How it Works, by Karen Wrigglesworth

The free-flight aviary at Virginia Lake is a popular attraction for many visitors.  It is another example of the many gifts that have been presented to the city by forward-thinking philanthropists and volunteers.

The present aviary was officially opened on Sunday 12 August 1979, along with the dovecote which stands nearby.

The concept of a free-flight design, which allows visitors up-close walk-through access to the birds, was a novel idea in the late-1970s.  The Wanganui aviary proposal is attributed largely to Barrie Harvey of the Round Table.  Considerable effort was made to come up with a suitable, workable design solution, and even then the aviary was not straightforward to construct.

Built largely as a volunteer project by the Wanganui Round Table organisation over a series of weekend ‘working bees’, the new aviary took two to three years to complete.  The major difficulty encountered was finding a workable technique to fix the irregular shapes of wire mesh together, and to adequately support the aviary’s framework.  Eventually, extensive welding of the wire mesh joints saw success achieved.

Rotating mesh doors were designed and fitted at either end to keep the birds enclosed.  Security cameras, and an aviary extension, came about two decades later.

The Wanganui Round Table Group was awarded the Community Service Rosebowl in late 1979 for its contribution towards the new aviary at Virginia Lake.

Material costs for the 1979 project amounted to $11,000 – a large part of which was raised through public donations and grants from local organisations, including the council.

Similar ‘free-flight’ cages are now installed at various parks and wildlife facilities worldwide, and house both birds and animals.  Structures such as the free-flight enclosures at Otorohanga and Brooklands Zoo, New Plymouth provide a unique experience for visitors, and an enhanced home for wildlife that is as ‘natural’ as possible for an exhibit enclosure.  The free-flight aviary at Hamilton Zoo is the second largest enclosure of this kind in the world.

The present Virginia Lake aviary is not the first to have been erected at the reserve.  Two earlier aviaries have entertained visitors, with the earliest dating back to 1942.

Many readers will remember the aviary that predated the current one – a five-section facility similar to aviaries still in use at the Victoria Esplanade Park in Palmerston North, among other places.  This aviary stood between the Winter Gardens and the carpark, and when opened in 1960 was home to 60 birds.  Council records contain many letters of thanks to local residents for donations of aviary birds, including finches, canaries and parakeets.  There was even for many years a kea amongst the collection – before rules for keeping native birds changed.

The first Virginia Lake aviary was a gift from Mr and Mrs AW Larsen of Foster’s Hotel (now Stellar’s) in 1942, as an attraction for children to complement the recently completed Centennial Memorial Winter Gardens, which had been opened in 1940.  Mr and Mrs Larsen owned “a very nice aviary of original design” together with twelve birds, which they were unable to take with them when they left the city that July.

The only stipulation the Larsens made was that the birds must not be sold or given away to be put in small cages.

The Mayor and council at the time gratefully accepted the gift, and arranged for the structure to be moved onto a concrete base at the lake reserve.

Keeping caged birds and animals is a very old tradition in many cultures.  Maori were known to keep tui in cages and to teach them to ‘talk’, and Victorian England had a well-known fascination with zoology and natural things.

The bird cage at Rotterdam Zoo was the largest zoo aviary when built in 1880, though the  Flight Cage built for the Louisiana Purchase Exposition in Saint Louis in 1904 was larger (at 70m long, 25m wide, and 15m high).  It remains one of the largest free-flight aviaries in the world today.

The immersion zoo exhibit, similar to a walk-through aviary in concept, was first developed by Carl Hagenbeck in 1907, and was revived and expanded following the opening of a ground-breaking gorilla exhibit at the Seattle Zoo in 1975.  Carl Hagenbeck (1844-1913) began collecting animals at 14, and later exhibited humans (including Nubians, Samoans and Inuits) as well as animals in ‘natural’ settings in his zoos.  His ‘naturalistic exhibit’ ideas – though fortunately not his taste for human exhibits – is now common practice at zoos worldwide.

Special thanks to Gillian at the Council Archives for hunting out useful records for this piece, and wikipedia.

