Back to the wall of bees

I first wrote about the bees in this wall seven years ago.  It is an old cob wall near the church in Nether Heyford, Northamptonshire, one of several similar walls in the village.  The wall is hundreds of years old and is home to hundreds or even thousands of bees.  They are all solitary bees and most are either hairy-footed flower bees (Anthophora plumipes), common mourning cuckoo bees (Melecta albifrons), or red mason bees (Osmia bicornis). When I visited a month ago most of the bees I saw were male hairy-footed flower bees, hanging about in the hope of finding a freshly emerged female.  When I returned last weekend all the males had gone (having mated and died) and the females were busy provisioning their nests in the holes in the wall.

This one is just leaving for a foraging trip.

Here is a female returning with pollen and nectar.

The bees remember roughly where their nests are but sometimes take a few moments to locate the right hole.  Their navigation might be put off by me standing in the way.

Each nest has several cells, each containing an egg and enough pollen and nectar to sustain the growing larva.  These two bees were shovelling loose material back into their nests, presumably to seal in a cell they had provisioned and completed.

Aggregations of hairy-footed flower bees attract a kleptoparasitic cuckoo bee, Melecta albifrons.  The females of this bee loiter near the nest entrances, hoping to sneak in and lay their own eggs while the owners are away.

The male bees hanging around the wall this time were red mason bees (Osmia bicornis).  Their flight season is slightly later so most of the females were yet to emerge.

Here is a short video to give a flavour of what was going on.  Three species are visible, female hairy-footed flower bees (round and black), common mourning cuckoo bees (thinner and dark), and male red mason bees (small and red).

A few yards away in the churchyard I saw Melecta albifrons,

ashy mining bees (Andrena cineraria),

and tawny mining bees (Andrena fulva).

Mining bees have a similar lifestyle to flower bees and mason bees but they dig their nests in the ground.  They also attract their own specific cuckoo bees.

Back at the wall I found a spider that had just captured a cuckoo bee.  The spider was also hiding in one of the holes and had built webs across several of the others.  It was in the process of wrapping the bee, which was still alive, and then appeared to bite it, presumably with a venomous or paralysing bite.

I think this is probably a female noble false widow (Steatoba nobilis).  This spider first appeared in Devon 150 years ago, having been imported from the Canary Islands in a consignment of bananas, and is now widespread across the southern half of the UK.  For a description of the false widow spider and some amazing photos see Jason Steel's website.

Spring is later up here in the north so I hoped some of the local male A. plumipes would still be around.  Yesterday I was in Morpeth, 10 miles north of here and 230 miles north of my mother's village, and there they were.  I don't know where the nest site is in Morpeth but I saw several male bees sipping nectar in the town centre.

There were more females on the wing, this one showing how her proboscis splits to show the tongue and folds away underneath her "chin" when not needed.

The Morpeth hairy-footed flower bees were first recorded last year and are spreading south through Northumberland, presumably from the original outlier population in the Alnwick Garden.  I hope it won't be long before they reach Newcastle.

Out with the old and in with the new

Mrs Badger is a very tidy animal and has been busy spring cleaning.  I think this is the mother of two cubs I videoed coming out of the sett for the first time two years ago.  I set up the camera again in the hope of a repeat but all I have seen so far is housework.  On this evening she spent six minutes making six trips clearing out the old bedding and another 22 minutes and seven trips replacing it with fresh stuff.  So we don't have to watch it all in real time I have speeded up the action.

I'll keep the camera in place for a while in case new cubs make an appearance.

WaterShrewCam

A new target for the trail camera and this one is tricky!  It started when I noticed a series of apparent false triggers on one of the otter cameras.  When I looked closely there was a tiny water shrew in the corner of the video.

Looking through the otter-less clips I found several with the tiny shrew swimming upstream at amazing speed as it returned from hunting forays in the pool below the culvert.  This is a montage of five episodes, the first two in a hailstorm.

Since then I have repositioned the camera a few times to get closer and better pictures.  This was the first attempt.

Then I removed the scrap of wood and the root to get a closer view.

Here is the shrew with prey, first a freshwater shrimp and then a caddis fly larva.  For the second one I have added a zoomed in view at 1/10 speed so we get a better view of the action.

Water shrews are mainly active at night, hunting underwater in complete darkness.  Like other shrews they have to eat very frequently so they are sometimes seen in daylight.  Paradoxically the camera found it more difficult to see the shrew in the day because of the high contrast between sunlit water and deep shadow under the bank.  Here is a little montage of daytime action.  This gives the best view of what I presume is soil excavated from a nest chamber in the bank, where the shrew disappears to at the end.

