Polar bears are specifically adapted to live in cold environments. Their physiology and behaviour are all geared for the retention of heat in a cold climate. While polar bears in the southern areas of their natural range may experience warm weather at times, it is usually brief and nothing at all like the climate in southern locales. As well, they have the ability to employ various strategies to keep cool, such as swimming in arctic waters, digging dens or day beds in shady soil areas down to the permafrost and reducing the quantity of fat in their diets.
Of considerable concern is the fact that Yupi cannot obtain proper relief from the heat. Polar bears have evolved to live in extremely cold climates and are physiologically and behaviourally adapted to cold conditions. They suffer in warm climates. Even if the Morelia Zoo implemented measures to address climate concerns, they would be insufficient to adequately address the problems.
The Morelia climate is completely unlike that found in northern regions, so keeping cool is a major challenge for Yupi. At present, she has only two options for cooling: swimming in her pool (since the pool is not refrigerated, it may not provide adequate relief) or seeking whatever shade is cast by the walls of her enclosure.
Lack of Space
The exhibit is grossly undersized, providing at most a few hundred square meters of dry space. There is not enough room to facilitate species-typical movements and behaviours. Polar bears are the widest ranging terrestrial mammal species on earth, so they need extremely large spaces, considerably larger than any urban zoo can provide. Given that hundreds of polar bears are currently kept in captivity, they should all ideally be provided with expansive, naturalistic paddocks that allow them to roam, dig, construct day beds, climb to elevated viewing stations and express a broad range of other species-typical behaviours.
In a 2003 paper entitled Captivity effects on wide-ranging carnivores, published in the prestigious science journal Nature, Oxford University researchers Ros Clubb and Georgia Mason indicate that wide-ranging carnivores "show the most evidence of stress and/or psychological dysfunction in captivity." They say that husbandry of wide-ranging animals needs to be substantially improved, including the provision of extra space; "a polar bear's typical enclosure size…is about one-millionth of its minimum home-range size."
The Morelia Zoo polar bear exhibit is extremely small and hinders normal movement patterns and species-typical behaviours.
Polar bears are complex, intelligent animals that require a great deal of stimulation. Yupi's exhibit is flat and barren, consisting of a concrete peninsula (with two vertical tree stumps and one dead tree encased in cement - hot-wired to prevent climbing) and a pool. There are no other features or furnishings; nothing that would encourage natural movements or species-typical behaviours.
There is also no object enrichment. In the wild polar bears manipulate a range of natural items. Unfortunately, Yupi has nothing to push, pull, chew on, dig, tear apart, climb or manipulate. Apparently, the zoo made past attempts at enrichment but they were abandoned. No further attempts at enrichment have taken place.
In the wild, polar bears employ hearing, sight and smell as they travel and hunt. Yupi has little visual stimulation as she is only able to see the interior of her enclosure (there are no elevated viewing stations for her to use) and she has no olfactory stimulation from novel scents, objects, etc.
Yupi’s daily management regime is predictable and routine. There is no environmental enrichment and feeding occurs on a schedule at specific times each day. Yupi does not have any visual stimulation because she is surrounded by walls, so her only real contact with the outside world is by looking through the windows at the visitor viewing station.
The polar bear exhibit is an antiquated design that is no longer acceptable. Like similar old-style exhibits, it appears to have been constructed for security, ease of maintenance and to resemble an arctic pack ice environment. While it may accomplish the first two criteria, it does not visually or biologically simulate the environment experienced by polar bears in nature.
The Morelia polar bear exhibit is a simplistic, outdated design that does not take into account the behavioural biology and natural history of polar bears.
Probably the most alarming aspect of management is the fact that Yupi is confined in her holding area (a dank, barren, concrete bunker) for the majority of each day, in conditions far worse than her main enclosure. According to staff, Yupi is locked in her off-exhibit area 16-17 hours each day. Presumably, this scheduling coincides with the arrival and departure of zoo staff each day. The holding area is small, dark, damp and barren. It has little natural light and no soft areas for resting. While Yupi's main exhibit area is grossly substandard, the holding area where Yupi spends most of her time is much worse. Under no circumstances should Yupi be confined in this space for the majority of each day.
The entire enclosure, including the off-exhibit holding area, is comprised of hard concrete floor surfaces. Not only are these surfaces uncomfortable to stand, sit and lie on, they may be physically damaging as well. Additionally, they provide none of the behavioural opportunities (e.g., digging, foraging) that natural, soft substrates do.
Hard substrates can also be thermally problematic. In some cases, they absorb heat from sunlight during the daytime and radiate that heat outward at night. While the Morelia Zoo polar bear exhibit floor is painted and may reflect sunlight reducing daytime heat absorption, it was still hot to the touch during an inspection made by Zoocheck.
Zoocheck believes that soft substrate materials have not be provided for Yupi for following reasons:
1) the zoo's misconceptions about the biology and behaviour of polar bears;
2) to prevent debris being tracked into the pool clouding the water and obstructing visitor viewing, and
3) to prevent debris from clogging the filtration system.
The floor surfaces in Yupi's exhibit are entirely inappropriate. Polar bears should not be kept on hard surfaces.
Lack of Shade
There were few shaded areas in Yupi's exhibit, although at certain times of the day the walls on either side of the concrete peninsula and the alcove at the back of the exhibit may provide some shade. Regardless, there were no permanent structures in the exhibit to provide shade and there was no overhead shade cloth or netting. Polar bears are prone to overheating, even in relatively cold temperatures, so they need to be able to cool off. Yupi is unable to obtain sufficient long-term relief from Morelia's temperature and humidity.
Yupi was observed sitting for relatively long periods of time in one location on the concrete peninsula and lying prone in that position at other times. She was also observed swimming in a repetitive fashion along the front of the underwater observation window.
Sitting, lying or standing for long periods of time is abnormal and an indication that animal-environment interaction is suppressed. As well, the swimming pattern appeared to be stereotypic. While it is difficult to precisely determine the motivations for particular behaviours in animals, it is entirely likely that the lack of space and barren conditions have caused boredom, frustration and deprivation, leaving Yupi with few behaviours to express except those we observed. It was determined by Zoocheck that Yupi is inactive approximately 75% of the time, while she is in the on-display area.
Along with whales and elephants, polar bears are the most controversial animals in the zoo world. Animal welfare advocates across the globe are working toward an end to the keeping of polar bears in zoos as their biological and behavioural needs cannot be met. According to British veterinarian/zoo inspector Dr. John Gripper, “In my visits and inspections of zoos around the world, I find that the polar bear is probably the most difficult animal to confine in a zoo enclosure without showing abnormal behaviour.”
Stefan Abbott Ormrod, in his report A Review of Captive Polar Bears In Great Britain and Ireland (1992), “It is clear that polar bears have great difficulty in adjusting to the conditions of captivity. This is especially clear when one examines the widespread incidence of aberrant behaviours.”
In his book Last Animals At The Zoo, Colin Tudge states that:
Polar bears have been a huge challenge to zoos. They are ... ‘easy to keep alive’, and they breed reasonably well these days but they are among the
most notorious of all stereotypers: pacing and head-rolling
. Even zoo enthusiasts have often doubted whether polar bears should be kept in captivity.