A piano-wire fence creates an inconspicuous and unobtrusive barrier between visitors and animals.

I recently saw a very tall example of a piano-wire fence at the Raptor Roost in the Albuquerque Zoo (ABQ Biopark). It's probably the tallest piano-wire fence I have seen in any zoo.

It's easy to see why it makes such a great barrier. The focus of my camera never picked up the fence and instead went right through to what matters: the animal.

While I was sorting out the photos for this post I had some ideas to improve the layout of the exhibit. The shape of the building could parallel the visitor's sight line - this would reverse the exhibit layout.

The way it's built the visitor looks against the back crossbeam (red arrow). On the right I show an alternate version: the crossbeam has been moved above the visitor's sight line which keeps the view clean and is less distracting. And it makes the space higher where it matters for the animals: in the back of the exhibit where the nests and perching sites are located.

The front facade is needlessly high. Photo below: the visitors standing in front of the exhibit would have to throw their heads way back to see the beam above.

The front facade only needs to be around 15 feet tall for the crossbeam to be out of view.
15 feet would be still an impressively tall piano-wire facade and it might avoid one of the disadvantages of every piano-wire fence: the longer the wires the easier they are to bend apart, creating an escape route for animals if they challenge the barrier.

In order to keep the animals at Raptor Roost from parting the piano-wire a horizontal wire has been woven into the fence about 12' above the ground (photo above).
The animals living here aren't much of a challenge for the fence: Golden Eagle Aquila chrysaetos, American Bald Eagle Haliaeetus leucocephalus, and Andean Condor Vultur gryphus.

I also noticed the bottom girder.

This would be easy to hide, either with plants or by simply covering it in dirt and rocks as shown below.

Here's another view of the bottom girder (labeled Original).
I photo-sketched an improved version below the Original.

Here's the complete list of improvements:

1. Cover up the bottom girder by raising the earth.
2. Reduce the amount of railing posts by half; change them from metal to wood.
3. Place tree trunks in front of the frame columns.
4. Change the pavement from concrete to earth (or it could be stamped concrete, but in either case something less formal than in the original photo).

Summary: I reduced the architecture and softened the overall look with warmer tones and natural elements to make it look less urban.

Below: a photo-sketch animation comparing the original photo and my improved version.

An equally efficient way of hiding the beam is with plants. And plants can be an advantage for the animals because even a narrow planting strip might translate into less stress for the animals.
(Here's a link to a study that discusses this issue.
The study, by Durham University with Chester Zoo, found that planting a meter-wide barrier of shrubs between the visitors' viewing platforms reduced the animals' stress-related behavior by more than half.)

For some part the girder is already hidden behind plants (this can be seen in the opening photos of the this post).
Overall I noticed what a great job the horticulture department did. Not only in this exhibit but throughout the zoo. Which isn't surprising because I was told the Biopark's Botanical Garden is in charge of the planting.
Once again this shows that a good horticulturist is best defense against an architect.

To end with the focus back on the piano wire, here's a photo from further away. The piano-wire fence doesn't even show in this photo - only the frame work does (a change link fence would stick out much more).

Here's a photo from another vantage point. The shrub and trees help to conceal and soften the framework.

Piano wire fence is easy on the eyes but demanding on the material. For it to work the wires need to be tightly wound which puts a lot of stress on the high tensile wire and all supporting parts.
But not to have the view obstructed by heavy fencing is worth the cost.
photo copyright unless otherwise noted 2015 Martin Schuchert

Bald Eagle - sketches by Laura Hamilton

Today, September 3rd, is International Vulture Awareness Day. What a great idea to celebrate these (partially) critically endangered birds with a day of their own!
Zoos, bird parks, rehabilitation centers, rescue stations and vulture lovers around the world are doing their part to raise awareness.
What can I do to mark this day?

I can show you how vultures are presented to the public in zoos.

I've never designed a vulture exhibit, so I decided to search my photo archives for examples of exhibits and I compiled my findings in this blog entry. The example exhibits shown below are from around the world emphasizing the "International" aspect of the International Vulture Awareness Day.
Large aviaries are the most prevalent, sometimes with a walk-through path for the visitor. I also found an open top exhibit with barrier moats.

The first example is from a zoo in Southern Germany presenting a commission of Griffon Vultures (Gyps fulvus).

Visitor view from close up.

