we can see the evidence we will assess it to see if it now qualifies as a self-sustaining population.
It will now need to be looked at to see if the black swan is added to the British List."
Dorts.

[RoyW]

Originally Posted by Dorts

A recent BTO Survey had 500 reports of black swans, in at least 170 different locations around the UK.
Of these locations, 37 are thought to be sites where the birds are breeding.

The Report stated, "They are cropping up all over the place now. We have been surprised by the numbers we have found. This looks like a major increase and once we can see the evidence we will assess it to see if it now qualifies as a self-sustaining population.
It will now need to be looked at to see if the black swan is added to the British List."
Dorts.

Yes, and I see them regularly at sites near me (where they have also bred, once sucessfully fledging young, but unsucessfully in several years). Near me they tend to have favoured sites where they can usually be found, but occasionally wander to other sites nearby - especially when forced to by disturbance or if the water freezes. For several years now there have been 2-3 present on one particular gravel pit, and occasionally nearby waters - and since most swans live for an averagae of 9-10 (and individuals potentially for over 20) years I would expect them to continue to be present for several more years at least.
They will then 'dissapear' when they die (but by then it is possible that other escapes will have found other waters nearby to suit them).


The fact that fairly large numbers are 'at large' in the UK does not necessarily mean that they are self sustaining. To establish this the number of young that are sucessfully fledging, reaching breeding age, and finding a mate in order to produce future generations needs to be considered. With long lived species there doesn't need to be a particularly large number of new escapes each year to allow the numbers to increase, even if the number of young that the species is producing in the wild isn't high enough to replace the number of older individuals that die each year.


The most recent "Non-native breeding birds in the UK report", which deals with 2006-2008 gives reported totals of 11-14 breeding pairs of Black Swans in 2006, 11-20 in 2007, and 16-25 in 2008 (though does say that there may be an element of under recording). The 2003-2005 report can be read as a pdf here. (the lower number of breeding pairs for each year referes to the confirmed pairs, though not all of thee will have sucessfully raised young - the higher number includes the presence of birds that may not have even attempted to nest).
In 2005 a review of the status of non-native species breeding in the UK concluded that Black Swans were not self sustaining due to the small number of breeding pairs and the wide distribution spread - personally I can't see that that will have changed. (Note that Barnacle Goose, which was added to category C of the British list in the 2005 review, had at least 120 confirmed pairs at that time, and Snow Goose was also added to category C based solely on a population confined to a restricted area in the Hebrides).

[faz]

i remember a post about this last year or first part of this year called black swans ?

[floraphil]

Interesting stuff. I'm convinced the report has under-recorded the amount of breeding pairs and as I'm moving very close to where the black swans reside soon, I'm going to keep an eye on them. I must admit my head turned when I heard them call, I wasn't expecting it at all and I quite like their bugle like noise!!

[Hobjob]

IIRC the Queen owns the 'swans' on the Thames.

Does she also own the Black Swans?

[solus]

It's only the Mute Swans as far as I am aware seeing as how the Black variety are escapees or deliberate (and illegal) releases from collections.

Perhaps they'll prove to be trouble in years to come and (if it's not too late by then) need to be "dealt with"?

[RoyW]

Originally Posted by Hobjob

IIRC the Queen owns the 'swans' on the Thames.

Does she also own the Black Swans?

Originally Posted by solus

It's only the Mute Swans as far as I am aware seeing as how the Black variety are escapees or deliberate (and illegal) releases from collections.

The Queen doesn't even own all of the Mute Swans on the Thames - the Vitners and Dyers livery companies have also maintained their right to own swans on the Thames and, along with the Queens representatives, still take part in 'swan upping' on the Thames to mark "ownership".