Tag Archives: British wildlife

Identification – cattle hock bone

Photo of the calcaneus.

Cattle right-side calcaneus (heel bone)

The calcaneus in humans is the heel bone, and is the first point of contact with the floor when we walk. However, cattle are ‘nail-walkers’ – walking on the very tips of their toes with the rest of the foot held off the ground. This means the first joint from the ground on the hind leg is the ankle (hock), not the knee, which is why it bends in the opposite direction to our knee. The knee is further up the leg, almost hidden by the leg muscles, while the hip is very high up, just below the base of the tail.

Diagrom to show position of hock in cattle leg

The hock bone (calcaneus) is shown by no. 32 (bottom right). 31 shows the ankle joint and 30 shows the knuckles of the toes. 27 shows the knee joint (bottom middle). Image credit: reference 1.

The bovine foot has 15 bones, grouped into 7 tarsals (talus, calcaneus, and five others), 2 metatarsals (running from the tarsals to thethe two toes). These correspond to the 3rd and 4th metatarsals in human feet The big toe has the first metatarsal). The cow has 6 phalanges (three in each toe).
For comparison, humans have 26 foot bones, comprising 7 tarsals, 5 metatarsals (one leading to each toe) and 14 phalanges (two for the big toe and three for every other toe).

Diagrams showing skeletons of the cattle and human foot.

15-21 are the ankle bones, 23 and 24 are the metatarsals, and 26-28 show the three phalanges in each toe. The same bones are labelled in the human foot on the right. Image credits: references 2 and 3.

(The image above actually shows the front leg of a cow, with the wrist and not the ankle bones, but the other bones are generally the same.)

Photo of the calcaneus.

The original bone I was asked to ID. © Saffron Walden Museum.

In life, this cattle calcaneus is from the right hock and has the smooth side faces outward to the right, as in the photo above. The shaft of the bone is then pointing up and back, toward the tail of the animal, to form the distinctive point of the hock in the cow’s leg (no. 32 in the first diagram). The top of the bone  is the attachment point for the large muscles of the lower leg. These are the gastrocnemius and soleus, (the ‘calf muscles’ in humans).

Some of the more fragile edges of this calcaneus are missing, but you can still see the main features.

This photo is pretty much a close-up of the photo above, from the bottom end. © Saffron Walden Museum.

In the photo, the letter A shows a smooth articular surface for the 3rd and 4th metatarsals, and B is one of the articular surfaces with the talus. C is a dome-shaped articular surface for the lateral malleolus, a bone on the outer edge of the hock.  The roughened depression (D) in the centre of the plate is called the tarsal sinus, and is mirrored by a similar area on the talus. This cavity houses blood vessels, fat, nerves, and a series of ligaments which hold the tarsal bones together.
The talar shelf (E), is at the near end of the shaft, and helps support the talus bone which sits above it. There is also a groove (F) for the tendon of the flexor digitorum lateralis muscle, which bends the toes.

 The calf muscles which attach to the top of the bone help straighten the leg when walking and running, while the length of the bone acts as a lever to amplify their effect and increase make the movement more efficient This is especially important in animals such as cattle, whose ancestors and wild relatives migrate across continents and run to escape predators.

 – James Lumbard, Natural Sciences Officer.

 

References

1. Domestic_animals;_ _history_and_description_of_the_horse,_mule,_cattle,_sheep,_swine,_poultry,_and_farm_dogs,_(1858)_(14598393827)
By Internet Archive Book Images – https://www.flickr.com/photos/internetarchivebookimages/14598393827/Source book page: https://archive.org/stream/domesticanimalsh00alle/domesticanimalsh00alle#page/n51/mode/1up, No restrictions, https://commons.wikimedia.org/w/index.php?curid=44520464

2. Cattle hock skeleton diagram © https://www.dcfirst.com/cow_skeletal_anatomy_poster.html Accessed 31.3.2020.

3. BruceBlaus. :Blausen.com staff (2014). “Medical gallery of Blausen Medical 201”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. / CC BY 3.0

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 – 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.

The parasitic wasp, now called Cotesia glomerata. © Albert de Wilde.

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.

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