Natural History

The year is 1812, and it is spring. Green, rolling hills are awakening with new life as the sun starts to warm, and the chill winds soften. Then there they would be, Great Bustards taking part in a mating lek. Proceedings would be heralded by a great sneeze, then a rasping, guttural croak. The proud males, moustaches fluffed, and wings flared to reveal the bright white feathers, strut back and forth to catch the attention of an adoring female. Standing at around 3 feet tall, these large birds, normally rather shy, would delight in the presence of spring and fill the air with their strange, croaking love song. Those passing the pastures of North Hertfordshire would possibly not have realised that these bizarre birds would, unfortunately, all too soon be gone from the countryside for the foreseeable future.

 

The Great Bustard on display in the Discovering North Herts gallery within North Hertfordshire Museum (Image courtesy of Matthew Platt)

 

The Great Bustard (Otis tarda) is believed to have been present in the UK from the early Holocene, around 11700 years ago. Several species make up the Otididae family, with the Great Bustard being the largest. In fact, it is the largest flying land bird and the worlds’ heaviest flying bird with males weighing up to 18kg. This weight means that these are not the quickest of birds. The name given to it by Pliny the Elder, avis tarda, means ‘slow bird’. However, this slowness does not mean that it is easy prey. They were known for being particularly wary of hunters, dispersing at the slightest sound, using their camouflaged feathers to hide them in the undergrowth. Suffolk fowlers created specialised ‘cribs’, small camouflaged hides on wheels pulled across fields via a pulley system. Concealed within, the fowlers would slowly approach flying birds, catching them unawares as they struck (Cocker and Mabey, Birds Britannica, 2005).

Reported to taste like a cross between a goose and a turkey, these huge birds were highly sought after for the dinner table. Whilst they were indeed difficult to catch, a period of intensive land enclosure in the 1840s meant that these large birds were facing a great reduction of the standard open spaces they require (Cocker and Mabey, Birds Britannica, 2005). As droves, the collective noun for Great Bustards, were placed under ever increasing agricultural pressures, these hunting efforts started to have a greater negative impact on their population numbers. Unfortunately, the Victorian passion for collecting acted as the final nail in the coffin. With its’ increasing scarcity, the price of eggs and skins rose, leading to an increased demand. There are various reports of the final bird in the UK but one of these last few was shot at Therfield Heath by 1832.

There have been various attempts to reintroduce these birds to the UK. The first attempt took place in Norfolk in 1900, followed by another in Porton Down, Wiltshire in the 1970s (Cocker and Mabey, Birds Britannica, 2005). Whilst both initial attempts failed, they did pave the way for the most recent introduction starting in 2004. Undertaken by the Great Bustard Group, with initial funding help from the RSPB, this project has been successful in re-establishing the Great Bustard in the UK on Salisbury Plain. Until 2013 the birds were sourced from the Russian Federation; eggs were taken from doomed nests and then incubated in an artificial system before being brought to the UK for release. However, in 2013 a decision was made to change the source population to eggs reared from Spanish stock. These eggs were sourced directly from successful nests, although early in the season to promote the production of a second clutch and further in situ populations. In order to prevent imprinting and keep natural human phobia in the chicks, they are fed by hand puppets designed to look like an adult Bustard and the rearing team also wear dehumanising suits prior to release. In 2014, 33 birds were released, and this stock showed a 50% survival rate over the first season, greater than both the previous Russian individuals and the expected survivability of a natural population. The UK population now stands at around 100 birds maintaining a self-sustaining population in Wiltshire.

There is definite promise that we may one day be able to see wild populations of these fantastic birds. And maybe that strange call will be the new indicator that spring is here once again.

Roll up! Roll up! See the mysterious platypus and much more!

Did you know that our museum collections are home to 100,000 natural history specimens from all over the world? Fossils, skeletons and stuffed animals aplenty. These amazing things were brought together over hundreds of years. Join us for a talk by our Assistant Curator, who will be shining the light on some of the strange and lesser known specimens from our Natural History Collections.

Get your explorer hats on and see some curiosities up close!

Join our Assistant Curator, Matt Platt for this fascinating talk.

Buy your tickets online or from the Reception Desk.

On Sunday morning, I led a walk with Angela Forster (from Hertfordshire County Council’s Countryside Management Service) around the Weston Hills, south of Baldock. Taking in parts of Baldock, Clothall and Weston, it goes through a variety of landscapes that help tell the story of the local geology, ecology and archaeology. It is one of the Countryside Management Service’s regular Walks and More events that aim to get people out into the county’s often under-appreciated rural areas both to learn about local wildlife and heritage and to help maintain an active lifestyle.

IMG_20160320_112022

Learning about geology in a dry valley near Old Wellbury Farm

The walk began in Baldock (in the car park at the rear of Tesco) and we went along South Road and Limekiln Lane and on to the footpath leading to the footbridge over the A505 Baldock Bypass. Here was a good place to stop and for me to tell people about the archaeological importance of Baldock. The line of the road south-east from the ancient town crosses the fields between this point and the A507, eventually falling into line with the footpath close to Old Wellbury Farm before climbing the hill to Clothall. Baldock is really two separate towns: an ancient settlement that was abandoned by AD 600 and the Knights Tempar’s ‘new town’ of the 1140s. The earlier settlement has strong claims to be Britain’s first town, developing in the fifty years or so before Julius Caesar’s invasions in 55 and 54 BC.

