Wednesday, July 31, 2013

Eavesdropping on swallows

Thursday's Guardian Country Diary describes the wonderful views of nesting swallows that we had from the kitchen window of our rented holiday cottage, at Budle Bay near Bamburgh in Northumberland.

The birds were nesting in a small outhouse close to the cottage's kitchen window, so we had excellent views of their comings and goings from dawn 'til dusk. They'd already raised their first brood and were preparing for the second. When they landed they spent much of  their time either perched on the top of the outhouse door, or ........

...... or, less often, on the roof...
Their nest site was in the far left-hand corner of the building, so we could watch them hurtle in and out through the gap that had been left when the door had fallen off its rusted hinges. 

It seemed amazing that the returning birds could hurtle through that gap, passing from dazzling sunlight into Stygian gloom, and still land safely on the metal pipe in front of the nest, which was only about six feet from the entrance. Their braking capacity is even more impressive than their flight skills.

They spent a lot of time reinforcing their nest, especially around the entrance hole that must have been damaged during the raising of the first brood.

There was a coil of old rope on the outhouse roof, that provided material for repairing the mud nest......

...... along with grass straw.

This bird has succeeded in pulling off some rope fibres.

The female was usually the first to return and called to her mate .....

... searching the sky for him.

It's interesting that the bird can't tilt its head back and look upwards - it has to lean forward and then swivel its neck to look skywards when it's perched.

Usually the male bird would make a couple of noisy passes ....

then land ......

.... then they'd mate ...........

.........renewing their pair bond........

When they weren't flying, much of their day was spent preening ....

.... taking care of flight feathers ....

but mostly dealing with feather parasites.

It must be like an oven inside the nest, which will be infested with ticks and lice, and the female faced another two weeks of egg incubation inside a mud oven during a heatwave....

....but in the meantime there was time to just fly and feed.

Tuesday, July 30, 2013

Killer unmasked ....

A couple of weeks ago I posted some pictures of a drinker moth caterpillar, together with the larvae and pupae of the parasitic insect that killed it. The killer has emerged from the pupae and it looks like a tachinid fly of some kind.

You can see the prominent calypters at the base of the wings, which are a tachinid characteristic.

This individual has just emerged from its pupa and its wings have yet to expand.

Monday, July 29, 2013

St.John's Chapel, Weardale

It was only a little over a fortnight since we'd taken our regular circular walk around St.John's Chapel in Weardale but, when we visited again on Saturday, the intervening period of almost dawn-to-dusk sunshine had transformed the landscape. All the early summer flowers, like the wood cranesbill, had run to seed and perfect haymaking weather meant that all the meadows had been mown. 

Even though this was only July, it seemed as though the summer is slipping by and it felt, as they say around here, 'proper back-endish'.

Harebells and crested dog's tail grass beside Harthope burn

Marsh woundwort in flower beside a ditch at the bottom of Chapel Fell

The frothy blossom of meadowsweet, once used for flavouring mead (the name has nothing to do with meadows, it refers to mead).

Monkey flower Mimulus guttatus in the gravel beside the river Wear. Thirty years ago, when I first saw it on this spot, this alien plant from the western United States was much commoner along the river than it is now - it seems to have gone into decline.

Rushes flowering on the slopes of Chapel Fell. For much of the year these are dull plants but for a brief period, when they flower, they look very attractive in the sunlight (double-click for a clearer image)

Timothy Grass Phleum pratense, flowering in corners of meadows that the mower missed. Very similar to meadow foxtail Alopecurus pratensis, but that flowers in spring and this flowers in mid-summer.

A most heartening sight - one of twelve freshly emerged small tortoiseshells on creeping thistles, on the flanks of Chapel Fell. These butterflies seem to be doing very well around here this year - we had seven at once on the Inula flowers in our front garden this weekend.

Spot the fish: a trout, keeping station in the sunlit river below a waterfall, catching whatever the river delivers and only given away by its shadow - the fish's back is a very close match for the colour of the underlying rock.

