Purseweb Spider Recording & Monitoring

In search of Purseweb Spiders (Atypus affinis)

BAS logoMale Purseweb Spider with permission of Graeme Lyons

In the latest status review of the spiders of Great Britain, published in 2017, the Purseweb Spider is classified as Nationally Scarce and is Amber Listed, meaning that although still reasonably widespread, the species has undergone substantial decline and is a candidate for targeted research and survey. However, the rate of decline is hard to measure from our limited data. Even if, as seems likely, we are losing colonies, this can be masked by discoveries at new sites.

We want people to look for Purseweb Spiders and record the outcome here, whether or not spiders or their tubewebs are found. For monitoring colonies, negative records are as important to us as positive records. We encourage you to submit photographs with your records to show what you saw and where you searched.

Known duration of Purseweb Spider colonies - graph

As of March 2019, the national Spider Recording Scheme had a total of 559 Purseweb Spider records from around 195 discrete colonies. The graph on the right show that of these colonies a mere 34 have records spanning ten years or more while, at the other extreme, 129 colonies are represented only by records from a single year. Of the 195 colonies, a remarkable 104 have no records since the turn of the 21st century.

What are we to make of the fact that Purseweb Spiders have not been seen during the past two decades at more than half of their known colonies? Are these colonies still extant? How many of them have been visited without finding evidence of Purseweb Spiders? We simply do not have the data to answer such questions.

This recording form - a joint project between the Biological Records Centre and the British Arachnological Society - is a tool that could help us fill that data gap. We encourage people to return to known colonies on a regular basis - preferably at least once a year - and record whether or not evidence of Purseweb Spiders (principally their tubewebs) is found.

Remember: negative records - i.e. cases where no tubewebs or spiders are found despite searching - are as important to this monitoring exercise as positive records. 

Where to look for Purseweb Spiders

In Britain, the Purseweb Spider’s stronghold is the south of England (see map). Away from here, in south-west and northern England, Wales and Scotland, there is a strong association with the coast. The spider has been recorded on the small offshore islands of Skokholm, Lundy and Puffin Island, off Anglesey, as well as farther afield on the Scillies and Channel Islands.

Purseweb Spiders have exacting habitat requirements that include good drainage, high solar radiation (typically, but not always, occurring on south-facing slopes) and a suitable substrate for their tubewebs.

Distribution of Purseweb Spiders in Britain

The British distribution is clearly linked to the presence of calcareous bedrock, but it also occurs on areas with heathy soils, as evident from its presence in the New Fores. It is typically found in old grasslands and other unimproved open habitats such as heathland.

For the most up to date distribution map of the Purseweb Spider in Britain, look at the distribution map on the British Arachnology Society's Spider Recording Scheme (SRS): http://srs.britishspiders.org.uk/portal.php/p/Summary/s/Atypus+affinis

Remember that records of spiders and/or tubewebs entered on this site will be shared with the SRS.

How to look for Purseweb Spiders

Purseweb Spiders themselves are rarely seen, but the tubewebs, once you learn to recognise them, are unmistakable. Finding a web is sufficient to record this species, and is almost as thrilling as seeing the spider itself! Counting the webs provides valuable evidence on the state of a colony, as does looking for webs but finding none.

Purseweb Spiders make their burrows in friable soils, avoiding those that are too compact, but also avoiding loose sandy and loessic soils which make it difficult to maintain a stable burrow. Most of its tubeweb lines this underground burrow and the exposed part above ground is disguised by particles of sand, soil or vegetation, meticulously placed in position by the spider from inside the tube.

The tubewebs of fully grown adults are typically around 10mm in diameter and between 15 and 25cm in length, although this is highly variable. Around 5–8cm of this length projects above the ground surface to form the aerial portion of the web – the part we look for when recording Purseweb Spiders.

