Friends of Portbury Wharf Nature Reserve


APRIL 2017 - Issue 8



You may see some unusual activity on the nature reserve this month as National Grid carries out surveys to gather information about the ground conditions. They will use this information to help design the underground cable sections, the new overhead line and the temporary haul roads that they will need to access the construction sites.

This ground survey work is estimated to take 2-3 weeks given favourable weather conditions. This will involve excavating trial pits 1m deep and up to 2m square and borehole drilling 15-30m for core samples of soil and rock for testing. The land will be reinstated after.

There are public information notices posted around the reserve.

If you have any questions about this work you can contact the National Grid Community Relations Team:

Tel: 0800 377 7347 

Keep an eye on our Facebook page for any updates.

 at Portbury Wharf

One of the great pleasures of visiting Portbury Wharf is the sight of the swans. These impressive and handsome birds are mute swans (Cygnus olor), the UK's largest and heaviest flying bird which is resident all year round.

Do you know?

  • Despite its name the mute swan is not mute but it is less vocal than other swan species.


  • A female swan is a pen, a male a cob and a baby swan is a cygnet or swanling
  • The cob has a larger black knob at the base of its bill than the pen
  • They measure up to 170cm in length (5ft 6in)
  • The wingspan of a large cob can be 2.4m (8ft)
  • The mute swan is our heaviest flying bird, with the cobs typically weighing in at 11-12kg, and the pens slightly smaller, though the heaviest recorded was in Poland with a weight of 23kg, that’s 51lb in old money
Non-breeding swans, youngsters and singletons, tend to gather in flocks. Locally this occurs in the Portishead Marina and on the pools in the nature reserve. In very cold weather they will also venture out into the estuary to escape frozen water. Look out for the large groups of swans feeding in the fields between Weston-super-Mare and Clevedon.
As well as grazing on grass, mute swans feed on aquatic vegetation by up-ending in deep water or by simply using their long necks in the shallows.

Do you know?

  • There are four pubs in the UK named "Cob and Pen"


Being such a large bird take-off requires a bit of effort. They paddle hard to gain speed, then begin "running" across the water until they have enough momentum to become airborne. The sound of their webbed feet slapping the water in ever quickening steps sounds like many gloved hands clapping gently in appreciation of their efforts.
Once airborne the breathless sound of wings scything through the air makes you turn to watch, a sound that, in the right conditions, can be heard over a kilometre away.

It is such an evocative sight so keep your eyes and ears peeled when you visit the reserve, though from June to August they tend to be grounded with family duties to attend to.

Do you know?

  • The collective name for a group of wild swans is a herd and it is a fleet for captive ones
  • Someone with a fear of swans has cygnophobia or kiknophobia
  • When sleeping on land mute swans often stand on one leg to reduce body heat loss


Mute swans pair for life and defend their territory against intruders. Nests are built on mounds, either on islands or at the water’s edge, where as many as 10 eggs can be laid over a period of 2 to 3 weeks. Once the last egg is laid then incubation will begin. The cygnets will hatch after nearly 6 weeks and will be tended to by both parents until the autumn.
Whilst the adults are predominantly white in colour the cygnets are usually a sooty grey. They grow very quickly and are almost the size of their parents by 3 months of age.
Their grey colouration is gradually replaced by white, at which time the parents will chase the cygnets away from their territory.
However, we seem to be seeing an increase in paler cygnets. These have a leucistic gene which causes some of their feathers to be lighter, almost white, in colour.

Which Hans Christian Andersen fairy tale is about a mute swan?

answer at the bottom of the newsletter.


Mute swans are very territorial and this one on the Lake Grounds was harassing a Canada geese family.
The gander had to work hard to distract the swan away from his family.
. . . but the swan was persistent.
There was a good deal of chaos 
. . . and a scattering of goslings
. . . before the gander managed to distract the swan sufficiently to enable mother and goslings to swim safely away.


One of the main threats to swans are overhead power lines, especially in places like Portbury Wharf where the lines are close to the water and where the swans are trying to land.

Roads can also be a problem in the wet and in poor visibility. 
Flying swans can mistake the wet road for a river and try to land – both damaging themselves in the process and also possibly being hit by a passing vehicle.
Predation by dogs and foxes is also a problem especially when the swans are in shallow water or on land.

Fortunately most of our Portbury Wharf dog walkers are very responsible and keep their dogs well under control, but sadly we have still had swans maimed and, worse still, one died as a result of a dog attack this winter.


In the UK the mute swan is offered full legal protection, which means it is an offence to kill, capture or hold one in captivity, take their eggs or disturb their nests.

Though there is an even older piece of legislation protecting this swan which dates back to the 12th Century.
To stop commoners hunting the royals’ favourite dish, the Crown claimed ownership of all mute swans in England and Wales.

This legislation has never been repealed, so today the mute swan is the Queens’ bird and so taking or killing a swan could be deemed an act of treason.

Do you know?

  • In 1874 Queen Victoria's youngest son, Prince Leopold sent Dr Ackland, one of his tutors at Oxford, a swan for their family Christmas dinner. Dr Ackland’s comments are not recorded.
Swans at sunrise over Royal Portbury Dock


While the mute swan is the most common and widespread swan in the UK there are 3 others which you may see: Bewick's swan, whooper swan and the black swan.

The Bewick's and whooper swans are winter visitors to the UK and are smaller than the mute swan. Interestingly the mute swan is more closely related to the Australian black swan than to these two white northern species.


Bewick's Swan
The distinctive yellow markings on its bill are unique and allow researchers to identify and record individual birds. These records have shown that the birds almost always pair for life and that they return to the same over wintering sites year after year.
Due to changes in the climate, illegal hunting and the loss of wetland and other habitats the numbers of migrating Bewick's have almost halved since the mid 90s.

After fattening themselves up on their summer feeding grounds in Russia, Bewick's swans begin the long migration south before the arctic winter sets in. They usually start arriving in the UK in mid October with the majority over wintering in eastern England. Some Bewick’s also migrate as far as the Severn Estuary and can be seen at WWT Slimbridge during the winter months.

Do you know?

  • The Bewick's swan is named after a renowned illustrator, wood engraver and natural history writer, Thomas Bewick (1753 - 1828).


Whooper Swan
A whooper swan has more yellow on its beak than a Bewick's swan. This colouring extends down to a point on the side of the beak. It also has a longer flatter head and a longer neck.
They are very powerful fliers and can migrate thousands of miles at enormous heights from their summer breeding grounds in sub-artic Eurasia to their over wintering sites situated in eastern Asia and southern Europe.
The Icelandic whoopers migrate to Ireland and the UK across the North Atlantic, though they usually do not reach as far south as the Severn Estuary.

Do you know?

  • The whooper swan is the national bird of Finland


Black Swans
The black swan is not native to the UK and originates from Australia.

Like the other swan species both male and females share the incubation and rearing duties of their cygnets.
Black swans were introduced in Victorian times to the UK and some subsequently escaped from captivity.

Escapee black swans have struggled to establish breeding colonies possibly due to the mute swan's fierce defence of breeding habitats preventing them from gaining a foothold, although around twenty breeding pairs can be seen at Dawlish in Devon.

Next time
"There Be Dragons"

The fairy tale is the UGLY DUCKING
First published in Denmark in November 1843
Copyright © 2016 Friends of Portbury Wharf Nature Reserve, All rights reserved.

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*Photo credits in full:
Header image and image 21 - courtesy of John Rickard

Images 1 - 5 & 9-15 & 17-18  - courtesy of Hilary Kington
Images 6 and 16 - courtesy of  Chris Sperring MBE
Following images courtesy of

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