Karen Wrigglesworth is a local engineer and writer.

How it Works, by Karen Wrigglesworth

I was recently privileged to meet with Andrew Charleson, an ex-Wanganui boy who is now a structural engineer and Associate Professor at the Victoria University School of Architecture, in Wellington.

Andrew has just begun a 5-month sabbatical from his teaching commitments, with plans to further investigate his interest in finding a practical, low-tech means of strengthening the small adobe-brick houses of the Peruvian poor.

His idea is simple – cut used car tyres into narrow strips, and bind them around the houses like rubber bands to increase wall strength.

Car tyres are an inherently strong material, with a web of steel reinforcing encased in the rubber, rather like the reinforcing mesh inserted in concrete driveways and slab house foundations.  And, in our throw-away society, tyres are a plentiful, low-cost and under-utilised commodity – and readily available.

A large, magnitude 7.9 earthquake struck Peru in August 2007 – the same magnitude as the recent devastating earthquake in China.  In Pisco, the city closest to the epicenter, more than 80% of the adobe houses collapsed or sustained heavy damage, and over 400 people in the city were killed.

Buildings constructed of weak, unreinforced materials like concrete and adobe (earth) bricks can be a deathtrap for many when the shaking begins, even when a quake is only of moderate magnitude.

About Andrew

Born in Wanganui and educated at Durie Hill School, Wanganui Collegiate, and Canterbury University, Andrew has a Masters in Civil Engineering, specializing in earthquake engineering. (Civil engineering is more-or-less about designing things that shouldn’t move, like roads, bridges, buildings.)

He joined the Ministry of Works (MoW) before graduating, and was bonded to them for 5 years.  His early working life involved bridge design, supervision of an Upper Hutt subdivision for Housing Corp (which he admits was not exactly his thing!), and structural design (making sure a building’s structure, or skeleton, is strong and secure).

Andrew says, “While I was at university, I was required to do practical summer holiday work towards my degree.  I spent most of one summer helping to lay the foundations for the new Wanganui District Council buildings in Guyton St.  Another year I was at Lake Pukaki, surveying for the new hydro scheme.

Then, about five years after graduating, Andrew felt called to become involved with university students in a ‘semi-pastoral’ capacity.  He moved to Auckland, and stepped back from engineering for a couple of years.

When he returned to engineering two years later, it was to the same structural engineering role that he had left.  “But,” he says, “it took me the entire first year to get back my confidence with the day-to-day knowledge of the profession that we take for granted.  Things like the normal aggregate size for a certain situation, or the standard spacing for reinforcing rods.”

Andrew and his young family later spent two years in Indonesia, where Andrew held the position of Earthquake Engineering Advisor.

The family was in Indonesia for 2 1/2 years.  Andrew says, “It was very rewarding.  NZ had just provided Indonesia with a new earthquake design code, from which we helped the Indonesians to develop a code of their own.

“It was a culture shock for us, particularly with a young family.  And there were health issues.  But there was a strong sense of ‘calling’, as well.”

“Then, after another 5 years at the MoW back in NZ, and a total of 20 years of structural work experience, I made a conscious decision to take up a teaching opportunity at the School of Architecture.  Being a structural engineer challenged my technical abilities, but I wanted to grow other aspects of my personality – through teaching, and interacting more with people.

“I have found I greatly enjoy the interaction with my students, and architects, although, because I teach a compulsory subject – structures – I have to work hard to make the subject interesting and appealing.  My aim is to show students how structures is relevant to architectural design.  That was the premise for my first book – to show how structural elements, like ceiling beams, can become a design feature as well as a structural necessity.”

“I have just had my second book published.  It was difficult to write, but very rewarding.  Now I am focusing on my Peru research.  I will spend three months at Lima University, testing my tyre idea on their shaking table.

“I feel fortunate with the opportunities my work at Victoria University has brought me.  I enjoy the students, I enjoy the research.  And I enjoy the chance engineering gives me to make a difference.”

Karen Wrigglesworth is a local engineer and writer.  You can contact her on karen@inkcom.co.nz.