Category Archives: Collections

Object of the Month – October

Dark stone with faint tracing of a fossil flower in two petal shapes

October’s Objects of the Month are pieces of fossilised plants.

Fossils can form in different ways depending on where they form and the type of plant or animal. Most fossils come from the hard parts of animals such as bones, teeth or shells. For plants, wood is the most common material to fossilise because it is quite hard, and takes longer to rot away than other parts.
Soft leaves and flowers need to be buried quickly in deep sediment like mud or volcanic ash where the low oxygen levels mean they won’t rot. Once underground, plant material can fossilise in different ways.

Compression

Dark stone with faint tracing of a fossil flower in two petal shapesThis flower is probably preserved by compression, like pressing and drying it in fine mud over millions of years. Heat and pressure deep underground turned the mud to stone and forced moisture and gases from the leaf at the same time.

The main ingredient in living plants is carbon, so a thin, black, carbon-rich film is all that’s left. In most fossils, new minerals replace the original material. But because this is a compression fossil, the carbon-rich film is the exact same carbon that was in the plant millions of years ago. Soft-bodied animals like squid can also be preserved like this.

Impression

Dark stone showing inpression of a fern leaf, with fronds alternating in an exaggerated sawtooth pattern

© SWM

This fern leaf, or frond, is preserved as an impression. When something soft is preserved by compression, the shape of it is also preserved as an impression, like pressing a leaf into soft mud or clay and then removing it.

This fossil is one part of a small rock nodule which was split in two to show the leaf – this part shows the impression of the frond. Because compression and impression fossils usually form together, the word ‘adpression’ describes both at the same time.

Petrification

Wedge of dark fossil wood, narrow at left. Lines of pale grey run top-bottom showing growth rings.

© SWM

Fossilised wood is often called ‘petrified’ wood, meaning wood ‘turned to stone’. It happens when the materials (cellulose and lignin) that make up the solid part of wood are replaced by minerals, turning it to stone.

Minerals dissolved in groundwater seeping through the sediment settle as solids in the microscopic cell walls of the wood as the cellulose and lignin slowly rot. This can create a perfect stone copy of the original structure of the wood.

See these objects up close in Curiosity Corner throughout October.

Object of the Month – February 2021

Water voles are probably best known from the character ‘Ratty’ from The Wind in the Willows. Recently described as “Britain’s fastest, declining mammal”, they are making a comeback thanks to careful wildlife management and the return of a locally extinct predator – the polecat.

Water vole © Saffron Walden Museum.

Water voles are about the same size as a brown rat, but with a furry, much shorter tail, and small ears. Today, they are a semi-aquatic mammal, relying heavily on streams and rivers for food and shelter – they use their teeth to dig burrows into steep banks to shelter and raise their young.

Do water voles need water?

But it wasn’t always this way. They don’t show any of the usual adaptations for a water-based mammal, such as webbed feet and a ‘keeled’ tail (flattened sideways but taller top-to-bottom), both of which make otters very strong swimmers.
In the 1500s, rewards for hunting ‘rats’ may actually have referred to ‘water voles’ that lived entirely on land. Their burrowing habits and herbivorous diet would have made them an agricultural pest, which would explain the rewards paid for hunting them. Modern water voles are always found on waterways, so any hunting must have succeeded in wiping out fully-terrestrial water voles.

A population vole-ercoaster

In the 1990s and early 2000s, the number of water voles in the UK plummeted, making them Britain’s fastest-declining mammal. Surveys of water vole territories in Essex showed that  81% of recent territories were still occupied in 1990, but by 2005, only 7.5% of territories were still occupied in certain areas.
Such a drastic decline couldn’t just be down to habitat loss, and they are resistant to pollution – water vole colonies live in the banks of streams which run from landfill sites along the Thames estuary, and on rubbish-choked streams near Rainham.

Studies by Essex Wildlife Trust showed that crashes in water vole numbers closely followed local increases in the number the invasive American mink. These animals are not native to the UK, and became established after escaping or being released from fur farms from the 1950s onwards. Mink will hunt water voles in their burrows and in water, and a female can destroy a water vole colony in one breeding season. The water vole’s usual predators only hunt on land, and are too big to fit in their burrows.

American mink. © Saffron Walden Museum.