The visitor path winds up the hill giving you another view of the exhibit from a higher vantage point.
In this photo I found the birds hard to see and I therefore marked them with arrows below.

There are five birds in the photo. Clicking the photo will enlarge it.

The Griffon vulture aviary as seen from a distance.

click on sign to enlarge

The sign gives the visitors basic facts about the birds. It also informs them that the birds once roamed these lands.
European zoos have played and are playing a vital role in reintroducing several vulture species into southern Europe. But, I can't remember any zoo that I visited in Europe bragging with large signage about it, in fact, I feel they are a bit too shy about their good work.

The next photos are from one of the vulture exhibits at the San Diego Zoo Safari Park near Escondido in California. Fittingly, the park exhibits the California Condor (gymnogyps californianus).

I like the transparency of the net fencing - and: what a great vista!

This photo shows the exhibit from further back. The visitor deck is raised, allowing visitors to be closer to birds that are perched higher up.

A detail of the California Condor exhibit at San Diego Zoo Safari Park

Above a view into the exhibit as seen from the visitor deck. The birds have tree snags, water, and animal skeletons.

Sign at the visitor deck

The California Condor is one of the zoo's success stories when it comes to breeding and reintroducing animals into their native habitat; to quote from the San Diego Zoo's website:

The San Diego Zoo Global is a leading partner in the efforts to save the California condor. In 1982, 22 birds remained in the wild. At that time, the San Diego Zoo was given permission to begin the first zoological propagation program for California condors. The program also involved the U.S. Fish and Wildlife Service, California Department of Fish and Game, the National Audubon Society, and the Los Angeles Zoo. Thanks to the conservation breeding program, within 25 years the population of California condors grew to more than 300 birds.

You can read the full article here: http://www.sandiegozoo.org/conservation/animals/birds/three_decades_of_the_condor/
And another interesting article from their web site:
http://www.sandiegozoo.org/animalbytes/t-condor.html

Crossing the Pacific to Japan, I found photos I took of a vulture exhibit at the Tama Zoo near Tokyo. The exhibit is quite large and round in shape allowing for the birds to fly in a circular pattern.

A turkey vulture circling around the tree at the center of the exhibit at the Tama Zoo.

A photo from a different angle.

The tree snag in the center is packed with five different species of birds of prey, not just vultures:

Mixed birds of prey exhibit at the Tama Zoo, Japan.

Below is a photo of the most colorful vulture, a king vulture (Sarcorhamphus papa) on display at the National Aviary . The National Aviary, located in Pittsburgh, Pennsylvania, isn't funded or run by the U.S. government, like the National Zoo in Washington D.C.is. Given that they have quite an exotic bird collection the epithet "National" is something of a misnomer on that end too. The king vulture's name, however, is dead on:

At this exhibit the barrier of choice between visitor and vultures is glass, allowing for net-free photos.

There is some edifice behind the exhibit, which is thankfully hidden from view by the wood wall. The lush and tropical planting fits to the exotic character of the birds and to their preferred habitat of tropical lowland forests.

Besides taking net-free photos, glass allows you to get very close to the animal. The photo below is from a vulture exhibit at the Amersfoort Zoo in Holland.

Here the same photo un-cropped:

The transparency of this glass barrier works particularly well here because the visitor is in a dark, shaded place that doesn't create reflection onto the glass pane. In fact it worked so perfectly in places that I can imagine visitors occasionally running into the glass (and birds might too).
The theming and the placement of the glass further helped to disguise and conceal the barrier, as you can see in this photo:

Below, a different view of the same exhibit.

Carcasses are scattered on the floor:
A glass barrier needs to be clean and free of reflection for it to serve its purpose. Fortunately, both can be controlled. A designer will go to great lengths to prevent reflection in most circumstances. Clean glass might be largely a management issue, but the designer can help by making cleaning the glass easier and thereby likelier through easy accessibility. Despite the fact that there was quite a lot of glass in this exhibit, it was spanking clean the day I was there. The photo below shows how reflection creates distraction along the visitor sight-line.

