black bear (Selenarctos
O'Grady, G. Law, H. Boyle, A. MacDonald & J. Johnstone
in 1995 the Glasgow Zoological Society was approached by officials
of Dumbarton District Council for advice on a local wildlife park,
the Cameron Loch Lomond Wildlife Park. Although the park was no
longer open to the public, the problem of the disposal of stock
remained. Earlier, escapes of bears in the collection had prejudiced
public safety and the 1981 Zoo Licensing Act had placed the responsibility
for zoos on local authorities.
the assistance of the National Federation of Zoological Gardens
of Great Britain and Ireland, the majority of bears, Brown bears
Ursus arctos and Black bears Ursus (Euarctos) americanus,
were moved to the Windsor Safari Park but it proved impossible find
a home for a group of 2.4 Himalayan black bears Selenarctos thibetanus.
owners of the park, the Alloa Brewery Company Limited, and Clive
Hollands, Director of the St Andrew Animal Fund repeatedly approached
the Society to house the bears at Glasgow but because of our experience
with Polar bears Thalarctos maritimus (Law et al., 1986),
we were unwilling to proceed unless all modern welfare requirements
could be satisfied. The Society finally agreed to accept responsibility
after agreeing a written statement of policy and preparing detailed
financial costings. The Alloa Brewery Company offered £30,000 to
sponsor the project and as much of the original fencing from the
bear park as we required.
AND PERIMETER FENCING
in some respects, management of the bears at Loch Lomond had not
accorded with modern zoo practice, there were lessons to be learned
and in the designing of the new exhibit careful attention was paid
to the bears' behaviour patterns. For example, none of the bears
had liked the small, half-buried concrete houses, which were damp,
and in which the smaller individuals could be cornered by a larger
animal. All the bears had dug their own underground dens, invariably
in dry sandy south-facing banks, and above ground nests had been
positioned where they had good views of the approach of visitors
visits to safari parks housing bears, we observed that although
many of the enclosures were large, from 4 to 6 ha, they were flat
to permit vehicle access to all parts and to enable the staff to
round up the bears at night. This terrain seemed to be lacking in
interest both for visitors and the occupants and it was clear from
our observations at Loch Lomond, where the animals had been housed
in an enclosure of nearly 6 ha, that the bears were in the habit
of monitoring everything in their field of view.
Society owns just over 40 ha of land of which only 18 ha had been
developed and creating an exhibit of the size contemplated required
the provision of secure boundary fencing for part of the undeveloped
site selected was situated in a valley containing many mature trees
and thick with undergrowth, which we felt would offer the type of
'enriched' habitat to make a sufficiently stimulating enclosure
for the bears. Based on experience with Polar bears, it was considered
that two connected outdoor enclosures were essential. Both for security
and ease of access the indoor quarters and smaller enclosure, c.
0-5 ha, were located on top of the hill. The adjacent enclosure,
nearly 1-5 ha in extent, incorporated a section of the thickly wooded,
35 degree slope and part of a stream which flows through the bottom
of the valley
of the steepness of the terrain, the fencing, 900m in length, proved
extremely difficult to erect in places. In accordance with the recommendations
of 1981 Zoo Licensing Act, the fence wire is buried to a depth of
at least 1m with an inward facing return of 1m. A 1m wide concrete
pathway runs around the inside of the fence of the top enclosure.
Above ground the 2.5 m high weldmesh fence is topped by 1.2m of
corrugated iron along its entire length to prevent the animals from
climbing over it. Although the iron is potentially unsightly, discreet
painting and careful siting close into the bank or against hedging,
as well as additional planting on the outside of the fence, has
softened its impact considerably. The 120 m long section of fencing
along the valley bottom is almost invisible on the other side of
the valley because it is tight into the banking below and hidden
by vegetation. As electric fencing is not in general effective for
bears, the alternative would have been a prohibitively expensive
3.5 m high brick or blockwork wall. The cost of the perimeter barrier
is probably the main reason why the majority of zoo bear enclosures
world-wide are still too small. This group of bears was 'fence trained'
on arrival and have never attempted to climb the fence. We appreciate
that to release bears used to traditional zoo 'cages' into
such an enclosure might be more difficult.
the bears were on the platform in the top enclosure, the corrugated
sheeting obscured the visitor's view and it has been replaced in
two places with 6 mm bullet-proof clear plastic Lexan sheeting.