Essex Wildlife Trust began work in 2007 to control mink numbers in key water vole strongholds, allowing water voles to recover, and spread. In 2012, more areas were put under mink control, and water vole colonies were relocated from sites destroyed by development along the Thames and M25. Surveys in 2013 showed that these colonies had survived and spread, with several new colonies established along the river Colne and its tributaries.

Ratty’s new best friends

Since 2000, wildlife surveys have found an ever-increasing number of polecats, a native predator which had been extinct in Essex for over 100 years. Polecats were hunted to near extinction across the UK by gamekeepers, who treated them as dangerous vermin, and they were also easily caught and killed in rabbit traps, which fell out of use in the 1950s. Polecats have probably spread into Essex from a targeted release in Hertfordshire in 1982-3.

Natural Sciences Officer, James Lumbard, with the skin of a recenltly-mounted polecat. The polecat was brought to the Museum after being found dead at the roadside. Image © Saffron Walden Museum.

Otter © Saffron Waledn Museum. This otter is on view in the Victorian Museum Workroom display when the Musuem is open.

Informal tracking and recording also suggests that the return of polecats may be helping water voles spread and recover more quickly, by reducing mink numbers. The same is true for otters, which are now returning to Essex, after being declared locally extinct in 1986. Both of these animals are native predators that rarely hunt water voles, but will compete with the American mink for food and territory, and are also big enough to hunt or kill mink. There are no studies to confirm it yet, but it could be very good news for water voles, and wildlife-lovers across Essex.

References

Are the otter and ​polecat combining to reduce mink numbers? East Anglian Daily Times, first published 31 March, 2019. Accessed 29.1.2021: https://www.eadt.co.uk/news/business/rise-in-polecats-and-otters-hit-mink-2562736

Mammals of Essex by John Dobson and Darren Tansley, 2014.

Object of the Month – October 2020

New Zealand Kiwi

We’ve been busy over the last few weeks moving the bird taxidermy from a temporary home back to their usual store. October’s object of the month is a mounted kiwi skin, probably of a little spotted kiwi (Apteryx owenii), the smallest of the five kiwi species.

A stuffed Little spotted kiwi sking, facing left, mounted on a 'naturalistic' base.

The little spotted kiwi in Saffron Walden Museum. © SWM

With strong, heavy legs and no wings, kiwis have evolved for life on the ground. They are nocturnal, dig burrows to nest in, and have stiff, hair-like outer feathers to withstand pushing through leaves and twigs. Unlike most birds they have keen hearing and a good sense of smell to help them find food, mostly earthworms and insects.

A page from a book with drawings showing the head, wing and strong feet of a kiwi.

Kiwis have ‘whiskers’ around their beak, stiff feathers and tiny wings, and strong feet for digging.
[Internet Archive Book Images / No restrictions]

Kiwi numbers have plummeted since Europeans arrived in New Zealand, bringing rats, stoats, pigs, cats, dogs, trophy hunting and habitat destruction. Kiwis grow and reproduce slowly and only thrive today on protected reserves, with intensive work to remove these threats. The indigenous Maori regard the kiwi as a taonga (treasure), and actively protect the birds across 230,000 hectares of land, about the same area as the national government’s Department of Conservation. Altogether, an area of land bigger than Essex is managed for kiwi conservation.

Coloured map of New Zealand showing distribution of kiwis at present day and before European colonisation.

Light green, current location of kiwis; Dark green, location of kiwis before European colonisation; Dark grey, kiwis never known here. [© New Zealand Department of Conservation]

Map with numbers and letters showing locations of Little spotted kiwi populations across New Zealand.

Little spotted kiwi reserves – Predator-free islands: 1, Hen Island; 2, Tiritiri Matangi; 3. Red Mercury Island; 4, Motuihe Island; 5, Kapiti Island; 6, Long Island; 7, Anchor Island; 8, Chalky Island
Mainland: A, Shakespear Open Sanctuary; B, Cape Sanctuary; C, Zealandia.
Michal Klajban / CC BY-SA 4.0

See the little spotted kiwi and find out more about kiwi species in our Object of the Month display when the museum re-opens soon.

