Garden snails Cornu aspersa

 

Garden snails Cornu aspersa mating.

One of the reasons garden snails are so successful is that they are hermaphrodite. In animals with separate sexes in equal numbers only half the population can produce eggs; in hermaphrodites like these snails every individual can lay eggs.

But they still need to mate, to exchange sperm, after a Cupid-like courtship ritual. Two individuals glide along side by side and fire calcareous love-darts into each-other, coated in a hormone which facilitates mating. and sperm exchange.

Titanic struggle: Garden spider versus bumblebee

 

We witnessed a titanic battle between an unfortunate bumblebee and a female garden spider Araneus diadematus that had spun her web on the flight path to Michaelmas daisies in the abbey garden, Hexham, Northumberland last week. For a while it looked like the frantically buzzing bee might escape, but then the spider’s poisonous fangs found a weak spot and the struggle subsided.

Then the spider suspended its prize on a thicker thread and spun it round and round with its feet, wrapping it a silken shroud paid out from the spinnerets on the tip of her abdomen.

A fraught wolf spider courtship

  A pair of wolf spiders courting in the garden, with the male (in the foreground) frantically signalling his amorous intentions to her with his palps, moving closer a millimetre at a time. She is ultra-aggressive and lunges at him, so he dashes for safety. During a long, hot afternoon they repeat the performance many times, but I never witness a successful mating. But it happens, because .....

..... a few days later, here is a female wolf spider basking in the sunshine on a rock, carrying a silken cocoon of eggs under the tip of her abdomen.

Dipper courtship

 I watched this pair of dippers courting along a stretch of the river Wear near Wolsingham in Weardale earlier this week. It's very difficult to tell the sexes apart but I'm pretty sure that's the male on the right, with his body stretched upwards. The female is fanning her tail and fluttering her wings. There's some brief wing fluttering going on in the second picture too. 

The distinctive white eyelid of  the bird that is blinking shows nicely.

Apart from this posturing, courtship seemed to mainly consist of the male pursuing the female up and down the river. Dippers always nest here, under an overhanging rock on the riverbank, and have a well-defined territory; rival pairs tend to confront each other at territorial boundaries early in the season, and usually turn back when they reach a rival's territory. They also sing with notes that are pitched at a level where they can be heard above the tumult of the river.

Sleeping beauty awakes

 This lovely peacock butterfly must have found its way into the house, unnoticed, during the very mild weather last October, and has been hibernating here ever since. It woke up late one evening a couple of weeks ago. After settling for a while on the television screen, it flew into the kitchen and began drinking water from a damp washing-up sponge. Central heating must have made it thirsty.

 

When it settled again it performed its well-known defensive trick of flicking its wings open and closed, creating a hissing sound when the rough hind edge of the forewing rubbed against the rough front edge of the hind wing.

It might not have survived the winter in the house, either because the spiders might have found it, or if had woken again and exhausted itself fluttering against the window. So, after acclimatising it to outdoor temperatures in the greenhouse for a couple of days, I let it crawl into a large terracotta flower pot, laid on its side in the shelter of the garden conifer hedge. If it wakes again before spring there are nectar-rich flowers of hellebores and pulmonarias in the garden for it to feed on.

Lapwing courtship and rivalry

You know that spring has really sprung when you witness this kind of bird behaviour.

There were three lapwings in this oilseed rape field - a female (left) and two males. The male in the right foreground had just finished a brief courtship flight display, then pursued the female through the plants on foot, until they both stopped. Then he turned and started pecking at the ground, in a perfunctory display of making a nest scrape, and displayed his rump. The second male, in the background here, had similar ideas. A recipe for trouble.

They both got airborne, to settle their rivalry with some aerial jousting. 

What followed was a lively display of close-quarters intimidation and some spectacular aerobatics, with a lot of noisy calls but no actual physical contact.

No idea how they judged who was the victor and who was the vanquished but .....

.... only one of them had the privilege of mating.

Fieldfare feeding frenzy

Thousands of fieldfares, arriving from Scandinavia and Russia, have passed through Weardale over the last few weeks, gorging themselves with this year's heavy crop of hawthorn berries.

They have a methodical way of stripping off the haws, at an incredibly rapid rate.

First, the lunge ....

.... and then the grab ....

.... followed by a sharp twist and a tug to pull it from its stalk ...

.... then a brief pause followed by little toss of the head to send the berries down into the gullet. 

This one downed seven in under a minute

More about their feeding preferences in the Guardian Country Diary today 

Baffled herring gulls

Some interesting behaviour from juveniles herring gulls.

These birds soon learn that the easiest way to break into bivalve mollusc shells, like mussels, is to carry them aloft and then drop them on a hard surface until they shatter.

This afternoon I watched these young birds on Union Quay in North Shields trying to do the same thing with large rubber washers. These must have come from fishing nets, that fishermen from the Fish Quay often dry and repair here.

First the birds grabbed the washers in their beaks and tried to whack them on the concrete then, when that didn't work .....