Reflection on glass barrier

This is not to say that this was a design gaffe - on the contrary, the exhibit worked great from the visitors' point of view - but the photo allows me to show rather then to tell about one of the downsides of glass: reflection.
The other disadvantage of glass is a psychological aspect: although visually pleasing, glass creates quite a disconnect from the animal even if one stands nose to nose with the animal. I experienced this once with a tiger and once with a gorilla. In both cases I saw the animals through the glass as a visitor ;there were just inches between me and the animals, and then I stepped behind the scene with a keeper to see the back holding area where cages and chutes consisted of metal bars. When the animals came up, I took notice and stepped back.
It was scary and impressive; the animals appeared stronger, bigger, and wilder - gone was the cuddly kitty, instead I was faced with a wild tiger. This transformation happened in my head, the animals were the same, whether behind glass or behind bars, and quite uninterested in me. Anybody that has gone to a zoo with a public training wall at a tiger exhibit where you can come close to the animal knows what I am talking about.
The bottom line of this digression, as the photos from Amersfoort Zoo show, glass is a great barrier but it has its shortcomings.

Back to International Vulture Awareness Day and how these birds are displayed in zoos:

The Living Desert Museum in Southern California has a walk through aviary which allows you to see the birds with no barrier between you and them.

The sign reads "PLEASE STAY ON PATH"

There is a little stone bench in the lower right corner of the photo. How much closer can you get to these animals?

Above: A black turkey vulture (Coragyps atratus) looking down at me where I'm standing on the visitor path.

A completely different concept in displaying vultures is the open top exhibit in the next example. This exhibit is situated in the African Woods section of the San Diego Zoo Safari Park. The birds are confined by a ha-ha and some wire fencing, both mostly hidden from public view. The photos here are about ten years old; by now the exhibited species might have changed - if not the exhibit itself.

At the time of my visit they had Griffon Vultures (Gyps fulvus) on display. The downside of this type of exhibit is that you need to clip the birds' feathers to keep them from taking off; and another potential disadvantage is that other birds can enter the enclosure, which might lead to fighting or to high blood pressure in the vet department.

In the photo above the Griffon vultures have company from one heron and two turkey vultures.
Since it is quite common to see several vulture species around one carcass I guess it just got more educational - but how to do you explain Old World and New World vultures in one exhibit? Does the visitor even care? For the visitor the enclosure becomes more colorful and more active...

I remember the display as beautiful and effective from my visitor vantage point. What made it even more interesting was that I could see antelopes behind the exhibit; it was one spectacular habitat display. I wish I had a photo of the vultures with the antelopes in the background; instead I found a photo I took in Kenya that reminded me of this exhibit:

A venue of vultures in front of a herd of wildebeests.

When it comes to zoo design: Let nature be the guide.

Summing up: I was impressed by the diversity of displays with which zoos raise appreciation for vultures. Creating aviaries large enough for these birds to fly takes up a lot of land and I was wondering, couldn't you make the most of the real estate by adding ground dwelling animals to the display?
I did a search for mixed vulture exhibits and found two amazing exhibits at ZooLex.org.
The first one is located at Nordhorn Zoo in northern Germany where they mix Griffon vultures with an Ibex herd (Capra ibex).

Visitors can enter the exhibit and view the birds from behind a railing. Here is a link to more photos and a thorough description of the exhibit:

http://www.zoolex.org/zoolexcgi/view.py?id=778

The Nature and Animal Park Goldau, in Switzerland, mixes bearded vultures (Gypaetus barbatus) with snow hares (Lepus timidus). How cool can you get?

More photos of this exhibit and a lot of useful information (cost and size of the exhibit, etc.) can be found at: http://www.zoolex.org/zoolexcgi/view.py?id=788

Finally, two links I highly recommended for further reading.
Peter Dickenson writes about the dangers vultures are facing in the wild:

http://peterdickinson.hubpages.com/hub/International-Vulture-Awareness-Day

and
The founders of the International Vulture Awareness Day put a site up where you can find out what zoos and other organizations are doing to celebrate this day. Sign up and participate at:

http://www.vultureday.org/2011/index.php

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For this blog entry I wanted to know what a group of vultures is called. Here is what I found:
"Wake, committee, or venue" from wikipedia.org
"Wast, committee, meal, vortex, venue and even wake" from wiki.answers.com
"Vultures circling in the air are a Kettle" from vulturesociety.homestead.com

Vulture illustration by Laura Hamilton

Happy

International

Vulture

Awareness

Day

wild-design

zoo and aquarium design

Piano-Wire Fence: keeping the focus on the animal not the barrier / May 22, 2015 by Martin

Celebrating International Vulture Awareness Day / September 3, 2011 by Martin