Tag Archives: photography

Purse Web Spider: Britain’s Tarantula

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Meet our amazing mygalomorph, discover its life cycle and learn how to find it

The scarce Purse Web Spider (Atypus affinis) is rarely seen because it spends the majority of its life underground in a sock-shaped tube. In the UK it has the honour of being our only member of the mygalomorph family, which elsewhere includes tarantulas.

Male Purse Web Spider (Atypus affinis) on heathland. Dorset, UK.

Purse Web Spiders normally lead a solitary existence in a silk-lined burrow. The top portion of this tube extends above ground and is extremely well camouflaged with its surroundings, covered with bits of vegetation and debris. Most of the time this tube is completely sealed.

Camouflaged web of Purse Web Spider (Atypus affinis) on heathland. Surrey, UK.
Female Purse Web Spider (Atypus affinis) female in tube web. Sussex, UK.
Female Purse Web Spider (Atypus affinis) female in tube web. Sussex, UK.

When the Purse Web Spider’s prey makes contact with the exposed section of burrow the spider senses its vibrations and bites through the silk with its huge fangs. These distinctive downward-facing ‘chelicerae’ are shared with its larger, more exotic, arachnid ancestors. The fangs of more modern spiders cross over.

Male Purse Web Spider (Atypus affinis) on heathland. Dorset, UK.

In spring and autumn each year male Purse Web Spiders leave their burrows to go wandering in search of females. This is when you are most likely to find an adult spider. If successful in his quest he tears an entrance in her silk tube and, after mating, the pair will live here together for a while.

In early spring each year juvenile Purse Web Spiders exit the nest burrow and climb surrounding vegetation. They weave thick lines of silk to aid dispersal, and build tent-like structures around which they initially congregate.

Purse Web spiderlings (Atypus affinis) dispersing. Surrey, UK.
Purse Web spiderlings (Atypus affinis) create silk rigging. Surrey, UK.

Locating this silk rigging is a good indication that an adult’s burrow is nearby. Look out for it at the top of low gorse or heather on heathland in the south of England from mid-March. This species can also be found on chalk grassland.

Silk tents constructed by Purse Web spiderlings (Atypus affinis) on heathland. Surrey, UK.

In the aftermath of heath fires, discarded sections of Purse Web tubes become more visible. Heat damages the surface layer of camouflage, exposing brighter silk beneath.

Discarded Purse Web Spider (Atypus affinis) tube webs on burnt heathland. Surrey, UK.
Discarded Purse Web Spider (Atypus affinis) tube webs recovered from burnt heathland. Surrey, UK.

The Purse Web Spider is classified as Nationally Scarce and is Amber Listed. Although it remains widespread, the species has undergone substantial decline. However there is limited data available and so the British Arachnological Society (BAS) has launched a new Purse Web Spider Recording Scheme using iRecord. If you find one of these amazing creatures please be sure to let them know!

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White Admiral Watch: Rollo’s Story

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A tale in tweets following the life of Rollo, a White Admiral butterfly caterpillar, offspring of Camilla…

As Rollo slumbers a brief interlude follows…

https://twitter.com/domgreves/status/1308780313020170242

We return to the star of our show…

Rollo’s close neighbour catches a chill…

Spring returns to the wood…

White Admiral Watch pays tribute to Eric Carle, author of ‘The Very Hungry Caterpillar’…

https://twitter.com/domgreves/status/1401923300339683330

But not all is well…

The reason for Rollo’s delayed development becomes clear…

Search #WhiteAdmiralWatch on Twitter for more!

Puss Moth Metamorphosis

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I’ve photographed Puss Moth caterpillars (Cerura vinula) before, but this summer I wanted to follow them through all 5 stages, or ‘instars’, of their larval development.

Luckily I discovered a batch of recently laid puss moth eggs by searching the exact same aspen sapling chosen by another adult female the previous year.

6 June: Unhatched Ova

Puss moth eggs (Cerura vinula) on aspen
Cluster of Puss Moth eggs (Cerura vinula) on underside of aspen leaf

12 June: Hatched Ova

Hatched eggs of puss moth larvae (Cerura vinula)
Hatched eggs of Puss Moth larvae (Cerura vinula), showing signs of early feeding activity nearby.

12 June: 1st Instar

The ‘puss’ moths look a lot more cat-like at this early stage in their development I reckon.

First instar puss moth larva (Cerura vinula) on aspen leaf
1st instar Puss Moth larva (Cerura vinula) on aspen leaf. The distinctive tail-like appendages are already present.
1st instar puss moth siblings (Cerura vinula) feeding on aspen
1st instar Puss Moth siblings (Cerura vinula) feeding on aspen

15 June: 2nd Instar

I’d received a shock on my visit the previous day when I found the caterpillars frozen rigid in position, with their backs arched and tails in the air. They looked decidedly dead and I thought they must have been parasitised. Today, however, they were re-animated once more.