Although this material will scratch (there is a more expensive non-scratchable
version), as it is above head height for both humans and bears,
this has not been a problem. We are now experimenting with alternatives
to the corrugated iron and in time we intend to replace it wherever
possible where it is in public view.
indoor accommodation consists of four interconnecting dens with
weldmesh fronts and a service area which includes a food preparation
section. The den sizes were based on the bear dens at West Berlin
Zoo (Klos, 1974), the two outer dens measuring c. 4 x 2.3 m and
the two smaller dens c. 2.6 x 2.6 m. They are c. 2.2 m in height
and roofed with pre-cast concrete which enables the full height
to be used for the animals and also allows for wire hawsers to be
run above the concrete slabs to control the heavy steel guillotine
exterior doors, which give access to the outside enclosure. These
doors, which are operated from the service area, are counterweighted
to assist lifting and enable a keeper to offer food items through
the weldmesh at the front of the den to keep the animals' attention
while the doors are closed. They can be locked into the open or
closed positions and since the bears, assisted by the counterweight,
are able to open them from outside, this has proved to be an essential
feature when keepers are working in the dens. The sliding doors
between dens are top hung on bogie wheels housed in a mild-steel
track, there is no bottom runner and only short self-clearing brackets
are required to hold the door securely.
den is fitted with a wooden platform, 1.5 m high, onto which the
bears climb to rest and feed. We tried to simulate the tree nests
of wild bears by providing hanging baskets, two of which are bolted
into the corners 2m from the floor in the larger dens. The baskets
are about 1 m deep and consist of flat and round bars, lined with
weldmesh to retain the bedding. The two central dens are fitted
with single, smaller, less deep baskets. Since bears avoid soiling
their nests, by defecating and urinating over the rim keeping their
bedding material clean and dry, the provision of these has not only
been popular with the bears but also simplifies cleaning procedures.
use, we found that one modification was desirable. Although the
bears are good climbers, we noticed that when climbing down from
the nests or ledges the females were cautious, lowering themselves
backwards and feeling with hind paw for a projection for support.
We therefore arranged for short blunt metal crossbars to be welded
to the uprights and these are now used routinely by the bears when
the dens are fairly warm and well-ventilated, we believe they would
be improved with the addition of underfloor heating and we hope
to install this in due course.
0.5 m upper enclosure, connecting with the house, is the bears'
'adventure playground' and feeding area. A wooden structure
with four platforms placed at increasing heights made of telegraph
poles and wooden planks allows food to be presented in a variety
of ways as well as giving the bears a view which covers most of
the Zoo. The legs of the structure have wooden pegs fitted at various
heights on with food items can be speared. Some of these can just
be reached by the animals with their claws while standing upright,
while others require them to climb the poles to reach them. To facilitate
climbing in wet weather hemp rope has been wound in a spiral on
some of the platform legs. From one of the lower platforms, a notched
pole slopes to the ground at an angle of 50-55 degrees with a blunted
hook attached to its underside some three-quarters of the way up
from which food is hung. The bears must have a good balance to climb
the pole and retrieve the food.
tallest platform is c.5 m From the ground and although the male
does go to the top without hesitation, we believe that it may have
been an improvement if the construction had been spiral so that
the animals always had a wall against each shoulder when ascending
clay pipes, 23 cm in diameter and 45 cm deep with 2.5 cm of gravel
at the bottom for drainage, have been sunk into the ground to hold
food items which the bears scoop out with their paws or stab with
their claws. The bears, taking great care, can remove uncooked eggs
from the pipes without breaking them. A 1 m length of piping of
the same diameter is left in the enclosure with food inside just
out of paw reach and the bears must roll the pipe, which has a flare
jointing lip at one end, to cause the food to fall out of the end.
Scatter feeds of raisins and other small items are spread around
the enclosure or hidden in a large pile or rocks to encourage the
animals to forage. The rock pile also enables the bears to avoid
one another in times of conflict or stress.
heavy duty plastic fish farm tank 3 m in diameter and 1 m deep with
a 1800 litre capacity was sunk into the ground as a pool. Rosenthal
(unpubl.) observed that Black bears at Oklahoma Zoo were afraid
to use a pool if it was too deep. When the pool was first introduced
we scattered food in it to encourage the bears to use it and were
interested to see them retrieve carrots, which had sunk to the bottom,
by feeling with the hind paw and lifting the food out between the
claws. Our bears enjoyed the pool especially during a spell of unusually
hot weather when the male which appeared to be particularly distressed
by the heat, spent many hours in the water. We intend to add a further
two or three similar pools to reduce competition for the facility.
Other additions that we hope to install are more logs and pipes,
heavy rope hammocks supported between the uprights of the platform,
a 4 m tall honey log, and a number of metal baskets on legs with
pitched roofs to provide each bear with a relatively private, draught
and damp-free, outdoor bed in full view of the public.
large wooded enclosure is reached from the feeding area via a top-hung
sliding door of similar pattern to that used between the indoor
dens. The valley has been left as natural as possible with no additions
of artificial furniture. There are several mature trees growing
to heights of 15 m or more, small younger trees of various species
and an overgrown hawthorn Crataegus hedge, with a flourishing undergrowth
of brambles, thistles, rose-bay willow herb and ferns. The enclosure
encourages the bears to carry out a wide variety of behaviours,
including different types of feeding, such as grazing, digging for
roots and tearing apart decaying logs, presumably in search of grubs.
