May so far has been an unpredictable month weather-wise.
Weeks of unseasonal hot weather, interspersed with normal temperatures and
chilly winds.
But nature is still
getting on with things – we have blue tits nesting in their usual nest box
(they don’t seem to like the shiny new one), ‘our’ swallows have returned to
nest in the carport, and the house martins have been surveying a property in
our eaves (only surveying so far, no sign of nesting or laying).
There have been a couple of other welcome
events in the bird world – a cuckoo has been calling from the trees behind us
for a week or so but he seems a bit hoarse as though he’s been
over-cucking.
Hopefully a mate will have
survived the trip back from Africa so that he can give his syrinx (voice box) a
rest.
While we were sat in the garden
watching the sun go down one evening, we saw a barn owl carrying some prey
across the field at the back from the Pannel valley direction into the trees
behind the field.
 |
| Barn Owl (Norfolk) |
We’ve seen barn owls
in Pannel valley before, but never this far over.
The direction it was flying suggested that it
has a nest in the trees behind the houses on Pett Road.
I’d be interested to know if anybody else has
seen it.
We have also been fascinated by the activities of some other
nesters – solitary bees. These have
been making use of our solitary bee hotels and have been working hard for a
couple of weeks. The first thing to
attract our attention was a small swarm of male bees gathered round one of the
hotels. It was a very small swarm –
never more than half a dozen individuals, and they were waiting for the females
to enter or leave the bamboo tubes. They
may well have been out of luck though because any female nesting will already
have been mated and from what we could see, none of the females were interested
– entering and leaving the nests as quickly as possible.
 |
| Red Mason Bee Male. Note pale hairs on face and his passengers (mites) |
 |
| Red Mason Bee Female, and you can just see her horns |
The species of bee was the red mason bee (Osmia bicornis). It is called the red mason bee because of the
gingery hairs on their abdomen and because, if no bamboo tubes are available,
they will dig themselves a tube by excavating holes in soft mortar. In common with other solitary bees that nest
in this sort of hole, the female will go to the far end and build a pile of pollen
mixed with nectar. She will then lay an
egg on the sticky lump of pollen and seal up the hole, creating a cell in which
the egg can hatch safely. She will then
build another pile of pollen and nectar in front of the cell, lay an egg, and
so on, creating a series of cells along the tube until she runs out of
room. She may then go on to find another
tube or she may run out of eggs or energy and die. This means that there is no maternal contact
between the adult bee and her offspring that won’t emerge until next spring,
and everything that the offspring need to know about being a bee (including how
and when to emerge) has to be coded in their DNA.
When the eggs hatch into larvae, they will eat the pile of
pollen provided, spin a cocoon around themselves and go about the metamorphosis
business, going from larva to pupa, and finally emerging from their cocoon as
an adult bee. The adult bee then stays
in its cosy cell over winter, emerging when the weather warms up and there is
nectar and pollen available so that they can feed themselves up ready to found
the next generation.
You may have noticed the word
bicornis in the scientific name, which is latin for
two-horned.
This refers not to their
antenna but to a couple of prongs on the female’s face which are used to tamp
down the mud that they use to seal the holes.
The female doesn’t carry the pollen on her legs like other bees, but in
the pale hairs underneath her abdomen.
 |
| Ruby-tailed Wasp |
Ruby-tailed
wasps may also be seen near the nests which, though beautiful with their red
and green metallic colours, prey on mason bees.
It was fascinating to watch the female bee carrying mud in her mandibles
into the tubes and then, when the cell was sealed to come out, turn round, and
back into the tube to lay her egg – several minutes, or hours well spent.