More information
New Zealand Department of Conservation (DoC) –  Facts about kiwi: https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/kiwi/facts/
New Zealand DoC – Little Spotted Kiwi: https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/kiwi/little-spotted-kiwi/
New Zealand DoC – Kiwi: https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/kiwi/
Science Learning Hub – Conserving our native kiwi: https://www.sciencelearn.org.nz/resources/2784-conserving-our-native-kiwi
WWF New Zealand – Kiwi: https://www.wwf.org.nz/what_we_do/species/kiwi/

References

Internet Archive Book Images. ‘Features of kiwis’ Transactions and proceedings of the New Zealand Institute (1870). Internet Archive Book Images / No restrictions. Available from commons.wikimedia.org [Accessed 29.9.2020]

Michal Klajban. ‘Apteryx owenii – distribution map. CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0). Available from commons.wikimedia.org [Accessed 29.2.2020]

New Zealand Department of Conservation. Kiwi Recovery Plan Summary Document 2018-2028. New Zealand Government, 2018. Available from https://www.doc.govt.nz/nature/native-animals/birds/birds-a-z/kiwi/docs-work/ [Accessed 29.9.2020]

Black History Month (October) – Slavery Abolition Reticule

 

 

 

 

 

 

 

 

This silk reticule (bag) was made in the 1820s to support the campaign to abolish slavery. It was donated to the museum in 1927.

The reticule is a beautiful and very delicate object.  It is made from unlined pale pink silk with a drawstring at the top. On one side, the image of a seated enslaved man with his two children has been painted in black. On the reverse, there is a poem entitled ‘The Slaves’ Address to British Ladies’, which reads:

‘Mothers of the fair and brave
Heavy is the debt you owe
For the sufferings of the slave
Thro’ an age of pain and woe.

Shall your sons with freedom blest
Be the oppressors of our race
As I plead, each noble breast
Kindles at the foul disgrace.

Torn from Afric’s sunny plains
By your fathers’ cruelty
We have groaned in heavy chains
We have pined in misery.

But a brighter day is near
Blessings by your justice given
Faithful wives & children dear
And the hope of Joy in Heaven.

We shall bless your holy zeal
In our lisping girls & boys
For we have a heart to feel
All a parent’s anxious joys.

We shall see the harvests wave
And the sweets of science know
Freemen – at the name of Slave
Shall our souls indignant glow.

The reticule was made in the 1820s by a female campaign group, to raise funds and awareness for the anti-slavery movement. Although Britain officially ended its participation in the slave trade in 1807, slavery continued in the British Empire and in 1823, William Wilberforce formed the Anti-Slavery Society to campaign for the end of slavery in the colonies. Whilst women were allowed to join the society, they could not form part of its leadership, so a group of women in West Bromwich formed their own group, which was then referred to as the Ladies Society for the Relief of Negro Slaves (later called the Female Society for Birmingham). Other groups formed across the country shortly after and by 1831, there were 73 female organisations campaigning for the immediate and full abolition of slavery.

Many of these groups produced objects such as bags, jewellery, prints and pin cushions, decorated with abolitionist emblems, images and text. These items were sold or distributed as part of their campaigns. Silk bags and reticules like the one in our collection were filled with campaign pamphlets and newspaper cuttings and distributed to prominent people, including King George IV and Princess Victoria, as well as to other women’s anti-slavery societies.

It is very likely that this reticule was made by the Female Society for Birmingham. It is similar to reticules made by the society in the collections of the Victoria & Albert Museum, the Library of the Religious Society of Friends, and the Daughters of the American Revolution Museum in Washington DC. However, we have yet to find another example matching this particular design.

Conservation of the reticule

In 2017, the museum acquired funding to carry out conservation work on the reticule. The reticule was in very poor condition – the silk had faded and was stained, large areas of the silk had badly shattered and were coming loose, and the reticule could not be handled or displayed without causing further damage.    

With funding from the Daphne Bullard Award, the Saffron Walden Quaker Meeting and individuals in our local community, the museum was able to pay Poppy Singer, a textiles conservator, to carry out vital conservation work. Poppy cleaned and reshaped the reticule to its original shape, made an internal support bag and pad, adhered the fragmentary silk, and added very fine netting over the top to prevent future damage. Thanks to Poppy’s work, the reticule can now be carefully handled and displayed in the museum for short periods of time.

Object of the Month – October 2019

This case is arranged to show which butterflies live in the Saffron Walden area today (left), and which are extinct (right).

These butterflies died off mainly because of changing land use in the 19th & 20th centuries. Butterflies such as the Adonis blue (1) and chalk-hill blue (2) prefer large areas of chalk wildflower meadow, grazed by sheep and cattle. However, much of this land was converted to crop farming in the 1800s and these specialist insects died off. Other changes, such as the end of coppicing in woodlands, removed the open wooded habitat that butterflies such as the grizzled skipper (3) thrive in.