Up on Chapel Fell the lapwings have finished nesting and are now forming flocks with their juveniles.

Sunday, July 28, 2013

Common helleborine

Broad-leaved helleborine Epipactis helleborine is our commonest helleborine species but it's muted colours make it easy to overlook when it's growing amongst tall vegetation. This fine specimen was growing on a bank amongst long grasses on the outskirts of Durham city.

This orchid seems to be spreading quite nicely around Durham city - it's now well-established in numerous places in Durham University Botanic Garden where the gardeners carefully mow around it. I've also seen it in the grounds of several colleges, but there the plant is often less fortunate and tends to be mown when the grass is cut, after the daffodil foliage withers, and never reaches flowering size.

Saturday, July 27, 2013

Red Mites

These tiny red acarine mites, just a couple of millimetres in diameter, seem to thrive in this hot weather, racing over sunlit surfaces and only pausing to pick up food morsels. 

The even hunt on the lids of the black compost bins in the garden, which are almost too hot to touch on the sunniest days. 

Friday, July 26, 2013

Welcome visitors

Three baby hedgehogs have been snuffling around the undergrowth in our garden at dusk recently, and spending the days sleeping in the flower borders. I suspect that their mother must have nested in the accumulation of dead leaves under the beech hedge. 

Hedgehog numbers seem to have plummeted around here over the last couple of years, judging by the very low number of road casualties that I've seen.

Thursday, July 25, 2013

A native pollinator explores an alien flower

These sand dunes, between Alnmouth and Warkworth, have long been a favourite destination for botanists. The hollows are filled with wild thyme, biting stonecrop, bird's foot trefoil, viper's bugloss and spotted, twayblade and pyramidal orchids, to name but a few. This is also one of the only places in our region where sea pea has been recorded - which I've searched for here but never found. But when we were there a couple of weeks ago, we did come across an interesting alien.

Our visit coincided with a mass emergence of five-spot burnet moths and when they were not busy producing the next generation they were swarming all over the flowers, notably ...

...... this garden iris, possibly Iris sibirica which someone must have planted here. Bearded iris, I. germanica, is recorded as an introduced alien here in George Swan's Flora of Northumberland, but this clearly isn't a bearded iris, which has a beard of hairs in the 'gullet' of the flower . It must have been here for quite a while and bore a couple of large, empty seed capsules from last year's flowers, so might seed itself around and establish a population. 

What was mos striking about the plant was what a magnet it was for the five-spot burnets. The plant is a bit of a beacon, being the tallest brightly-coloured object in the dunes, and they homed in on it from all around.

When they landed none of the moths seemed to have any idea how to feed on the plant's nectar, but they quite quickly worked out how to reach it.

Usually, like this one and the one below, they began by probing the petal surface with their proboscis ....


.... then, when they found that unrewarding, moved down to the petal base to reach the nectar.....

.... but after a while most seemed to align themselves with the yellow flash in the middle of the fall petal, which led them into the legitimate route to the nectar, used by the plant's natural pollinators which are bees.

This involved forcing their way into the confines of the tube between the fall petal and the standard petal above, which has the stamen concealed underneath it, so the visitor is forced to pick up pollen on its back.

Once the flower markings had pointed the burnet moth visitor in the right direction it invariably crawled all the way in - and became stuck, unable to reverse out. After a pause and a bit of a struggle the moths finally managed to force their way out through the narrow gap between fall and standard petals - and were always carrying iris pollen when they left.

The interesting aspect of this is that it's an example of a native pollinating insect responding correctly to the floral advertisements of an introduced, non-native flower species that is adapted to bee pollination and that the moths would not have encountered before or co-evolved with. The plants that the moths normally pollinate on the dunes have numerous small flowers with easily-accessible nectar. It's clear that these moths are pollinating the iris and most likely contributing to its seed set.