From the footbridge over the A505, we walked to Old Welbury Farm and turned right into a dry valley, along the long-distance Hertfordshire Way. This is a good place to discuss the geology of the area, with its underlying chalk bedrock formed 90 million years ago beneath a sub-tropical sea. A period of uplift pushed the tectonic plate above sea level until it sank again, to be covered in a layer of clay when it was at the bottom of a lagoon. Further uplift pushed it above sea-level once again and during the Anglian Glaciation, 475,000 to 424,000 years ago, North Hertfordshire was covered by an ice sheet. As the climate grew warmer, the meltwater wore valleys into the chalk bedrock that are today dry, although they look as if they should have streams in them. The glaciers also fractured the chalk, mixing it with surviving patches of clay, breaking flint nodules and depositing acidic sands in pipes and cracks in the rock. This makes for a very complex geology that is the bane of gardeners and archaeologists alike.

At the top of the hill, we turned right (north-west) off the Hertfordshire Way to cross the large field on a trackway leading towards the triangular woodland. Off to the right is a large crater that often has a pond in it, thanks to the underlying clay that impedes drainage. This is just one of several visible on the top of the hill, which were formed in August 1944 when two American B17 bombers from Parham airfield, near Framlingham, collided. They were on their way to Nazi shipyards at Brest in Brittany as part of the Allied invasion of Europe when the pilots realised that collision was inevitable so, to minimise the danger, they shed their bomb load. Part of the wreckage fell at Friend’s Green in Weston, killing a child and a woman evacuee.

IMG_20160320_114912.jpg

The henge at Weston Hills, seen as a slight hump in the centre of the field in the distance

Beyond the crater, it is just possible to make out a slight rise in the field behind the wire fence. This is better seen from the far end of the triangular wood at the end of the field, where its position at one side of the dry valley we had entered earlier can be appreciated. It is not an obvious monument in the landscape, but if you know where to look, it is visible as a slight earthwork. From here, the ditch that helped to define it is visible. Henges are believed to have been ritual monuments of the Late Neolithic and early Bronze Age (about 3100-1800 BC), but they are not the same things as stone circles, so don’t think of Stonehenge. Norton Community Archaeology Group excavated a similar monument in Letchworth Garden City between 2010 and 2013 and it is possible that this one in the Weston Hills was built as a replacement when the Norton Henge went out of use around 2200 BC.

From here, we crossed another field with more bomb craters either side, to the footbridge across the A505 Baldock bypass. Here, the edges of the cutting were seeded with chalk downland plants, providing an important ecological zone. This was one of the reasons for keeping the tunnel so short, the other being cost. The tunnel, though, reduces the visual impact of the cutting when seen from the east, helping to hide it in the landscape. At the top of the cutting, it is possible to see orange glacial sands filling glacial pipes and cracks in the chalk bedrock, visual evidence for the impact of the Pleistocene glaciation of this area.

The Weston Hills tunnel in 2013

The Weston Hills tunnel in 2013

From here, we descended into the Weston Hills nature reserve, designated as such in July 2012. It is actively managed by the Countryside Management Service and the Friends of Baldock Green Spaces, who keep the site tidy and help maintain the ecologically rich chalk downland landscape around Gibbet Hill. Here, a steep-sided spur is kept free from trees and scrub by grazing, as it would have been in the Middle Ages. It is home to an amazing diversity of wildlife, including the common spotted orchid and field scabious. The name Gibbet Hill is first recorded in the seventeenth century and presumably refers to a place of execution: a gibbet on top of the hill would have been a prominent and stark reminder of the potential fate of criminals at a time before the hills were planted with trees in the 1800s.

The other hillsides, which are largely hidden by woodland and scrub, have a number of ancient quarry scars, particularly to the east of Gibbet Hill. Although the name of Limekiln Lane shows why the chalk was being quarried in recent centuries, we also know that it was quarried in Roman times thanks to chemical analyses of mortar and plaster from buildings in the ancient town. More surprisingly, white tesserae (cubes of stone used in mosaic floors) from a villa in Leicestershire were also found to be from the Weston Hills. This suggests that the quarry owners were able to market their products over a wider area than just the local town. It also means that some of the quarry scars visible in the hillside are likely to be of Roman date; some of the more bowl-shaped scars could well be from then. There are also terraces on the hillside that lead to and from the quarries and many of these are probably also of Roman origin.

IMG_20160320_123828.jpg

Learning about the management of the Nature Reserve

At the north-east end of the reserve, back towards Limekiln Lane, management of the site is done by bringing longhorn cattle onto the site. These are docile and are not disturbed by dogs walked on the hills, unlike the sheep that graze Gibbet Hill (dogs should always be kept on a lead around sheep). By grazing in summer and autumn, they keep the development of scrub to a minimum. Thinning the woodland by hand also helps to allow some trees to grow taller while bringing sunlight down to ground level encourages the growth of woodland plants with the butterflies that feed on them. Birdlife is also abundant, with buzzards and tawny owls the main predators around the hills. Red kites are also becoming common around the Weston Hills and North Hertfordshire more generally, a real success for the conservation movement.

The Weston Hills walk is about 5.5 km (3.5 miles) and takes around two and a half hours at a gentle strolling pace. It can be muddy in places, but this is a reminder of the area’s complex geological history, and although some of the climbs are steep, it is not a difficult walk.