Species like the purple emperor (4) and white admiral (5) feed on the sugary waste products from aphids (honeydew). Pollution from coal burning may have contributed to these butterflies’ extinction as the toxins could dissolve into the honeydew on the leaf surface.

However, 2019 has been a very good year for some impressive larger butterflies too, with lots of painted ladies (6) arriving in Britain from the Mediterranean as they migrate north. Protected roadside verges in Uttlesford also provide good chalk grassland habitat for species such as the small copper (7).

There is also some very good news for three ‘extinct’ species (green boxes in main image). The purple emperor (4) returned to Uttlesford about two years ago and has been seen in Shadwell Wood and Rowney Wood, two local Essex Wildlife Trust nature reserves. The silver-washed fritillary (8) was first seen again about five years ago and is now known from Shadwell Wood, Rowney Wood and Hatfield Forest. The marbled white (9) has also been spotted at Harrison Sayer and Noakes Grove nature reserves and along some protected roadside verges over the last two years. The return of these three species in protected areas of countryside and special habitats show just how important effective conservation efforts are in supporting our native wildlife.

You can learn more about how humans have affected local environments and wildlife, for bad and for good, in the Take Away the Walls exhibition until 3 November.
Find out how you can help local wildlife groups on the Discovery Centre noticeboard next to the stick insects, and in the Take Away the Walls exhibition.

 

 

Object of the Month – June 2019

Did You Know?

The ‘cabbage white’ butterfly is actually two closely related species – the large white (Pieris brassicae) and the small white (Pieris rapae). Apart from the size difference, the large white has darker black wing spots, and a dark black band at the front of its wings. Both lay their eggs on cabbages in gardens, allotments and farms, as it is the preferred food of their caterpillars. The large white takes the outer leaves, while the small white prefers the soft inner leaves. The adult (imago) of both species often feeds on nectar from buddleia flowers.

Cabbage white butterflies “Insects Injurious to Vegetables”. SAFWM : 118007. © Saffron Walden Museum

The display has a male and female of each species, with the male at the top and female below. There is also a caterpillar of the large white butterfly, which is yellow and hairy, with black bumps on its skin. The small white’s caterpillar is pale green and hairless with a narrow yellow stripe on either side. The cabbage leaf in the box has some caterpillar feeding damage.

Caterpillar of the small white. CC BY-SA 3.0, Harald Süpfle.

Chrysalis of the small white. CC BY-SA 2.5, James Lindsey at Ecology of Commanster.

Life cycle

These butterflies have two ‘broods’ per year, and three in a good year. In the spring, butterflies which survived the winter as a chrysalis emerge as adults in April and May. They lay eggs in May and June (spring brood), which hatch into caterpillars in June and July. The caterpillars feed and grow quickly, and shed their skin 4 times as they grow. After about a month, the caterpillar finds a sheltered spot to transform into a butterfly in a process called metamorphosis. The caterpillar spins a pad of silk against the surface of its shelter, and sheds it skin again to reveal a hard skin (chrysalis), which has a small hook to keep it attached to the silk.

Adults emerge from the chrysalis about two weeks later, in July and August. They then lay eggs which develop into caterpillars through September and form chrysalises into October. The caterpillars go through a very slow metamorphosis to survive the winter, and emerge as adults the following April and May to start the process again.

Butterfly survival

On the right of the leaf are some cocoons and adults of a parasitic wasp which lays its eggs inside the caterpillars. After hatching, the wasp larvae feed on the caterpillar and eventually kill it, helping to control cabbage white numbers in a natural way. The adult wasp feeds on nectar.

Like many insects, these butterflies have declined in number recently. Currently, the large white and small white are not the focus of conservation efforts, but many other more specialist butterflies have declined severely or have gone extinct in Essex since 1900.
You can find out more about local butterflies in the Take Away the Walls exhibition at the Museum.

June’s Object of the Month was chosen by James Lumbard, Natural Sciences Officer.

Image credits

Pieris rapae caterpillar: James Lindsey at Ecology of Commanster [CC BY-SA 2.5 (https://creativecommons.org/licenses/by-sa/2.5)]. Accessed 11/06/2019.

