Tag Archives: featured object

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]

Object of the Month – June 2020

June’s Object of the Month celebrates Volunteers’ Week. These fossils have been cleaned and recorded by two dedicated geology volunteers, helping to audit the thousands of fossils held in the Museum’s stores. The project is suspended at the moment, but we all look forward to getting back together when times are better.

These fossils are from the Red Crag layers, which are the reason Walton-on-the-Naze is famous for marine fossils. The sandy Red Crag rocks and fossils were laid down in the late Pliocene and early Pleistocene epochs between 3.3 and 2.5 million years ago, when a warm, shallow sea and bay covered most of Essex. The fossils have stained red-brown over time due to iron-rich water washing through the sandy rock.

The first fossil is a species of whelk, Neptunea contraria, which is still alive today (extant, rather than extinct). This species has an unusual left-spiral shell, hence the word contraria in its scientific name. Almost all species with a coiled shell have a right-hand spiral.

Neptunea contraria

Cardita senilis

Cardita senilis is a species of bivalve, a group which also includes oysters, mussels and scallops. These molluscs have a flattened body protected by two shells or valves joined by a hinge. A bulge near the hinge, called the umbo, is the oldest part of a growing shell, and is at the centre of the growth rings that can sometimes be seen on the surface.

Spinucella tetragona is an extinct species of predatory sea snail, in a group known as murex snails or rock snails. This species’ shells are highly ridged, but other extant species (such as Chicoreus aculeatus) have exaggerated and complicated patterns of spines on their shells, which makes them very popular with shell collectors.

Chicoreus a

Spinucella tetragona

Chicoreus aculeatus

Oyster: Ostrea species

Later Pleistocene fossils from Essex, such as the oyster, don’t really ‘belong’ here at all. They were brought south or churned up from older rocks by glaciers during the Pleistocene Ice Age, which lasted from 2.5 Mya to 12,000 years ago. They appear in glacial drift deposits left behind as the glaciers grew and shrank. This fossil of Chicoreus aculea is actually from the Jurassic period (201-145 Million years ago).

All images © Saffron Walden Museum, except C. aculeatus: H. Zell – Own work, CC BY-SA 3.0

Identification – Limonite

Yellow limonite on brown goethite.

Limonite (pronounced “lime-on-ite”) is an iron ore similar to the more well-known iron oxides haematite and magnetite. It often forms as existing deposits of these other minerals react with water in an oxidation reaction, turning the iron oxide into iron oxide-hydroxide. This interrupts the regular crystal structure and opens up microscopic gaps that trap other water molecules in positions where they can’t chemically react and bond with the iron atoms. Water which forms part of the molecular structure of in this way is called ‘water of crystallisation’.

Yellow limonite on brown goethite.

Limonite can be ground up to produce the pigment yellow ochre, famous from prehistoric cave paintings. This sample from the Museums’ mineral collection has yellow limonite on brown goethite, another form of iron hydroxide.
Image: © Saffron Walden Museum.

Scientifically, limonite does not meet the criteria of a ‘true’ mineral, which must have a consistent chemical formula and molecular crystal structure. Because limonite forms as a replacement for several other minerals, this means that the crystal structure is not consistent. Variations in the original mineral, the compounds dissolved in the water and the environment where it forms, also mean the relative amounts of iron oxide, iron hydroxide and water of crystallisation are not constant either.

Four small, rounded pieces of limonite

These pieces of limonite were originally pieces of the gemstone garnet. Iron-rich water filtering through these stones replaced the original garnet mineral with limonite, keeping the shape.
Image: Eurico Zimbres FGEL/UERJ CC BY-SA 2.0 br (Wikimedia Commons)

Limonite may be any colour from a rich yellow to a dark brown, and was used historically to make the yellow ochre pigment which is still produced in this way in Cyprus. Despite this variation in colour, an easy way to distinguish it from haematite is the ‘streak test’. This can be used to separate many minerals which may appear similar to the eye, by rubbing the mineral along a piece of un-glazed white porcelain. Limonite will leave a yellow-to-brown streak, whereas haematite produces a red streak.

Two forms of haematite leave a rusty red streak on ceramic, central.

Two different forms of haematite both leaving a rust-red streak.
Image: KarlaPanchuk [CC BY-SA 4.0] (Wikimedia Commons)

Deep red botryoidal (grape-like) haematite.

This is an easily-recognised form of iron oxide, haematite. The rounded, bulbous form is described as ‘botryoidal’, meaning grape-like in Greek.
Image: © Saffron Walden Museum

 – James Lumbard, Natural Sciences Officer.