Puss moth siblings sharing the same aspen leaf
Puss Moth siblings sharing the same aspen leaf
Puss moth siblings on shared aspen leaf
The Puss Moth siblings were running out of space on their steadily consumed leaf and occasionally paused to whip their tails furiously at each other.
Second instar puss moth larva on aspen leaf
Close-up of 2nd instar Puss Moth. The jagged tentacles above the head are very prominent at this stage, unlike in the fully mature larva.

24 June: 3rd Instar

9 days later, after vanishing for several days, the two siblings had relocated further up the branch they originally hatched on. Neither was particularly active in the midday heat.

Third instar puss moth larva resting on silk pad
3rd instar Puss Moth larva resting on silk pad
Third instar puss moth larva resting on silk pad on aspen leaf
The distinctive saddle patterning of the puss moth caterpillar is much more visible by this stage.

28 June: 4th Instar

It lashed with rain on my next visit and the only visible puss moth was trying its hardest not to get pummeled off the leaf. Its silk pad lashed to the surface provides a firm anchor for feet to grasp.

4th instar puss moth on aspen leaf
4th instar Puss Moth clinging to wet aspen leaf. The hump on its back is now filling out.
4th instar puss moth larva
At this stage in its development the Puss Moth’s body has begun to envelop its head and the tentacles appear to have retracted.

9 July: 5th Instar

A further 11 days later I returned to find only one of the original 4 Puss Moth siblings remaining, now in its magnificent mature larval form.

Puss Moth larva (Cerura vinula) 5th instar in defensive posture.
Fifth instar puss moth larva detail showing extended pink flagellae
Detail showing extended pink flagellae. When threatened the Puss Moth extends these whip-like appendages from its tail end and waves them around crazily.

To be continued…

Soon after reaching this mature larval stage the Puss Moth stops eating and leaves in search of a safe place to pupate. Its transformation into the furry white adult moth can then begin. Despite much searching I couldn’t locate any pupae. Next time maybe!

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WPOTY 2014: Shortlisted

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Another year, another shortlisted image! This time in the ‘Invertebrates’ category:

Pond skaters

River sprites

Canon 600D + 100-400mm f/4.5-5.6L IS USM lens; 2 sec @ f/40; ISO 100

This is a long exposure image of pond skaters (Gerris sp.) in motion, taken in the shady bend of a local river one summer afternoon. Shortly after this frame was captured my tripod toppled over and the camera went for an expensive swim!

Unfortunately this year’s entry again failed to make the final cut. Congratulations to The Winners.

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Spring Wood Ant Antics

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Wood ant with heather seed
Wood ant (Formica rufa) foraging in early spring

The wood ant mounds among the pine trees were beginning to stir on my visit to the RSPB’s Arne reserve in Dorset recently.

Nests become active in early spring when worker ants begin to forage for food items and building materials to repair damage sustained over the winter months. Badgers, magpies, jays and other animals often raid wood ant nests for food.

Wood ant carrying twig
Wood ants are capable of carrying relatively heavy loads

Wood ant colonies can contain up to half a million individuals. On sunny days worker ants ‘sunbathe’ at the nest entrance to absorb heat and then re-enter the nest to release it – keeping it at a steady temperature. When the nest becomes too warm they open small vents to cool it down.

Wood ants at nest entrance
Sunbathing worker ants at nest entrance

The ants are particularly aggressive in springtime as they re-define their territories. Sometimes ants from weaker neighbouring colonies are recruited by force and carried back to the main colony.

Worker ant carrying another wood ant between nests

This species of wood ant is classified as Near Threatened (NT) in the IUCN Red List and classified in Great Britain as Local. Numbers seem to be increasing in the south of England but it has become locally extinct in parts of its former range in the north and east of England, the Midlands and north Wales.

Photographing ants is always a challenge because they’re small and they move very fast. It’s a good idea to keep your trousers tucked firmly into your socks when lying on the ground this close to a nest full of them! They will bite occasionally but can’t pierce skin. The formic acid they squirt in defence is too weak to harm humans.

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Harvest Mouse Survey

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Harvest mouse at night

Harvest mouse (Micromys minutus) captured on survey after dark

Last week I joined Surrey Wildlife Trust on a harvest mouse survey in wetland habitat beside the River Wey.

Harvest mice are tiny rodents 5cm in length. Their remarkable prehensile tails add an extra 6cm. They live in long tussocky grassland, reedbeds, hedgerows and around woodland edges, building a spherical nest of tightly woven grass, high up amongst the stems. We found several examples at this site:

Harvest mouse nest

Harvest mouse nests are woven from a mixture of living and cut grasses which provides excellent camouflage

Nests are the most obvious sign of harvest mouse activity since the animals are especially active around dawn and dusk and rarely spotted in the thick vegetation.

Dozens of rodent-friendly traps of different designs were set in the thick wetland reeds and grasses. Surrey Wildlife Trust staff and volunteers returned three times each day over the course of a week – at dawn, midday and dusk – to ensure that no trapped animals were left for any longer than necessary.

Rodent trap

Rodent trap baited with peanut butter, bird seed and dried blowfly larvae

After retrieval from the trap harvest mice are transferred to a transparent bag for weighing and sexing:

Harvest mouse in bag

Harvest mouse recovered from trap

Weighing harvest mouse

Harvest mice weigh only 5g on average

Once the details of each rodent have been recorded a small patch of fur is trimmed to identify any animals which are subsequently re-captured.

