• Home
  • Blog
    • Online reporting
  • Galleries
    • Birds
    • Other vertebrates >
      • Mammals
      • Lizards
    • Insects >
      • Moths and butterflies (Lepidoptera) >
        • Leps
      • Dragonflies and damselflies (Odonata)
      • Flies (Diptera)
      • Beetles (Coleoptera)
      • True bugs (Hemiptera)
      • Shield Bugs (Heteroptera)
      • Leaf Hoppers (Homoptera)
      • Sawflies, wasps, bees and ants (Hymenoptera)
      • Scorpionflies (Mecoptera)
      • Grasshoppers and relatives (Orthoptera)
      • Lacewings and relatives (Neuroptera)
    • Other bugs >
      • Spiders and allies
      • Snails and slugs
  • Birding
    • Travel >
      • China (Happy Island)
      • Gambia
      • Malawi
      • Lithuania and Poland
      • Morocco
      • Nepal
      • Norway (Arctic)
      • Spain (Extremadura)
      • Thailand
      • Tibet
    • Garden birds
    • Microbigyear >
      • Species list
      • Background
      • Pictures
      • Flickr
Nature photography by Frode Falkenberg

Uncovering a turbulent childhood

19/3/2012

Comments

 
Gulls are variable. They are the most diverse bird-group concerning plumage variation within species and age-classes. To add more confusion to the aspect of identifying gulls, they also differ in the timing of their moult. On top of this, some birds loose feathers without "wanting" it. These are some of the aspects why gulls are the most intriguing birds todo in-depth observations off.
Picture
At first glance a normal first winter Common Gull, but really strange when studying the details.
An odd white tail
Yesterday I saw this freaky Common (Mew) Gull in Bergen. The plumage and bare parts tells me it is a bird that is less than a year old. At first glance it gives the impression of being in its first winter (first basic) plumage. Scrutinizing the bird a bit more careful reveals a nearly white tail. Common Gulls at this age should have a wide black terminal band on the tail. In second winter plumage they can look like this, although usually completely white. Has the tail been shed? We'll leave the tail-feathers for a moment, and go on studying more plumage characteristics. The wing looks a bit strange.  
Picture
The primaries on both left and right wing.
Picture
This is how the primaries should look like.
Strange set of primaries
There is something about the outer primaries. Some feathers are brighter than normal, and both p9 and p10 show small mirrors (the two outermost primaries). P9 has a larger mirror than p10, which only has traces of one. Mirrors are rare in first winter Common Gulls, but second winter birds show mirrors on these two feathers, but with a large mirror on p10 and a smaller one on p9 (sometimes not present). From p7 and inwards the primaries have large light grey areas, giving the hand a rather unfamiliar look. When zooming in, some interesting features are revealed. P10 is lighter brown than p9, and the latter seem a bit short compared to p10 and p8, indicating a not fully grown feather.

Two generations primaries
Gulls moult their primaries from the center of the wing (starting with p1, the inner primary, working its way gradually to p10. Does this mean that the bird has shed p1-p9? Apparently, but once again when looking on each feather you can see a contrast between the dark areas on p5-p1 and p6. P5 does also show dark smudging on the outer web, which is perfect for a first generation feather. Summing the feather features up the conclusion is that p9 and p7-p6 have been shed and regrown. I think P8 on the left wing is an old first generation feather, and it is missing completely on the right wing.

When birds accidentally loose feathers, they try to replace them as fast as possible. In particular feathers crucial for their flying ability, such as primaries, secondaries and tail-feathers. Did this gull experience something that made it unintentionally loose some feathers? Probably. I am sure that the primaries p9-p6, minus p8, are moulted into second generation, but I am not completely sure about the tail, since all are the same generation. It may be an aberrant first generation tail, but probably not. The really strange thing is that it has moulted the same three primaries on both wings! This is how gulls moult of course, synchronous on both wings, but this is not the right order of things, and it is not at all the season to observe second generation flight feathers on first-winter Common Gulls.

So, what happened to this gull? Did it hit a wire, interact with a predator, or maybe was shot by a hunter? Did it walk around with no tail and seven central primaries missing some time last autumn? Whatever happened the result is a second calendar year Common Gull with seven (4+3) shed primaries, six of them regrown, and a really aberrant tail that probably is also renewed. Beautiful!
Comments

    Storymaps

    Picture
    August 2024: Tracking Norwegian Black-tailed Godwits (NO) 
    Picture
    July 2023: Black-tailed Godwit fieldwork in Northern Norway (NO) 
    Picture
    June 2023: Great Snipe fieldwork at Hardangervidda, Southern Norway (NO)
    Picture
    November 2018: ​Fieldwork in three IBA's in Nepal (EN)

    Blog archive

    February 2025
    May 2024
    October 2023
    May 2023
    November 2022
    February 2022
    June 2017
    May 2017
    February 2017
    December 2016
    September 2016
    May 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    May 2015
    March 2015
    February 2015
    January 2015
    December 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    March 2014
    February 2014
    December 2013
    November 2013
    October 2013
    September 2013
    August 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    December 2012
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    April 2012
    March 2012
    January 2012
    December 2011
    October 2011
    September 2011
    May 2011
    April 2011
    March 2011
    March 2010
    October 2009
    February 2008
    April 2007
    October 2006
    September 2006
    June 2006
    October 2005
    June 2005
    April 2005
    October 2004
    September 2004
    May 2004
    March 2004
    November 2003
    October 2003
    September 2003
    April 2003
    March 2003
    November 2002
    July 2002
    June 2002
    May 2002
    April 2002
    December 2001
    November 2001
    October 2001
    September 2001
    November 1999

    RSS Feed

Bird Galleries

Non passerines
​Passerines

Animal galleries

Mammals
Lizards

Spineless galleries

Moths and butterflies
​
Damselflies and dragonflies
Spiders and allies
​Snails and slugs
Flies
Beetles

Social

contact

All content on this site © Frode Falkenberg. ​Go to the contact form for comments or if you want to use material from the site.