Identification – Ammonite in sandstone

One of the most interesting parts of working in museums is helping people discover something new (and I usually learn something new myself). A really important way for museums to do their job as a welcoming public source of information is by identifying mystery objects that you might find on a walk, on a seaside holiday or even in your garden or attic.
Anyone can bring in an item for us to identify, for free, and you should have an answer within a few weeks. It might look a bit like this:

Ammonite in sandstone

This piece of stone is a Jurassic fine-grained sandstone or sandy limestone, which may be from the Lias Group rock unit found on the Dorset coast, although it has a sandier appearance and rougher texture than the rocks usually found in this formation. If it is from the Dorset Lias formation, the rock is roughly 195 to 200 million years old, and the fossils it contains would be a species of Promicroceras ammonite, which are common along the Dorset coast.

Fossil of a Promicroceras ammonite.
Image: Ammojoe CC BY-SA 3.0 (Wikimedia Commons)

The bristleworm, Polydora ciliata. Image: Yale Peabody Museum of Natural History [CC0] (Wikimedia Commons)

 

 

 

 

 

 

The surface pattern of pores in the rock was made much more recently. They were probably made by a species of Polydora worm, probably Polydora ciliata. P. ciliata is a small, rock- or shell-boring worm which can grow up to 30mm (1 1/8 in.) long, and is also known as a bristleworm.

P. ciliata burrows in stone. Image: Rosser1954 CC BY-SA 3.0 (Wikimedia Commons)

Bristleworms are thought to burrow into rock or shell by scraping away at the surface using specialised bristles on the fifth segment of its body, although it may also secrete chemicals such as weak acid to help. It digs a U-shaped burrow, which appears on rocks as distinctive small slots or a ‘sunglasses’ shape.

 – James Lumbard, Natural Sciences Officer.

 

Object of the Month – February 2020

Snowy owl from front left angle. White breast plumage, with brown bars to sides and legs. Brown spotted plumage on wings. Mounted on a wooden post. Against a dark grey background.
Snowy owl from front left angle. White breast plumage, with brown bars to sides and legs. Brown spotted plumage on wings. Mounted on a wooden post. Against a dark grey background.

A female snowy owl in the Museum’s collections. Image: © Saffron Walden Museum.

Snowy Owl

A female snowy owl, Bubo scandiacus. Female snowy owls have spotted and striped plumage (above), while the male bird is almost pure white (below, left). Snowy owls live in the Arctic Circle where they hunt for food over tundra and upland moors. These impressive predators eat lemmings and other rodents, birds and rabbits, and only very rarely visit the far north of Britain. This mounted skin was donated to Saffron Walden Museum in 2003 for the Education collection. It has come out of the store for Museums at Night, exhibitions and teaching sessions.

A snowy owl from front angle. Pure white plumage of male, with a few dark spots visble on left wing. Against a pale background.

A male snowy owl. Image: Barry Kaufmann-Wright © Saffron Walden Museum.

An eagle owl from front left angle. Tawny under-plumage with patterns of dark brown and pale grey in bars and stripes. Vivid orange iris to eyes, and large horn-like feathers. Perched on a wooden post. Against a snowy backdrop.

An eagle owl. Image: Kamil. Corrections Piotr_J [CC BY-SA 3.0] (Wikimedia Commons)

Did you know?

All living things have a common name, like ‘snowy owl’, and a scientific name. The scientific name is a combination of two words which are only used for that species. Humans are Homo sapiens, and our extinct close relatives the Neanderthals are Homo neanderthalensis. We are different species in the same genus, Homo.
But scientific names can change. In 2004, the scientific name of the snowy owl was changed from Nyctea scandiaca to Bubo scandiacus, after years of research on their genetics and the shape of their bones. This showed that they were more closely related to horned owls and eagle owls (above, right), and should use the same genus name, Bubo.

You can see the snowy owl as Object of the Month until 29th February.

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.

 

 

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.

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Object of the Month -September 2018

September’s Object of the Month is a collection of fossilised teeth chosen by James Lumbard, Natural Sciences Officer.

These fossilised teeth come from the extinct fish Ptychodus (pronounced tie-co-duss) which lived across the Americas, Europe and Asia. They are closely related to modern sharks and rays, but may not have been direct ancestors. Some species grew up to 10 metres long, feeding on the large shellfish that existed during the Cretaceous period, 66–145 million years ago. Although they had similar diet and teeth to modern rays, they looked more like modern nurse sharks, which cruise the seabed for small fish and shellfish.

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Object of the Month – August 2018

Red squirrel - August object of the month

August’s Object of the Month is a red squirrel. The mammal was chosen as Object of the Month by Sarah Kenyon, Natural Sciences Officer.

This red squirrel was found dead at Saffron Walden, Essex in August 2003. It had been run over by a car in Landscape View. A member of the Uttlesford group of Essex Wildlife Trust gave it to Saffron Walden Museum to be preserved. The body was mounted, or stuffed, by a taxidermist. This red squirrel has russet red fur on its body and tail, with white fur on its chest and belly. Male and female squirrels look identical.

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