Harvest mouse being marked

Marking harvest mouse – a delicate operation!

The highest number of individuals captured was 12 one morning, making this the most abundant site for harvest mice in the county at present.

Harvest mouse in the hand

Harvest mice require very careful handling by trained experts

With thanks to Surrey Wildlife Trust staff and volunteers.

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Shortlisted: BWPA and WPOTY 2013

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Fox cub at night
Fox cub (Vulpes vulpes) in car headlights

Well it’s been another case of “nearly, not quite” in the furiously competitive world of wildlife photography this year…

WPOTY 2013

My image of a red fox cub in car headlights (above) was shortlisted in the Wildlife Photographer of the Year competition in the ‘Creative’ category, but progressed no further.

Driving home one night I encountered 3 cubs gamboling about in a narrow country lane without a care in the world. They were oblivious to the sound of car engines and headlights. I hope they survived to adulthood.

As any technically-fastidious wildlife photographer will tell you the term ‘creative’ is reserved for blurry, out-of-focus images, and this effort on my part made no attempt to challenge that prejudice!

BWPA 2013

In the domestic British Wildlife Photography Awards this year my image of a glow worm displaying against leaf litter was shortlisted in the ‘Hidden Britain’ category.

Glow worm
Glow worm (Lampyris noctiluca) displaying against leaf litter

Photographing glow worms is quite an adventure, and a frequently frustrating one, as my earlier blog post on the subject explains.

How short is ‘short’?

The BWPA shortlist comprises around 300 images we were informed, so the shortlist is not especially exclusive it seems! Winners have yet to be announced.

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Digger Wasp Hostage

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Sand digger wasp with caterpillar

The sand digger wasp (Ammophila sabulosa) paralyses its prey

We encountered another variety of sand digger wasp on the heath recently – this time Ammophila sabulosa, which uses caterpillars to feed its larvae.

Sand digger wasp with caterpillar prey

Sand digger wasps’ prey may be 10 times heavier than the wasp itself

Similarly to the spider-hunting wasp (Anoplius viaticus) it paralyses its victim with venom from its sting and buries it in a nest burrow. The caterpillar remains paralysed until the wasp larvae hatch out and eat it alive!

Sand digger wasp excavating nest burrow

Female sand digger wasps excavate a short burrow in sand

The entire nest cycle from site location, through excavation and provisioning, to finally sealing the burrow, takes 8-10 hours to complete.

Many wasps have ingenious parasitic strategies, as these earlier blog posts illustrate:

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The Magnificent Puss Moth

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Puss moth caterpillar

The puss moth caterpillar’s ‘eyes’ are only for display

A colleague working for Surrey Wildlife Trust kindly guided me to the location of this wonderful puss moth caterpillar (Cerura vinula) yesterday. A pair of them were contentedly grazing on aspen leaves.

Puss moth caterpillar grazing on aspen

Puss moth larvae feed on poplar, willow, or here on aspen

Colourful character

In adult form the furry grey and white moth flies at night between the months of May and July. The larval form looks much more exotic. The gawdy pink ring around its face gives the puss moth a very distinctive appearance.

Puss moth caterpillar

Head end of puss moth caterpillar

Self defence

If disturbed the puss moth caterpillar extends two whip-like appendages from its tail end and flails them around to deter attackers. It’s a bizarre and unexpected thing to witness.

Puss moth caterpillar tail

Puss moth caterpillar with extended ‘tails’

Puss moth caterpillar tail

‘Tail’ detail of puss moth larva

It also has the ability to squirt formic acid from its thorax if further provoked, but I didn’t try that!

Winter retreat

Shortly before pupation the caterpillar will change to a fetching shade of orange, and then again to purple.

It spins a cocoon of silk around itself and uses bits of tree bark as camouflage to stay hidden for the winter. The resulting cocoon is one of the strongest constructed by any UK moth.

I will have to return to see if I can find it in its various rainbow stages of development.

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Springwatched

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Spider hunting wasp with spider

Spider hunting wasp with paralysed arachnid prey

The team at BBC’s ‘Springwatch Unsprung’ programme used a sequence of my photos to illustrate the intriguing behaviour of the spider-hunting wasp, Anoplius viaticus.

This solitary wasp targets spiders, which it paralyses with venom and then hauls back to its subterranean nest burrow. Once wrestled inside the female wasp will lay its eggs on the spider’s body for its larvae to eat when they hatch.

Bug expert Nick Baker explained that this species stores its prey before excavating the burrow and so the unattended spider often becomes the victim of a tug-of-war between Anoplius viaticus and other opportunistic wasps and ants.

BBC Springwatch studio broadcast

Chris, Nick, Michaela, Martin and the Springwatch gang

Natural history superstar Mr. Chris Packham then related the curious fact that one of his first ever TV assignments was to film this invertebrate behaviour on nearby Studland Beach – this being made all the more awkward because it’s also frequented by enthusiastic naturists! Happily this particular site was a safe distance to the north on the peninsula. 🙂

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