Monday, 16 July 2012

What are 24 eggs doing in one nest box?

Strange things are going on in the tufted duck world and more than one duck has been using the nest box (pictured below).     Some of the eggs are stacked on top of each other - I counted at least 24 yesterday.

 Twenty four eggs seems rather excessive

 A while back I looked inside one of our riverside nesting boxes and found two eggs.  The next day there were five, the following day seven, and the day after ten! Ducks only lay one egg a day so we were mystified. 

At least two tufted ducks and possibly a third (or a mallard) have been using the same nest.  By early July there were twenty four eggs. Then, one day, I saw a female tufty swimming away from the nest with an egg in her beak.  She ate the contents and returned to the nest. The next day, the same thing happened and we think that, with so many eggs in one box, several may have cracked while being rolled?  Alternatively, if several tufties were sharing the same nest perhaps one was trying to get rid of its rival's eggs.

We wondered how the nest sharing would work and whether the females would take it in turn to sit on the eggs. One female, however, 'laid claim' to all the eggs and 'saw off' her rivals.  The adjacent nest box soon had two eggs but was later abandoned. Then the eggs disappeared but, bizarrely, two damaged eggs turned up inside another nest box on the top deck.  They hadn't been there a couple of days before so we think the crow was the thief!

The resident tufty heading back into her nest box

Several weeks later a tufty laid a fresh egg inside the adjacent riverside box and there are now four but I think these have also been abandoned.  In the meantime another female tufty nested in dense bracken in our bog garden but the fox must have discovered the nest and taken the eggs.   Last week a family of mink were found in the 'hold' of a neighbour's houseboat.  Mink are killers for the sake of it so I'm worried for the safety of the nesting ducks.  I've heard that three mink have been trapped (one a youngster) but islanders think there are more around.  I hope not.

Teenage great crested grebe racing to grab a fish from one of its parents

The attrition rate amongst our smaller water birds has been ninety nine percent this year so far.  The only known survivor is a young great crested grebe which survived in spite of the fast flowing river following months of rain.  Against all odds . . . and a strong current, it has managed to survive and is looking quite strong and healthy. During a brief and very welcome break from persistent rain the sun shone for half an hour and I managed to get out with the camera and photograph the young grebe rushing for a fish from one of its parents.  In spite of the rain it was a warm day and there were plenty of small fry to be had so the youngster was full after a couple of hours.  We just hope that it makes it to adulthood.

 The young grebe keeping a watchful eye out for its parents in the hope of more food

 Storm clouds over Hampton

The sky was so black overhead and when I glanced downstream I noticed this amazing dividing line in the sky.  Not long after I took this picture we endured another dramatic deluge!  Rumour has it that scientists in Antarctica are experimenting with weather patterns in an attempt to control future droughts, floods and heatwaves etc. If it's true, then it's time they stopped interfering with Nature and the environment!

One piece of promising news is that HB is back.  She's been dithering about, trying to decide which hanging basket to nest in, and has led me a merry dance!  First of all it was going to be the basket she used last year on the outside edge, then she opted for the garden side one that she used in the Spring. I duly planted up the other basket but she decided that she fancied the riverside basket after all and kicked out some of the plants.  I then removed all the plants so that she could her use her preferred basket only to find that she'd changed her mind again the next day and has now settled for the one overlooking the garden.  She currently has seven eggs and I've re-planted the riverside hanging basket!