The water shrew (Neomys fodiens) is the largest of our three native shrews but is still small, slightly smaller than a wood mouse.  As you can see above it is an excellent swimmer and hunts for aquatic insect larvae, crustaceans and small fish under water.  It is very buoyant and pops to the surface as soon as it stops swimming.  It has a dense waterproof coat and hairy feet and toes which help it to swim.  Its nest is in a bank close to water with multiple entrances, some at or below the waterline and others higher to protect against flooding.  I found two small holes 30-50cm higher up the bank above where these videos were recorded.

You can read a fascinating paper investigating the sensory abilities of the closely related northern water shrew (Sorex palustris), including how it can smell underwater, here.

A few years ago I saw a water shrew in my garden on a trail camera.   Despite the video evidence I couldn't convince people what it was until I caught it in a Longworth trap and took photos to prove the ID - then they believed me!  Water shrews are occasionally found away from water, perhaps as they disperse from one site to another.

This one needs to be careful for there is another predatory aquatic mammal about, one 500 times heavier* and for whom the shrew would be just a mouthful.

* Tyrannosaurus rex weighed over 5,000 kg, so 500 times larger than an otter.  You can watch a brief David Attenborough video here, in which he talks about the water shrew and how it is probably similar to the earliest mammals that took advantage of the dinosaurs' extinction.

Better late than never

I had almost given up on a nest in the camera box this year.  Then three days ago I saw a single strand of grass that hadn't been there the day before.  And two days ago a blue tit arrived.

As well as having a good look around it did the wing-spread dance that is used to place nest material and form the nest cup - even though there was only one strand of grass to work with!  I hope this is good news and is a sign that blue tits will move in.  I have seen them jumping around in the bushes opposite so they are certainly interested.  Here is a short video of the bird's visit.

My nest box was put up in 2009 and was occupied every year from 2009-2019, once by great tits, once by tree sparrows and nine times by blue tits.  In the nine years blue tits produced 54 eggs (0-11 per year) of which 53 hatched and all 53 fledged.  For the last two years the box has been unused with no attempt at nest building.  I am not sure why as there have been plenty of blue tit nests in other boxes.

This is a late start but the weather has been miserable.  Previously the latest start for building was 04 April.  The date of the first egg has ranged from 23 April to 10 May with a later date strongly associated with a smaller clutch, probably weather-related.

Data from the BTO BirdTrends show that nationally blue tits are laying their first egg about a week earlier than 50-odd years ago, probably related to climate change.  There is wide year-to-year variation, again probably weather-related.  (Day 110 is 9th April.). The first egg has been laid here between day 120 and day 137, so later than the nation average as we are farther north.

Over the same period the BTO data show a reduction in clutch size, brood size and number of fledglings.

Despite this blue tits are doing well with an increase in adult survival.

If the blue tits make a go of it this year I'll put regular updates on another nestbox camera page for the blog, accessed via a tab at the top of this home page, as I did for 2015-2019.

Hunting for frogs on OtterCam

This has been a frustrating exercise.  In March 2020 the trail camera recorded an otter eating frogs in the culvert for the first time.  In March 2021 it did so again so I set up a second camera to record it hunting but, perhaps because I was too late, I didn't see it catching anything.

This year, forewarned, I had cameras in position at the end of February.  The sequence I was hoping for was an otter hunting underwater for a frog, catching it, carrying it into the culvert and eating it in front of the camera.  Unfortunately the otter hasn't read the script.

This is as far as I got.  Here you can see the otter catches a frog, takes it only just into the culvert but then sits just below the second camera so we can only see the top of its head.

Another episode was similar.  This time the otter sat with its back to the camera.

On the one occasion the otter sat in the right place the culvert camera was slow to react and the first camera missed it altogether.

Here is a little montage of clips of the otter hunting.

Surprisingly the camera also recorded a frog.  I am surprised because the frog is coldblooded and I didn't know it would trigger the camera.  It wasn't moving quickly so I have speeded up the video x 4.

I have cunning plan for next year.  When there is no water flow this summer I shall crawl up the pipe and fit a couple of camera mounts to the roof.  Then next spring I can return (wearing waders) and fit a camera looking back towards the downstream end so if the otter sits there the camera can see it.  We'll see if that works.