They also eat wild berries and climb the hawthorn bushes to reach
the ripe fruit in the autumn.
in the wild has shown that Black bears can seriously damage favoured
feeding trees and 'some are so damaged that little beyond the
tree trunk and branch stumps remain' (Schaller et al.,1989).
In time it will probably be necessary to protect some of our mature
trees with guards.
encourage more widespread use of the enclosure, the keepers have
devised a system of scent trails. This simple technique consists
of tying a 'smelly' food item (meat or herring) onto a piece
of twine and trailing it around the enclosure. To avoid predictable
hunts not all trails lead to a reward.
bears make nests in the trees and on the ground. The male is a particularly
skilled nest builder and has several beds usually sited at the foot
of a mature tree, which he uses in turn depending on the weather
conditions. The nests are similar to those described in the wild
(Schaller et al., 1985), being constructed of 20 or 30 shoots or
small branches broken off from a nearby tree or bush, ash Fraxinus
excelsior or willow Sulix are favoured by our animals, and lined
with twigs, grasses and leaves. One of the nests showed evidence
of careful construction with the branches interwoven in an elaborate
manner rather than piled haphazardly in the concave at the tree's
base. One of the females made a feeding nest 8 m above ground in
the fork of a horse chestnut Aesculus hippocastanum, constructing
it, in the manner of wild bears, by bending the nearby branches,
chewing off the shoots and piling the bent or broken branches below
her to form a crude platform, the remains of which could still be
seen the following February after the winter storms.
bears have also dug wet weather dens into the hillside and under
an old tree root. The latter, built by the male is often used and
added to, the animal scraping out the soil and lining the nest with
large twigs and dried grasses. These wet weather nests have been
used in winter for a period of several days for semi-hibernation.
bears are seasonal in their activity and if allowed will feed voraciously
in late summer to gain weight for semi-hibernation during the winter.
If they are not allowed to feed to their maximum capacity they will
remain active throughout the winter months. Our bears show a substantial
weight gain during the summer and it is difficult to supply them
with enough food to satisfy them. In the winter they retire to their
indoor baskets for months at a time. Even the presence of the noisiest
keeper does not seem to disturb them and, since it is not possible
for the bears to descend from the baskets quickly even if they do
wake, the cage area under the basket can be cleaned without fear
bears have a wide range of vocalisations. A loud "tut tut",
apparently made by the bear snapping its tongue against the roof
of its mouth, seems to be used as one bear approaches another but
is never used towards the keepers. A loud hiss, caused by a fast
exhalation of breath is used as a threat or warning.
the most alarming sound that the bears produced was heard when they
were involved in squabbles during the introductory period. A very
loud human-like scream, leading one to believe that the fighting
was causing nothing less than fatal injuries, was produced but when
the bears were separated little sign of damage could be found and
it would seem that their huge neck ruffs protect them.
the end of 1989 the exhibit housed a 1.4 bears, the male being particularly
active. The design of the exhibit was intended to eliminate the
major criticism of keeping of bears in captivity, that is, the lack
of sufficient stimulation, leading to stereotypic behaviour. The
large foraging enclosure and the many artefacts in the top enclosure
provide a continuous source of changing interest.
of the concerns expressed at the plan was the enclosure was so large
and contained so much undergrowth that the visitors would have difficulty
in seeing the animals. In practice this has been found not to be
so. When necessary, the bears can be easily enticed into the top
enclosure and they are frequently on view resting on the platforms
rather than hiding in the vegetation. We apparently underestimated
the interest the bears take in the people.
Society would like to thank the many individuals and organisations
for their help in the complex project. In particular our thanks
St Andrew Animal Fund
Animals Rights Network;
Society for the Prevention of Vivisection;
Society for the Prevention of Cruelty to Animals;
Wheater, Director of Edinburgh Zoo;
Pape of Ravensden Zoo;
Clubb of Clubb-Chipperfield;
Federation of Zoological Gardens of Great Britain and Ireland.
We would also like to thank the members of our Zoological Society,
the staff and our veterinary surgeons for their constant encouragement
MENTION IN THE TEXT
polycarbonate sheeting, manufactured by GE Plastics Ltd. Birchwood
Park, Risley, Warrington, Cheshire, Great Britain.
H.-G. (1974): New bear exhibit in the West Berlin Zoo. Int.
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G., Boyle, H. & Johnston, J. (1986): Notes on polar bear management
at Glasgow Zoo. Ratel 13(2): 56-58.
M. (Unpublished): Lincoln Park Zoo management survey of bears
in captivity. Internal report 1988.
G. B., JINCHU, H., WENSHI, P. & JING, Z. (1985): The giant
pandas of Wolong. Chicago: University of Chicago Press.
G. B., QITAO, T., JOHNSON, K. G., XIAOMING, W., HENIINC,, S. &
Jinchu, H. (1989): The feeding ecology of giant pandas and Asiatic
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