Nest box update

I read recently that blue tit chicks eat about 100 caterpillars each per day.  That means these are getting through up to 900 per day.  If each parent does half of the work it means each bringing a caterpillar every 2½ minutes for 16 hours, which is probably about what they are doing.  One parent habitually pauses on the guttering before flying in.

Here is the other with a beakful of what looks like chewed flies.

By the time they fledge the chicks will have eaten close to 20,000 caterpillars and there are another four boxes in the garden with blue tits (that I know of).  That means blue tits alone will have eaten 100,000 caterpillars in three weeks. And there are great tits, coal tits, tree sparrows and all sorts of other birds in the garden.  If it wasn't for them the world would be overrun by caterpillars.

Today is day 17 and the chicks are fairly well developed.  They are now sitting near the front of the box and are taking a great interest in the entrance (because that's where the food comes from!) but I haven't yet seen any climbing up to look out.

They hatched on 15 May


Here they are at 10 days of age.


Last night was the first time mother hasn't slept in with them, usually a prelude to fledging.  She probably thought she would get more rest in a bush somewhere.

In previous years the blue tit chicks have fledged at 18, 19 or 20 days so these will go in the next three days.  I will post an update when they do.

OtterCam in May

I have continued my monthly trail camera monitoring for otters.  One night a couple of weeks ago drew a blank for the first time this year, so I moved the cameras to a different position and was rewarded with more pictures.  Here are three frame grabs from the first video.

And the video.

The second camera was nearby.

The additional infrared LED was blinking - probably because the battery was running low.

In February and March there were three otters but last month and this I saw evidence of only one.  It may be that the two pups, who were nearly full grown in winter, have moved on to find their own territories.  Last night drew a blank as well so the present otter, if there is only one, certainly moves around.  With luck it is the female and she has, or is about to have, new pups.  I'll put the cameras out again in June to see if I can see what she is up to.

This snake needed a ladder

Yet another exciting and unexpected encounter.  I saw this tiny grass snake swimming in a sheer-sided moat in a garden in Northamptonshire.  It was swimming up and down and trying unsuccessfully to escape from the green water.

I managed to scoop it out without falling in and without injuring it so it kindly agreed to a few photos before being released into the grass where it belonged.

This little snake was only about 20-25 cm long so will have hatched last summer.  With luck (and if it doesn't fall in again) it will eventually reach a length of over a metre and live for up to 25 years.

The grass snakes in this country are Natrix helvetica, also known as Western European grass snakes or barred grass snakes.  They were recognised as a separate species only  two years ago after genetic analysis studies.  Prior to that they were considered to be a subspecies of Natrix natrix but that species is now confined to the east of the River Rhine in Germany.

A walk round the pond - Week 21

This week there were many mature male large red damselflies and lots of mating pairs.

I also saw several mature male common blue damselflies.

There were several azure damselflies, all in immature colouring.

A new species for the season was a blue-tailed damselfly.  This is an immature female of the form violacea.

After last week's sighting I saw another dingy skipper.

This one adopted a typical skipper posture with its wings folded on top of each other, something I haven't seen before in this species.

A new sighting for the site was a Mother Shipton moth.

This photo was taken close up with flash with my little Panasonic TZ90.

On the way out I came across an acrobatic mating pair of flies, the female of which seemed more intent on enjoying her lunch!  This is the Canon 7D with a 300mm lens.

And this is the TZ90 with flash from very close up.

So no dragonflies this week but I am optimistic for next week if the weather is OK.

Mystery egg

I made my first trip of the year to the Farne Islands last week.  I was with friends so I didn't take a big camera, which was liberating as I already have more than enough puffin photos, etc.  However, I did put the little Panasonic TZ90 in my pocket in case we saw anything unusual and it came in handy when we saw this.

The kittiwake was standing staring at the egg as if unsure what to do.

The mystery was explained by a National Trust warden.  The egg was laid by a razorbill in the kittiwake's nest in error. The razorbill wasn't allowed back to the egg and the standoff had been going on for two days.  By then the egg was probably non-viable but the kittiwake hadn't worked out how to get rid of it so it could lay its own (two) eggs.

Excitement in the bee house

This caught me by surprise.  The male red mason bees emerged a few weeks ago and the female cocoons have been biding their time.  Then suddenly three decided to emerge at once.  The bees behind had chewed their way out of their cocoons and broken down the mud walls between their cells but they then had to wait for their sister in front of them.

The bees are covered in parasitic mites of the genus Chaetodactylus, also known as pollen mites.  I had cleared out all the parasitised cells I could see in the winter but the mites can migrate within the bee house and enough had survived to cause this problem.  Obviously I can't see into all the nests built within raspberry and bamboo canes elsewhere in the bee house and they could be overwintering a lot of mites.

The first bee in the tunnel was taking her time chewing through her cocoon and the mud walls.

When she eventually made it to the end of the nest she was immediately pounced on by a waiting male.  He is quite old and faded and has lost most of his fur and so he looks shiny and black.  In this photo the second female has made it to the entrance of the nest.

The second female was also immediately accosted by a male and a second male tried to join in.  They fell into a plant pot below the bee house so I rescued them.  You can see how small they are.

As the third female approached the entrance two males entered before she could leave but there wasn't room to pass or turn round.

Eventually she also emerged and was grabbed by a male, and then a second.  This trio also fell into the plant pot and were rescued.

The unlucky second male in each trio then gave up and left.  I hope the females were all successfully mated and can get on with the work of producing the next generation.  The males' lives are almost over.

In search of the mountain bumblebee

A few days ago I joined a walk led by Shaun Hackett, a Northumberland National Park Ranger and bumblebee expert, to look for Bombus monticola, the mountain bumblebee (aka bilberry bumblebee).  It is confined to northern and western parts of Great Britain, mainly because of its preference for bilberry and willow flowers in spring and bilberry and heather later in the season.  We visited an area of bilberry close to Rothbury and were rewarded by seeing one B. monticola queen.  It was put in a pot for all to see close up although this didn't make for great photos.

We also saw all seven common bumblebee species including garden bumblebee (B. hortorum),

tree bumblebee (B. hypnorum),

red-tailed bumblebee (B. lapidarius),

white-tailed bumblebee (B. lucorum),

common carder bee (B. pascuorum),

early bumblebee (B. pratorum), a poor photo but included for completeness,

and buff-tailed bumblebee (B. terrestris), the only one I didn't get a photo of.

Another bumblebee was new to me, heath bumblebee (B. jonellus).

There were at least two species of cuckoo bumblebees although I am not sure which one this is, possibly B. sylvestris.

We saw two mining bees, Andrena fulva, the tawny mining bee,

and Andrena lapponica, the bilberry mining bee.

Other highlights were common heath moth (Ematurga atomaria)

and tiger beetle (Cicindella campestris).

After the walk I went to an area nearby with Louise, our local bee expert, and we saw several more B. monticola queens and two workers.  They were on the move and high in the trees which made photography difficult.

I didn't notice at the time but this one was being propositioned by an overambitious Andrena male.

This map from the BWARS website shows the distribution of B. monticola so I feel privileged  to have it within range of where I live.