The aerial portion of the tubeweb can lie flat along the ground, for example when concealed under a stone, hang downwards, such as when it is projecting from a bank, or be upright and anchored in place by silk, for instance up against the foot of a crag. In areas of calcareous or sandstone outcrops, tubewebs can often be behind vegetation at the base of exposed rock. By gently easing the vegetation away from the rock you may see webs, often anchored to the rock. It is also worth looking under stones lying on the ground - as long as these are relatively undisturbed.

Images of Purseweb Spider tubewebs


Site & visit details

Tell us about the site and other details of your visit. We ask for a grid reference, a site name and details of where you found, or searched for, tubewebs and/or spiders. If you searched over a very large area, consider breaking it down into a number of different sites and entering each separately.

Enter the date on which you found or searched for Purseweb spiders or their tubewebs.


Enter the name of the place where you found the spider.


Specify the grid reference of the place where you found the spider. You can click on the map to get this.


Your name. Enter as: lastname, firstname.


Indicate whether or not you found tubewebs and whether or not you were actively searching for them plus other details about your search and what you found.

Indicate whether or not you saw tubewebs at this location.

Please submit photographs of tubewebs if you took any (use controls under the map). These will help us verify your record.

Indicate the number of intact tubewebs you saw. If you saw many, just estimate as best you can. Intact tubewebs are those where the aerial portion is still attached to to underground portion (the aerial portion may, or may not, be 'inflated') or where the aerial portion is evidently under construction/reconstruction.

Indicate the number of detached tubewebs you saw. These are tubewebs where the aerial portion has been removed and is found lying on the ground with no evidence of the underground portion. You may also use this to record tubewebs that are more or less complete but which have been pulled out of the ground (e.g. by birds). Please note any interesting details in 'Additional information'.

Indicate the maximum number of tubewebs that occured within any 15x15 cm (6x6 inch) patch. This will help us measure the maximum density of webs you found. Include webs of all thicknesses - not just adults. For many colonies where density is quite low, the number will be 1.


Indiciate whether or not you spent time actively searching for tubewebs.

Photographs of where you searched are extremely useful. You can submit photos with this record (use controls under the map).

Indicate the number of people that were searching for tubewebs, including you.

Indicate how much time, in minutes, you (or your team) spent actively searching for webs. Please do *not* include time spent at the site when not actively searching, e.g. stopping for coffee. This is not 'person-minutes' so if there were two of you searching, for example, *do not* double the time you spent searching together.

Indicate how you were searching for spiders, e.g. 'looking around the base of anthills' or 'looking behind grass at the base of crags'. Include all the methods you employed. If you used several techniques, you can include an indication of which were the main ones used.

Please provide some detail about where you found pursewebs or spiders (or searched for them if none were found). Your grid reference the right area to be relocated, but this description will anyone monitoring the colony in the future to look in the same spots as you did. Please provide any information which could help pinpoint the spots you searched.


Tell us whether or not you saw Purseweb Spiders and, if so, other details about what you found.

Indicate whether or not you saw actual spiders, rather than pursewebs.

Please submit photographs of the spider(s) if you took any (use controls under the map). These will help us verify your record.

Indicate how many spiders you recognised as adult males.

Indicate how many spiders you recognised as adult females.

Indicate how many spiders you recognised as immatures (of either sex).

Indicate how many spiders you recognised as adults, but could not be certain of sex.

Indicate how many spiders you saw for which you were unsure of sex or maturity.

If you saw live spiders, please indicate what they were doing when you found them.

Additional information

Provide further information that will help us use your record most effectively.

Please provide any additional information of interest pertaining to tubewebs, Purseweb Spiders or the site.

Records of spiders & tubewebs entered here will be shared with the British Arachnological Society's Spider Recording Scheme (SRS), but to help us avoid supplying duplicate records, indicate here if you have submitted, or intend to submit, your record to the SRS independently.


Add photographs

Adding photographs brings an enormous amount of value to your records and helps us verify them. In particular you should aim to submit at least one photograph of a tubeweb or spider (if you saw either). You can add as many photographs as you like.