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Biggest Slimbridge family on record!

Posted on 18 December 2012 by Julia Newth @ Slimbridge in Bewick's Swan diary

Everton (left), Rovers (right) and their big brood (J S Lees)

The largest Bewick’s swan family ever recorded at Slimbridge has flown in! We thought we were seeing double when Slimbridge regular Everton brought his new mate Rovers and their brood of six cygnets to the reserve! This huge family party of eight form an imposing force on Swan Lake. They have joined the 200 other Bewick’s at the afternoon grain feeds and are currently spending their days grazing on surrounding fields, re-fuelling after their 2,500 mile migration.

Bewick’s swans usually lay between one and six eggs on breeding grounds in arctic Russia but generally only up to four (and more often one or two) hatch and survive to reach wintering sites in Northwest Europe.

 

After laying the eggs in June this year, Rovers, who is female, will have incubated them for 29-30 days with some help from Everton. During this vulnerable time, both parents will have closely guarded the nest and protected their brood against predators such as Arctic foxes, wolverines, white-tailed eagles and skuas just to name a few. This would have been a perilous time for the family. Then would have come a period of rapid weight gain with the swans feeding day and night on the abundant wetlands vegetation and berries. When September arrived, the family escaped the arctic winter by embarking on their long journey to reach us.

So is this an early sign that the Bewick’s have had a good breeding season? Last weekend, observers across Europe braved the cold and headed out to the fields with one aim: to count the number of cygnets and the number of adult birds. Dutch ornithologists Jan Beekman and Wim Tijsen are currently collating the data which will ultimately reveal whether the population has bucked the trend of recent years and managed to successfully breed this year. Results to be announced soon…..

  • hucks67

    “After laying the eggs in June this year, Rovers, who is female”

    It would have been remarkable if Everton had laid the eggs ! :)

    Will you be ringing/naming the cygnets, to see if they also have large broods ? This is probably just a lucky one off where the eggs were of a good quality and the parents were able to look after them well. But it would be interesting in the future if you could look back and see whether the breeding line is very strong.

  • hucks67

    When you look at the picture, it looks like 3 adults and 5 cygnets. Does Everton have 2 wifes or do they have one of last years cygnets still staying with them ? It is just that one of the cygnets has whiter feathers than the others. Perhaps you have had clearer views of the group than the picture, which confirms a brood of 6.

    • John

      Hey Hucks67, if you look closer, behind the front adult there are two cygnets. You can see a red and black bill just below the front adult’s bill

      • hucks67

        I see. So there are 3 adults and 6 cygnets in the picture. I wonder if the adult is related to Rovers and Everton, as it seems to be within the group.

  • Colin Butters

    The sentence including Rovers being female is to indicate that the female does most of the incubation (in some species it is the other way around, e.g. Phalaropes) when the names do not readily indicate which sex is which. That is how I read it.
    The cygnets will not be named unless they are caught in the annual swan catch and given a ring to identify them. The unique bill pattern, the other way of making an identification, does not fully form until after the birds have left on their spring migration so without rings or bill pattern there would be no point in giving names as they would not be identifiable next winter. I believe I am correct in this.

  • mowarren

    Wow! The previous record for Slimbridge was five cygnets’(The swans fly in’ P&P Scott 1983) so it’s been a long time since such a large family has graced the lake. There are six cygnets and three adults
    with the ‘interloper’ leading the group in James’ photo? Do swans with big families seek the help of unattached adults to ensure better protection of young? Or could it be that the odd one out lost it’s mate after cygnets hatched and it tagged on to another family for support which would mean that Rover & Everton didn’t actually hatch all the cygnets in this group Are they still all sticking together? A great event in any case! Good news from Europe that breeding success is probably up on last year.
    Fingers crossed for more Bewick’s swans from now on!

  • julia

    Hi All, thanks for your comments! Yes, the extra adult in the photograph is an unrelated interloper that just happened to be next to them. This adult has not been associating with the family. We are certain that they are a family with six cygnets. We have been watching their behaviour very closely and all six cygnets stay within close proximity of the adults and the individual members have been reaffirming their bonds with various displays. The family of eight also defend their territory as one strong unit. Relatives (close or distant) may certainly assist a family in defending a territory and occasionally an unrelated lone cygnet may be adopted by a family to boost numbers in the unit and increase their chances of winning territory. In these cases, the lone cygnet will usually be at a different stage of development that the rest of the brood and the bond with other members of the group will not be as strong. These cygnets appear to be all at the same stage of development and are strongly bonded with one another.

  • Darcia

    I visited a week or so ago and during the feeding talk the warden said that it was six cygnets with one adult. Did something happen to Everton as I think it was said that they were with Rovers?