Pieris rapae chrysalis: Harald Süpfle [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]. Accessed 11/06/2019

Parasitic wasp Cotesia glomerata: Copyright © Albert de Wilde – All rights reserved http://www.ahw.me/img/sluipwesp4mm_grootkoolwitje01b.html. Accessed 11/06/2019.

Featured Image – Cabbage whites “Insects Injurious to Vegetables” on display in the Museum © Saffron Walden Museum

 

The polecat comeback

Object of the Month – February 2019

The European polecat, Mustela putorius, was thought to be extinct in Essex since 1880 thanks to persecution from gamekeepers. The first modern sighting was in 1999 near Wendens Ambo and there are now numerous records from north-west Essex, though only from roadkill specimens.

A mounted polecat skin from 1842 and a polecat skull, also from the 1800s.

Continue reading

A bit behind the scenes

An update from James Lumbard, Natural Sciences Officer.

The Geology Gallery received a lot of attention in the run-up to the festive period thanks in no small part to the help provided by Cali, the latest addition to the natural sciences volunteer team. After a short training session in how to carefully clean specimens using a conservation vac and a paintbrush, we were away, and have already cleaned around half of the objects on display at the time of writing. It should be a fairly quick job to finish the rest of the objects in the ‘table-top’ display cases, leaving only a dozen or so in wall-mounted cases. This is part of regular ‘deep cleans’ that help care for museum objects, and will help us double-check and update the information we hold about each object. Many museums are also ‘Accredited’ which means that they uphold certain national standards of collection care, and this work contributes to Saffron Walden Museum maintaining its Accredited status year-on-year. Meanwhile, the photos we take can be used for everything from social media to encouraging researchers to visit the collection.

Fossil ammonite found in Saffron Walden. 150-200 million y.o.

At the start of December I visited the Essex Field Club’s (EFC) annual exhibition and social at Wat Tyler Country Park, near Basildon. The EFC is a volunteer-run society of amateurs and professionals who compile and look after a county-wide database of the wildlife and geology of Essex. The club’s secretary, Fiona Hutchings, very kindly introduced me to members from each specialty so I could speak to them about the natural sciences exhibition this summer, called Take Away the Walls. My plan is to hold a museum-based exhibition showcasing the wildlife of north-west Essex, and to run activities bringing together wildlife organisations and community groups across Uttlesford to help people enjoy the outdoors in new ways that will benefit their own health, and the health of the local environment. The exhibition and activities will really start to take shape behind the scenes soon, so keep your eyes peeled for more updates in the coming months.

Fossil bryozoan in flint. Tiny bryozoa live in coral-like colonies (above), but are much more complex internally.

At the end of this month I will be attending a short training seminar entitled ‘Finding Funds for Fossils, Ferns and Flamingos’, hosted by the Natural Sciences Collections Association (NatSCA) at the World Museum, Liverpool. NatSCA are a nationwide ‘subject-specialist network’ of museum professionals working in the natural sciences who have an active programme of meetings, training courses and conferences throughout the year. This particular event is all about how to successfully attract funding and support to care for and promote natural sciences collections in museums, and I look forward to putting my new-found knowledge into use to benefit the tens of thousands of natural sciences specimens at Saffron Walden Museum.

Object of the Month – June 2018

 

June’s Object of the Month is a silk reticule or bag, made in the 1820s to support the campaign to abolish slavery. The reticule was chosen as Object of the Month by Leah Mellors, Collections Officer (Human History). We featured the reticule on our blog last year, when we were raising money to fund vital conservation work. You can read all about the history of the reticule here

Our previous Collections Officer (Human History), Leah Mellors, acquired funding to carry out conservation work on the reticule, which was in very poor condition. The silk had faded and was badly stained, large sections of the silk had shattered and were coming loose and the reticule could not be handled or displayed without causing further damage. With funding from the Daphne Bullard Award, the Saffron Walden Quaker Meeting and individuals in our local community, the museum was able to pay a textiles conservator, Poppy Singer to carry out conservation work on the reticule. 

Poppy discovered that the bag had been folded over at the top and sewn down to cover some old damage, so she undid the stitching, cleaned and reshaped the reticule to its original shape. She made an internal support bag and pad to support the new shape of the reticule, adhered the fragmentary silk, and added very fine netting over the top to prevent future damage. Thanks to Poppy’s work, the reticule can now be carefully handled and displayed in the museum for short periods of time.  

Reticule before conservation

Reticule after conservation

You can see the reticule on display in the museum throughout June.