Blogger: Kim Matthews, Campaigns Officer 

It’s always the quiet ones! At least that is what my grandmother used to say.  So what started me reminiscing on my grandmother’s pearls of wisdom? 

It all began with the RSPB's Big Garden Birdwatch.  In the aftermath of the big weekend there were rumblings on the Twittersphere about having only seen dunnocks during their hour.  LBJ’s (little brown jobs!) are often dismissed as dull and boring, but I’m telling you, when it comes to the dunnock you seriously need to reconsider that opinion!

For a start, take a closer look at their colours, they are like stripy feathery tigers stalking through your shrubs and hedges.  Then there is the song, it’s quite simply beautiful.  It came as a pleasant surprise the first time I realised the song I was hearing in my garden was actually coming from the beak of such an unassuming little bird (I found a cracking clip on YouTube for you: Dunnock Singing).  Then of course there is also the fact that their love life is one of the most complicated and varied that you can find!

I should start by doing the "science bit" and explaining the different mating systems found in the animal kingdom:

Monogamy – nice and easy, one male and one female and 90% of birds fall into this category (although we now know that most are not strictly monogamous at all!).

Polygamy – much more complicated and actually broken down further into:

Polygyny – one male, several females

Polyandry – one female, several males

Polygynandry – the technical term for promiscuity!  Several males, several females.

So what makes the dunnock so unusual?  Well, they can have literally any of the above systems and it all depends on how their food is distributed.  Females defend a territory against other females.  Where food patches are densely clumped together female territories are small and you find one or sometimes two males will have access to both females.   

When food is sparsely distributed and territories larger, two males will move in to defend one female.  One of them will tend to be dominant and they will compete over who gets access to the female.  The alpha male will try to guard his missus but the beta male will be constantly trying to sneak a cheeky mating.  The female not only accepts the attention of the beta male she goes out of her way to encourage him by trying to give the alpha male the slip, the reason being that the beta male will only feed her chicks if he has managed a sneaky mating with her.  However she has to be super sneaky, if the alpha male spots her cavorting around with the beta male he will reduce the amount of food he brings to the chicks.  Chicks fed by both males have a much better chance of survival so it’s in her best interest to keep both males happy!

I hope next time you see a dunnock you will think differently of them because like I said, it’s always the quiet ones!

Photo by John Bridges (rspb-images.com)