Bird of the week - Barn owl

Watching a barn owl floating silently across a field at dusk is a thrilling experience.  I was very pleased to see this pair hunting in late afternoon while there was still good light.

Barn owls are mostly nocturnal but those in the UK are at the northernmost edge of their range and are more likely to be seen out hunting at dawn and dusk, particularly after poor weather.  Their favourite prey is the field vole such as this one, identifiable from its short tail and blunt nose.

Barn owls were severely affected by DDT and other poisons in the mid 20th century but the population has recovered. The barn owl is now green listed although the UK population is only 4000 pairs.

Barn owls are birds of open countryside and farmland and these BTO BirdAtlas maps show that they are more common in the eastern half of the country.

Thomas Bewick made this woodcut of a barn owl for A History of British Birds (1797). 

Barn owls are found throughout most of the world but in recent years some authorities have split them into three species.  Ours, Tyto alba, is now the western barn owl.  The American barn owl, now Tyto furcata, was painted by John James Audubon.

Archibald Thorburn also painted the barn owl.

You can listen to Miranda Krestovnikoff's BBC Radio 4 Tweet of the Day here and to Chris Packham's here.  You can learn more about barn owls via the Barn Owl Trust's website here.  And watch a short BBC video on how barn owls fly silently here.

My first walk round the pond - week 13

My original plan was to walk round the pond once a week from April to October this year, mostly looking for dragonflies, and to put a weekly report on this blog.  But then I also registered the walk as a BeeWalk with the Bumblebee Conservation Trust.  Their bee walks start in March so I went a bit earlier.  The protocol demands a fixed route of 1-2km to be covered in about an hour each month, recording all the bumblebees seen in a 4m square imaginary box in front of the observer.  I have seen lots of bumblebees at the pond in previous years, mainly red-tailed bumblebees (Bombus lapidarius) as far as I remember.

This was the first time I have been this early in the year so it was interesting to look around.   There are two ponds on the site, small and large.  Here is a buzzard's eye view taken in summer.

This is the view from the far end, beyond the smaller pond.

I chose a calm sunny day with a temperature of 9℃ but I didn't see any bumblebees (negative findings are also important).  After our fairly cold winter and early spring I expect the bumblebees are having a lie-in as I haven't see one yet at home either.  There weren't many flowers around for any bees.  I did see plenty of coltsfoot and a few gorse bushes.  I am not very good at naming wild flowers so this will be an opportunity to learn more about them.

The alder trees were in flower but they are wind pollenated so they don't need bees.  These are the male catkins (with the female flowers above)

and these are the female flowers which will produce the cones later in the year.

Hazel trees were also in flower.  These are the catkins (again with the female flowers above)

and these are the tiny red female flowers.

You can see they have already picked up some wind-blown pollen.

A pair of mute swans has built a nest in the smaller pond but there are no eggs as yet.  Swans have nested here in previous years.  Last year the female was dead the first time I visited and the male was swimming around sadly but had gone by my next visit.

Here is the nest in the reeds, front left, taken on the iPhone as my camera had a telephoto lens.

There was pair of Canada geese on the larger pond.  They also have nested here before and a pair raised five goslings here last year.  I didn't see whether these two have yet built a nest.

Other birds I saw included buzzard, bullfinch, chaffinch, little grebe and long-tailed tit.

There was lots of frogspawn in the larger pond but no frogs.  I guess the frogs have been and gone and have nothing else to do for the rest of the year apart from eating and avoiding being eaten.

Assuming I get there and there is something to see I plan to post here each week until week 43.

What the sparrowhawk had for breakfast

Sparrowhawks, in common with owls and kingfishers, bring up pellets but I had never seen it happen before.  This time he was on top of the hedge, facing away from me.  I could see what was about to happen but because it was gloomy, and I was using a long lens with an aperture of f/6.3, I had set the shutter speed low and didn't have time to adjust it. This picture is a bit blurred but you can see the pellet about to emerge.

After he had gone I retrieved the pellet.  It was about 30mm long and had a few bits of bone sticking out of it.

This is recognisably the head of a tiny femur.  Having searched online I think it is a mammalian femur, probably that of a bank vole.  The femur of a blue tit looks rather different.  Isn't it amazing what you can find these days?

On this side was a line of bones, probably from a wing.

Once the pellet had dried out I teased it apart.  I had expected to find feathers but it consisted mainly of fur and contained several small bones and fragments of bone.

Here are several of the pieces of bone plus two rodent teeth(!).  The line of bones does look as though it is in the remains of a wing but the other bones could be from rodent or bird.

Here are the teeth, 6mm from end to end.  I think they are upper incisors, possibly from a bank vole, but they have slightly different curvatures and so are probably not both from the same animal.

A male sparrowhawk catches mainly small birds but will also take small mammals.  If it catches a bird it plucks its prey, removing a lot of feathers, and then eats almost everything else.  At the site of a bird kill I can find only feathers and I have watched him swallow the legs, including the feet and claws.  This pellet contains mostly fur and bones and the two teeth prove he is taking small mammals.

I have watched this bird staring at a bank vole below the bird feeder but I haven't seen him try to catch it although, come to think of it, I haven't seen the bank vole recently!

I read that sparrowhawks generally produce one pellet a day, usually first thing in the morning at the roost site.  If they feed well early in the day they may produce a second one in the afternoon.  This one came up at 10.30 am so I don't know if it was a delayed first pellet or an early second one.  So far I haven't found any other pellets, nor seen any others come up, but I'll keep looking.  

Sparrowhawk in sunshine

This was the first time I had seen the sparrowhawk in the sunshine.  The perch he normally sits on is outside a north-facing window and in winter is in permanent shade.  For a change of scenery he hopped up on top of the hedge and stayed there long enough for a few portraits.