They flew up with them and dropped them on the quay, when they just bounced.

They gave up after about three attempts.

Tandem dragonflies

We spent a fascinating afternoon recently watching dragonfly behaviour at Ashes quarry at Stanhope in Weardale.

The most numerous dragonflies in the shallow, moss-edged pools there are common darters, Sympetrum striolatum. We watched them on their egg-laying flights, where the male tows the female around, attached by the tip of his abdomen to a point just behind her head.

Coupling up like this is the male's way of defending the female he has inseminated, preventing rival males from mating with her and displacing his sperm.

It's an unwieldy arrangement. At frequent intervals the male lowers his abdomen, forcing the female down to the water surface where she drops fertilised eggs from the tip of her abdomen.

That's an awkward manoeuvre, when the male momentarily hovers in this vertical position.

The males are fiercely defensive of their territory, often perching on a favourite stone or ....

... plant stem, ready to drive off rivals and pursue any passing female.

The second commonest dragonflies at this site are black darters Sympetrum danae. There seemed to be quite a lot of interspecific aggro - we watched several aerial battles between the two species.

These dragonflies land with their wings outstretched but ....

... finally come to rest with them in this swept-forward configuration.

Nursery web spider

Although some spiders have a fearsome reputation, there’s no denying that others have endearing qualities – and none more so than the nursery web spider Pisaura mirabilis, one of our larger native species, growing up to about an inch long. It's quite common in our region in grassy places, where it spends much of the time hunting insects on the ground or sunbathing on leaves. 

Its peculiar way of resting with its front two pairs of legs held close together, so that at first glance it appears to have only six rather than eight legs, makes it easily recognisable.

The one in the pictures below lives in the garden of my eldest son and his partner, near Blaydon.

 When the time for courtship arrives in early summer the male spider catches a fly, wraps it in silk and presents it as a gift to a potential mate. Sometimes, if he can’t catch a fly, he’ll present her with a gift-wrapped piece of debris instead but it seems that the size of his gift, rather than its quality, is the crucial factor in determining whether she’ll choose him as a mate.

It's the thought that counts ...... as any bloke will tell you if he's forgotten his wedding anniversary then bought his wife a last-minute bunch of flowers in a petrol station.

If she does accept his advances she'll eventually produce a ball of eggs wrapped in white silk that she carries in her jaws, slung under her body, until they are almost ready to hatch. The cocoon is so large that she is forced to walk around on tiptoe, to keep it clear of the ground.

What happens next is a remarkable example of spider maternal instinct. By the time that her eggs have matured the grasses have grown tall and she climbs to the top and binds several together with silk. Then in the space below she weaves a tent, deposits her eggs inside, nibbles through the cocoon so that the spiderlings can hatch and then finally seals them inside their silken nursery. She’ll stand guard while they grow large enough to take their first steps into the outside world. 

This particular spider is unusual in that it has recently lost its right front leg and is regenerating a new one - in the picture above it's the dark-coloured leg at the bottom of the picture.

You can see the new leg, almost black and at 8 o'clock, in this closer image. Spiders can regenerate lost limbs will they are still growing and still moulting their exoskeleton, but once they reach their final moult at maturity they can't replace lost legs.

  

Courtship amongst the Michaelmas daisies

This little beauty is Metellina segmentata and she's spun her rather untidy web between the developing flower heads of the Michaelmas daisies in our garden. Once the flowers open and start to attract insects she'll have a constant supply of prey in her snare.

And this is her consort, a male Metellina segmentata who also lurks on the edge of her web, keeping close watch on her and the web. When an insect is caught they both rush into the web but he grabs it first, wraps it in silk and presents it to her as a gift.

Yesterday I watched while he presented her with his gift, then while she was preoccupied with her meal he mated with her. He's a smooth operator.

Snipe

Thursday's Guardian Country Diary is about an encounter with snipe on Chapel Fell in Weardale.

Usually the first hint that there are snipe around comes from the sound of males during their territorial 'drumming' flights, when they fly a switchback course around their territory. During their dives single feathers on either side of the tail stick out (see photo above) and produce a strange reverbatory bleating sound.  As soon as the sound reaches the ground the snipe has already begun to climb again, so it's not easy to find the high-flying fast-moving bird against a clear blue sky from the drumming sound alone.

Click here to listen to the sound of a snipe drumming.

When this one had finished its display flight it landed on a fence post close to where I was standing and began its mating call - a weird metranomic tick-a, tick-a call that rises in volume then suddenly stops, restarting after a brief interval. The bird soon flew off, but .....

.... not very far, landing on this tall pipe and calling all over again. It seemed reluctant to leave and I discovered why ...

.... when the female casually walked out of a muddy patch of rushes just a few feet away from the wall that I was leaning on. The camouflage from her mottled plumage was exquisite and when she stood still it was easy to lose sight of her. I had time for just one quick picture before she sprang and zig-zagged away across the fell, towards her consort.

A memorable encounter.